A revision of Afrotropical Chyromyidae (excluding Gymnochiromyia Hendel) (Diptera: Schizophora), with the recognition of two subfamilies and the description of new genera.
Abstract: An account is provided of the family Chyromyidae in the Afrotropical Region and taxonomic characters are re-examined and discussed. A division of the family into two subfamilies, Chyromyinae and Aphaniosominae subfam. n., is proposed and a cladistic analysis corroborates the generic concepts. Illustrated keys are provided to aid identification of both sexes of all included species. African species in the genus Gymnochiromyia Hendel have been reviewed elsewhere (Ebejer 2008b) and are not included in the current revision. Five new genera are described, viz. Krifomyia gen. n., Oroschyromya gen. n., Notiochyromya gen. n., Paraphaniosoma gen. n. and Tethysimyia gen. n. Aphaniosoma sexvittatum Lamb, 1914, is newly assigned to Paraphaniosoma gen. n. and Aphaniosoma deemingi Ebejer, 1996, to Tethysimyia gen. n. Rhicnoessa minutissima Bezzi, 1908, previously removed from Canacidae (as Tethininae) and placed in Chyromyidae by Munari in 1994, is re-examined and newly assigned to Krifomyia gen. n., Chyromya dubia Lamb, 1914, to Oroschyromya gen. n. and C. sexspinosa Lamb, 1914 to Notiochyromya gen. n. The following 27 species are described as new: Oroschyromya affinis sp. n., O. bicolor sp. n., O. elgonae sp. n., O. elongata sp. n., O. fusciceps sp. n., O. gracilipes sp. n., and O. peruncinata sp. n.; Notiochyromyafiligera sp. n., N. lucida sp. n., N. monticola sp. n., and N. tripunctata sp. n.; Somatiosoma awashensis sp. n., S. grandicornis sp. n., S. messumensis sp. n., and S. setipygum sp. n.; Aphaniosoma aethiops sp. n., A. aldabrensis sp. n., A. atriceps sp. n., A. conspicuum sp. n.,A.flavescens sp. n., A. frequens sp. n., A. gaiasicum sp. n., A. kirkspriggsi sp. n., A. micropygum sp. n., A.pullum sp. n., A. trilobatum sp. n., and A. ugabensis sp. n.

KEY WORDS: Chyromyidae, Afrotropical, biology, faunistics, new genera, new species, systematics.
Article Type: Report
Subject: Zoology (Identification and classification)
Zoology (Research)
Author: Ebejer, Martin J.
Pub Date: 12/01/2009
Publication: Name: African Invertebrates Publisher: The Council of Natal Museum Audience: Academic Format: Magazine/Journal Subject: Zoology and wildlife conservation Copyright: COPYRIGHT 2009 The Council of Natal Museum ISSN: 1681-5556
Issue: Date: Dec, 2009 Source Volume: 50 Source Issue: 2
Topic: Event Code: 310 Science & research
Geographic: Geographic Scope: South Africa Geographic Code: 6SOUT South Africa
Accession Number: 219376293
Full Text: INTRODUCTION

The Chyromyidae is a family of 177 named species of small to very small acalyptrate flies (0.75-4.5 mm) currently classified close to the Heleomyzinae and Sphaerocerinae, which D.K. McAlpine (2007) grouped together under one family, the Heteromyzidae. All genera within the Chyromyidae agree more closely to this taxon than to any other group of acalyptrate flies. Most species have a pale yellow integument and bright iridescent green, red or purple eyes. The family is represented in all continents except Antarctica but, apart from the western Palaearctic, all other zoogeographical regions remain poorly studied. No comprehensive taxonomic study reviewing the generic limits of species in the family has previously been attempted.

The paucity of species known from the Afrotropical Region must be regarded as merely a reflection of the scant attention that the family has received. In a brief overview of the family, with an emphasis on Namibian species, it was indicated that further species awaited description (Ebejer 2000). Since then, an appreciation of additional taxonomic characters and the examination of a large number of additional specimens have delayed further taxonomic publication, pending resolution of generic limits. For this purpose, an examination of material from other regions was also required.

Only eight species in four genera are listed in the Afrotropical Catalogue (Cogan 1980). These eight include all those described from the Seychelles and Cape Verde [Cabo Verde]. Subsequently, additional species were described from the southern part of the Arabian Peninsula and one other from Yemen and Ethiopia (Ebejer 1996). The following are included in this contribution: Aphaniosoma approximatum Becker, 1903; A. dhofaricum Ebejer, 1996; A. fissum Collin, 1949; A. gallagheri Ebejer, 1996; A. harteni Ebejer, 1996; and A. lamellatum Collin, 1949. A fifth species (as Somatiosoma sp.) was recognised as new (Ebejer 1996) but was not described as males were not available for study. Since then, males have become available and it is now apparent that it is the second most widespread species in the genus and the only one to reach the southern Palaearctic (Ebejer 2008a). Of the species listed in the Afrotropical Catalogue (Cogan 1980), A. approximatum is a misidentification (see description of A. frequens sp. n. below), while the listed record of Gymnochiromyia flavella (Zetterstedt, 1848) from the island of St Helena has been questioned by Ebejer (2008b).

Lamb (1914) described four species from the Seychelles, namely: Chiromyia (= Chyromya) dubia, C. sexspinosa, C. hirtiscutellata and Aphaniosoma sexvittata. All the type material of these four species, housed in CUMZ and BMNH, has been examined, and all the species are here assigned to new genera. In the case of C. (C.) dubia, the type series comprises species in two genera, and in the case of C. hirtiscutellata, material of two species. These are treated in detail below.

Frey (1958) described two species of Chyromyidae from the Cape Verde, proposing the new subgenus Somatiosoma to accommodate one of these (S. nitescens), while the second (suboculicauda) he ascribed to Aphaniosoma. The types of S. nitescens were not examined, as the figures given by Frey and the description are adequate to identify and separate this species from congeners. On the other hand, the types of A. suboculicauda (MZH) were re-examined as part of this study and details are provided below.

As part of a study of African Tethinidae, Munari (1994) examined the types of Rhicnoessa minutissima Bezzi, 1908, recognising these as Chyromyidae and not Tethinidae. These types have been re-examined here and the current status of this species is discussed below under Krifomyia gen. n.

The genus Gymnochiromyia was revised recently (Ebejer 2008b), and 14 new species were described and keyed from southern Africa. For this reason, this genus is omitted from the current revision.

BIOLOGY AND ECOLOGY

The biology and ecology of the Chyromyidae are poorly known, the little that is known having been summarised by Ferrar (1987). In the Palaearctic Region, species of Chyromya and Gymnochiromyia have been reared from debris in the hollows of trees, from mammal nests and burrows, and from birds' nests (Collin 1933; Rotheray 1989). Chyromya is also recorded as having been reared from bat guano (Smith 1989). Aphaniosoma (s. str.) was reared from leaf litter beneath Salicornia (Chenopodaceae) and Phragmites (Graminae) in Malta (Ebejer 1996) and from a rodent nest on a beach in southern Spain (Ebejer & Deeming 1997).

Rotheray's (1989) tabulation of E.B. Basden's records of a diversity of families of Diptera in Britain indicated that 36.03 % of individuals reared from 19 of 106 burrows and nests of 11 species of mammal were Chyromyidae. These were mainly Chyromya flava (L., 1758) from the nest of the hedgehog, Erinaceus europaeus L. and from rabbit burrows, Oryctolagus cuniculus (L.), and Gymnochiromyia inermis (Collin, 1933) from the dreys of the squirrels Sciurus carolinensis Gmelin and S. vulgaris L. Almost 600 specimens of G. inermis reared from a squirrel's drey, make this by far the largest number of individuals from a single nest. Only 2.29 % of individuals were Chyromyidae, reared from 12 of 228 bird nests of 48 species, and all were G. inermis.

Larval feeding habits are unknown. From the location and circumstances in which puparia have been found, it must be assumed that larvae graze on decaying organic matter, the microhabitat probably being as significant as the larval food source itself. Most records, at least in so far as they refer to Chyromya and Gymnochiromyia, suggest that the larvae require the droppings of vertebrates. There are records, however, that indicate that this may not be true for all species in the family. Chandler (1973) and Cogan (1978), for example, recorded the rearing of Gymnochiromyia from decaying marram grass and elm wood debris but, as no details were provided, these records do not directly negate the assumption that vertebrate droppings may be an important food resource.

The only published descriptions of immature stages are of the puparia (with associated cephalopharyngeal skeletons) of Gymnochiromyia and Aphaniosoma (Ebejer & Deeming 1997; Deeming 1998) and Chyromya (Gibbs 2007), all from the Palaearctic Region.

Adults are usually encountered when sweeping vegetation with a hand net in suitable habitats, such as vegetated coastal dunes, grasses and Tamarisk trees near saltmarshes, and sometimes sweeping lower branches of trees along broadleaved woodland edges. They can also be collected, often in vast numbers, in pan traps and Malaise traps. Some species, in particular Aphaniosoma, frequently come to light. Adults are occasionally observed at flowers, including those of Convolvulus (Convolvulaceae) and Matricaria (Compositae) (Collin 1949), Hibiscus (Malvaceae) (Colless & McAlpine 1970), Ipomoea (Convolvulaceae) (Wheeler & Sinclair 1994), Euphorbia (Euphorbiaceae), Foeniculum (Umbelliferae) and Tamarix (Tamaricaceae) (Ebejer 1996).

The Chyromyidae are found throughout the year in the hotter regions of the world. In temperate regions, the general preference is for the hot and/or dry season. Thus, April to October is the main flight period in the northern hemisphere; conversely, in southern Africa, it is October to March.

In general, preferred habitats for the family comprise vegetated areas near still, saline or fresh water bodies within hot dry areas, or along the coast. There are exceptions, however. Aphaniosoma socium Collin, for example, is a north European species that appears to favour damp, regenerating landfill sites and old mines (Bahrmann 2006; Ebejer et al. 2001). Chyromya spp. are generally associated with broadleaved woodland or savannah, Notiochyromya with tropical moist forests and Oroschyromya with less mesic, but montane, forest. A recent study of Aphaniosoma from central Asia (Ebejer 2006) has suggested for the first time that long cold winters and high altitude (2000-3000 m a.s.l.) do not represent a barrier to a diverse and rich fauna of Chyromyidae. Much still remains to be learnt regarding the ecology of this diverse family on a worldwide basis.

MATERIAL AND METHODS

The material used in this study was borrowed from several institutions, where the types are deposited. A list of institutional codens used in the text is provided below, with the names of respective curators being noted in parenthesis:

BMNH--Natural History Museum, London, UK (N. Wyatt);

CUMZ--University Museum of Zoology, Cambridge, UK (W. Foster);

MZH--Zoological Museum, Finnish Museum of Natural History, Helsinki, Finland (P. Vilkamaa);

FBUB--Biological Collection, Universitat Bielefeld, Bielefeld, Germany (M. von Tschirnhaus);

MHNG--Museum d'Histoire Naturelle, Geneva, Switzerland (B. Merz);

MJE--M.J. Ebejer, personal collection, Cowbridge, UK;

MZLU--Museum of Zoology, Lund University, Lund, Sweden (R. Danielsson);

NMNW--National Museum of Namibia, Windhoek, Namibia (E. Marais);

NMSA--Natal Museum, Pietermaritzburg, KwaZulu-Natal, South Africa (M. Mostovski);

NMWC--National Museum and Gallery of Wales, Cardiff, UK (J. Deeming);

OXUM--Hope Entomological Collections, Oxford University Museum of Natural History, Oxford, UK (D. Mann);

TAUI--Tel Aviv University, Tel Aviv, Israel (A. Freidberg);

ZMHB--Museum fur Naturkunde der Humboldt-Universitat, Berlin, Germany (J. Ziegler);

ZMUC--Zoological Museum, University of Copenhagen, Denmark (J. Pedersen);

ZSMC--Zoologische Staatssammlung, Munich, Germany (M. Kotrba).

Specimen data are given as they appear on the labels, except in the case of South African provinces, which are listed as current provincial names; where older names are on the label, these are given in parenthesis after the modern names. Specimen label data are listed in alphabetical order according to country, and are grouped in chronological order within each country. The mode of collection is stated, where known. Many specimens have been dry mounted and either pinned on minutens or mounted on card points. Other specimens are preserved in alcohol. The postabdomen is preserved with the remainder of the specimen in glycerine inside a small sealed plastic tube mounted on a pin, where a preparation of the postabdomen has been made from a specimen preserved in alcohol. In the case of dry material, the postabdomen is similarly preserved, and the plastic tube is pinned beneath the source specimen.

Measurements were made from the head (antenna excluded) to the apex of the abdomen; the wing was measured from its insertion into the thorax to the apex, the point where vein [R.sub.4+5] meets the costal vein. Measurements are only a guide. Some specimens shrivel more than others when dry and some expand more than others in alcohol. Furthermore, individuals within a species can vary by as much as 25 % in length (pers. observ.). The descriptions and the measurements are based on the holotype and a female paratype. In most cases, the illustrations of the male postabdomens are also based on the holotype.

The postabdomen was macerated in 10% potassium hydroxide, rinsed in water and alcohol and preserved in glycerine. Drawings were made freehand and with the specimen suspended in glycerine on a cavity slide or watch glass. It was orientated to allow view from the left lateral side, but it was frequently rotated and adjusted to allow better appreciation of the three-dimensional detail of the structures and their articulation. In many cases of male specimens, the view from below or behind was so complicated with overlapping pale structures that it was impossible to draw the composite structures clearly and reliably. For this reason, not many figures are given from these angles. However, where a particular structure such as a surstylus or a pregonite appeared very different from these angles, the structure was illustrated from both views. In a few instances, additional illustrations are given of one or both sexes of species previously described, where it is thought that this will clarify their structures and aid recognition.

Abbreviations used:

acrs--acrostichal

bac scl--bacilliform sclerite

basiph--basiphallus

cerc--cercus, cerci

dc--dorsocentral

distiph--distiphallus

ej apd--ejaculatory apodeme

ep--epandrium

epiph--epiphallus, epiphallic

fr--frons, frontal

hu--humeral

hyp--hypandrium

hypr--hypoproct

ia--intra-alar

ihu--intrahumeral

mtn--metanotum

ntpl--notopleuron, notopleural

oc--ocellus, ocellar

ocp--occiput, occipital

orb--orbital

pa--postalar

ph--phallus

ph apd--phallapodeme

posthu--posthumeral

post ia--posterior intra-alar

pprn--postpronotal lobe

pra--pre-alar

prg--pregonite

prpl--propleuron, propleural

prscut--prescutellar

prsut--presutural

psg--postgonite

pvt--postvertical

s--spermatheca(e)

sa--supra-alar

scut--scutellum, scutellar

st--sternite

surs--surstylus

tg--tergite

vt--vertical

vte--external vertical

vti--internal vertival

CLASSIFICATION

The systematic position of the Chyromyidae Hendel, 1916 remains somewhat unclear. D.K. McAlpine (1985) included the following families in the Heleomyzidae: Borboropsidae, Chiropteromyzidae, Cnemospathidae, Heteromyzidae, Notomyzidae, Rhinotoridae and Trixoscelididae, but excluded Chyromyidae and Sphaeroceridae although he accepted that these two families were closely related to the Heleomyzidae. J.F. McAlpine (1989) categorized all these families in the Sphaeroceroidea. Most recently, D.K. McAlpine (2007) categorized the Sphaeroceridae and Heleomyzidae into one family, the Heteromyzidae. He excluded the Chyromyidae on the grounds, that there remain several distinct morphological characters too far removed from his proposed groundplan of his concept of the Heteromyzidae. I concur with this view.

When studying Chyromyidae, especially from Africa, several species did not fit well into any currently accepted genus. The inevitable conclusion is either that all genera except Aphaniosoma are sunk as synonyms of Chyromya, or that new genera are erected to accommodate the additional species. The latter option is preferred for a number of reasons. There are many stable characters shared by groups of species (most of which are still undescribed) outside the Afrotropical Region. These characters were not given much importance or were not appreciated by previous authors. There also appears to be good correlation between the genera as proposed in this study and the type of habitat where their species are likely to occur. An improved classification at generic level may bring us closer to understanding the phylogenetic relationships within this family. When taking all the characters together it also becomes apparent that the differences between Aphaniosoma s. l. and the other genera are so substantial and fundamental that I consider there to be ample justification in placing them into two separate subfamilies. This proposal is treated below.

TAXONOMY

The nomenclature of somatic characters and chaetotaxy follows Sinclair (2000) and Ebejer (2006); for the female postabdomen see Kotrba (2000). The most recent comprehensive description of the family is given in the Manual of Palaearctic Diptera (Wheeler 1998). Wheeler's description of the family draws on published information available at the time. He accepted four genera, namely: Chyromya Robineau-Desvoidy, 1830, Gymnochiromyia Hendel, 1933, Somatiosoma Frey, 1945 and Aphaniosoma Becker, 1903. With the exception of Somatiosoma, the original descriptions were based on the Palaearctic species and in all of them, few characters were used. Reconsideration of relationships has required a review of several characters previously assumed to hold true across the family and others that were overlooked or underemphasized. These are described below.

The eye has enlarged facets at the extreme anterior angle near the antennae. The smallest facets are at the posterior extremity of the eye. In the intermediate area, facets diminish in size from anterior to posterior in a smooth gradation and there is no top to bottom demarcation line. All species have iridescent eyes, generally bright green, but this may vary from purple to reddish brown depending on the light and if the eye is wet. The ocelli are universally set in a small equilateral triangle on the vertex, and all species have a pair of proclinate, usually divergent, oc setae (or setulae) more or less in the middle of the oc triangle. In a few Aphaniosoma species these setae may be parallel.

The antenna (Fig. 1) exhibits little, but important, variation across the family. The two-segmented arista of Aphaniosoma was recognised as such only recently (McAlpine 2002). However, it is not two-segmented in all Aphaniosominae: in the new genus Krifomyia, all three segments are distinct. It is three-segmented in all Chyromyinae. The third antennal segment is round in almost all species (except for small indentations where it articulates with the arista and the second segment). In a few, it is slightly reniform.

At first sight, the wing (Figs 2, 3) appears uniform throughout the family, but microscopic examination under high magnification reveals a number of important characters. The hu crossvein varies from a small thin translucent vein (little more than a fold) to a broad thick set vein joining the costa at a point that is also thickened (e.g., Krifomyia). Just distal to this, the costa may be complete, weakened or broken. It is always broken in Aphaniosominae, but variably so in the Chyromyinae, where even within one genus there appears to be variation among species. The costa does not end abruptly at the wing apex, but rather tapers away after [R.sub.4+5], thus ending either some distance before or just after [M.sub.1+2]. The anterior margin of the costa is always setulose, usually densely so, but mixed in among these fine setulae are dark spine-like setulae that are usually of a similar length to the fine setulae though occasionally longer and set at variable distances from each other. They occur from the point where [R.sub.1] meets the costa to where [R.sub.2+3] ends on the costa. Within the family, they are found in most species of Chyromyinae, where on the dorsal aspect of the costa in the same sector there is also a small number of similar spine-like setulae set at wide intervals from each other. These are absent in the Aphaniosominae. Krifomyia has only pale, close set, evenly spaced, spinose setulae along the anterior margin. The long veins, [R.sub.4+5] and [M.sub.1+2], converge or diverge to a small but consistent degree that is a reliable character for separating some genera. The discal cell may or may not reach the middle of the wing, measured from base to apex, and it may be almost as wide as the cell formed between the R and M veins (the latter measured at its widest). Thus, the discal cell is short and narrow in the Aphaniosominae, whereas in the Chyromyinae it is broad and short (especially in Notiochyromya gen. n.) or narrow but long (Chyromya). The wing membrane is hyaline in the vast majority of species, and is uniformly microtrichose.

[FIGURE 1 OMITTED]

[FIGURE 2 OMITTED]

The interpretation of some thoracic setae can be difficult and may benefit from a brief description. A seta (or setula) is inserted at the anterior margin of the scutum between the most anterior dc and the anterior border of the pprn lobe. I call this the ihu seta, and it is quite distinct from the posthu. In Aphaniosoma s. str. it is incurved. It is absent in the Chyromyinae. The posthu seta (absent in Krifomyia) may be confused with the prsut ia. However, it is inserted more lateral to the ia when this is present. The pra seta is inserted dorsally in the depression just above the ntpl and just posterior to the transverse suture of the scutum. In some Chyromyinae, there may be a few setulae present in this area, but when compared to an adjacent seta such as the ntpl or the sa, it will be apparent that these setulae are by no means equivalent to a true pra. Furthermore, the number of these setulae is inconsistent within a species. The sa setae/setulae are in line with the pa, often well developed and distinct from the ia line of setae or setulae. There is no sa in Aphaniosoma. The post ia is midway between the pa on the posterior callus and the hindmost dc. When present, this may be a strong seta, but in any case it is longer than the strong prscut acrs setae. The anepisternal seta is inserted on the posterior margin of the anepisternum, very near the suture between this sclerite and the anepimeron. In the Aphaniosominae, it is just within the upper one third of the vertical posterior margin of the anepisternum, whereas in the Chyromyinae it is inserted almost exactly at the middle. There may be supplementary setae adjacent to it, but these are invariably much shorter than the main seta (these supplementary setae are present in all members of a species group within Aphaniosoma found in the Mediterranean--those whose males have projections on the hind trochanter). The prpl seta or setula is often minute, and is absent in all Chyromyinae.

[FIGURE 3 OMITTED]

Very little has been published on the female postabdomen of the Chyromyidae. Until now, little investigation has been done on the diversity of its form and consequently its usefulness in the taxonomy of species in this family. A recent study of Gymnochiromyia from southern Africa included an overview of this subject, and the female postabdomens of several species were illustrated (Ebejer 2008b).

The female abdomen in the Chyromyidae consists of seven easily recognised segments followed by the postabdomen, which consists of segments 8 to 10 and the cerc. In the Chyromyinae, segment 8 usually has a tg, which may be divided, and a st, which is always divided into a pair of distinct ventral or ventrolateral sclerites each bearing a small number of setae. These sclerites are useful in species diagnosis because their shape and the number and placement of their setae show remarkable consistency. Posterior to these sclerites is the genital opening, whose margins may be simple as in Chyromya, Gymnochiromyia, Notiochyromya and Oroschyromya, or extended into membranous lobes as in Somatiosoma. Posterior to this lies a small dorsal structure that is variously shaped, sclerotized and setulose. From its location, I take this to be the subanal plate but, as it is almost membranous in many species, I prefer the term hypoproct. This structure, too, appears to have a constant shape and setulosity within a species. In the Aphaniosominae, segment 8 is very close to the cerc. The dorsal sclerite usually is divided, and lies lateral to the cerc, attached to it or even apparently enclosing it. St 8 is less distinct in many species of this subfamily than it is in the Chyromyinae.

The paired spermathecae are very small (0.03-0.08 mm), round or nearly so, heavily sclerotized and pigmented in the Chyromyinae. They are proportionately larger (at least double the size) and of more varied shape in the Aphaniosominae. The spermathecal ducts are not visible at all in a majority of species (unless stained), although the base of the duct where it leaves the spermatheca is sometimes pigmented (e.g., N. sexspinosa (Lamb, 1914), Fig. 10). The darker internal structures appear to vary in shape depending on the degree of distortion produced by desiccation and/or subsequent preparation of the postabdomen. These internal structures are not reliable for separation of species in the Chyromyinae, but might prove to be useful in the Aphaniosominae because of greater diversity of form.

Two of the external characters that Becker (1903) applied to separate the genus Aphaniosoma from Chyromya also serve to separate the Aphaniosominae from the Chyromyinae. These are: (1) absence of an inclinate lower orbital (2) a concave ocp. The other characters he provided are variable in the subfamily Aphaniosominae. In addition to the above, the Aphaniosominae have a more derived ground plan of the male postabdomen, the Chyromyinae having a more pleisiomorphic ground plan. There are also chaetotaxic characters not noted in earlier works. The main features that separate the two subfamilies are detailed in Table 1. Some of these features are explained in more detail as follows.

The structure of the male postabdomen is fundamentally different in these two taxa. In the Chyromyinae, the ep is typical of most acalyptrate Diptera, namely the terminal abdominal segments form a more or less spherical sclerite that encloses most of the hypopygial structures within it. Tergite 6, the pregenital tg, is largely unmodified. The hyp and ep appendages are barely visible from an inferior aspect. Furthermore, these appendages do not deviate markedly in shape between species. In the Aphaniosominae, not only is the ep reduced and frequently split dorsally, but also it is largely or completely enclosed within tg 6, leaving the hyp and the basiph appendages largely exposed and visible from the posterior aspect. The appendages are remarkably diverse in form, size and orientation. In addition to this, it is the norm in the Aphaniosominae to have remarkable development of the pregenital st and tg (segments 4, 5 and 6).

The female abdomen presents an interesting feature. In the Chyromyinae, the ova develop to a large size and result in a distended abdomen with a stretched cuticle through which each ovum may be seen clearly. Females are found very commonly in this condition. Conversely, in the Aphaniosominae, the distension is much less marked and the ova are poorly discernible. Furthermore, females with distended abdomens are rarely found. This reflects an important, albeit not understood, biological function. However, it is a character that also should be considered in the division into two subfamilies.

In the male, the distiph is generally symmetrical in the Aphaniosominae and usually asymmetrical in the Chyromyinae. Observation of numerous specimens of several species in water or alcohol revealed a range of inflation and eversion of the distiph. This allows a degree of interpretation of the mechanics that result in the folding or unfolding of the distiph, a character in which the two subfamilies appear to differ. In the Chyromyinae, the point of articulation of the distiph with the basiph moves ventrally and anteriorly, deflecting the apex of the distiph in an arc downwards and backwards relative to the long axis of the abdomen; the distiph itself does not alter its shape. In the vast majority of species of the Aphaniosominae, the point of articulation between the distiph and the basiph moves posteroventrally and the distiph inflates and unfolds, resulting in movment in an arc downwards and backwards relative to the long axis of the abdomen. Thus, the shape of the distiph can appear very different (indeed often much larger) when unfolded, from when it is folded. This, too, is a character I consider important in the classification of the two subfamilies.

When attempts are made to prepare the postabdomen for detailed anatomical examination, substantial technical difficulties are encountered because of the very small size of these flies, the pallor of their integument and the three-dimensional array of the hyp. Notwithstanding this, the main structures and their appendages can easily be compared between species and genera in the Chyromyinae, because of consistency in location and appearance. This is far from being the case in the Aphaniosominae, where the huge diversity of form of the basic structures and their appendages makes interpretation and comparison much more difficult.

Subfamily Chyromyinae Hendel, 1916

Genus Chyromya Robineau-Desvoidy, 1830

Chyromya: Robineau-Desvoidy 1830: 620.

Type species: Chyromya fenestratum Robineau-Desvoidy, 1830: 621 [= Musca flava L., 1758], by monotypy.

Diagnosis: Broadfr, parallel sides or sides only slightly convergent anteriorly; in profile, gena recessed relative to projecting fr, and head generally higher than long; eye round and ocp clearly convex whether viewed from above or in profile; ocp setae and/or setulae scattered over whole disc, sparing only strip from vertex to short distance above occipital foramen; scutum with setulae scattered among strong setae; acrs rows irregular, composed of similar setulae; prscut pair stronger; pra and post ia setae absent, instead there are setulae of similar length to those on rest of scutum; scut with additional marginal setae to usual two pairs (basal and subapical); wing long, with discal cell being longest in family, thus length of vein separating basal and discal cells at least 2.5 times as long as apical section of M-Cu; posterior crossvein at middle or beyond middle of wing when measured from hu crossvein to apex; femora, especially fore and hind pairs in males, often strongly swollen; apicoventral seta on mid tibia absent.

Distribution: Holarctic. No species that corresponds to the genus as defined here has yet been found in the Afrotropical Region. However, in the Canary Islands, and coastal regions of North Africa, the following Palaearctic species do occur and their distribution may extend further south: flava (L., 1758); intermedia Ebejer, 2001; and robusta Hendel, 1931. These are not treated further in this paper.

Ecology: Compared to other genera, Chyromya species are encountered more frequently in open broadleaved woodland, parks and gardens. In the warmer parts of temperate regions, population densities can be high, but usually not as high as populations of Aphaniosoma and Gymnochiromyia. There are more records of an association with bird and especially mammal nests and burrows in Chyromya than in other genera of this family.

Genus Gymnochiromyia Hendel, 1933

Gymnochiromyia: Hendel 1933: 43; Ebejer 2008b: 81.

Type species: Peletophila minima Becker, 1904: 133 (= Anthophilina flavella Zetterstedt, 1848), by original designation.

This genus was recently reviewed (Ebejer 2008b) and 14 new species were described, bringing to 15 the total number of confirmed species from the Afrotropical Region.

Diagnosis: Oval eyes lying horizontal or oblique; fr protruding beyond anterior eye margin and above antennae, visible in profile to greater or lesser extent; setae and setulae on scut absent except for usual basal and subapical pairs; pra and strong post ia setae absent; apicoventral seta on mid tibia absent; habitus of most species appearing more slender and less setulose than Oroschyromya and Notiochyromya, with which genera Gymnochiromyia could be confused.

Distribution: Afrotropical (Fig. 68), Holarctic.

Bionomics: Species of Gymnochiromyia appear to prefer vegetated dunes and drier, warmer areas within a generally temperate climatic region. In Europe, for example, at least two species, namely G. homobifida Carles-Tolra, 2001 and G. inermis (Collin, 1933), exhibit an affinity for open oak woodland (Ebejer, pers. observ.).

Genus Notiochyromya gen. n.

Type species: Notiochyromya tripunctata sp. n., here designated.

Etymology: From Greek notios (southern), referring to the occurrence of the majority of species of the genus south of the equator, and Chyromya. Gender feminine.

Diagnosis: fr measured at level of anterior oc narrower than 1/3 width of head, with margins strongly convergent towards lunule, inclination of fr more toward vertical than horizontal, thus maximum length of head when seen in profile closer to lower eye margin than upper, ocp flat, pra seta present, post ia and prsut dc setae absent; scut usually with additional marginal or discal setae (not setulae) or both; a short apicoventral seta usually present on mid tibia; head usually narrower than thorax; ep relatively small in comparison to remainder of abdomen (similar to Somatiosoma, but in contrast to Oroschyromya and Gymnochiromyia); thorax robust, covered with dense fine setulae over whole of scutum; strong prscut acrs (often 4 setae in one transverse row), dc, post ia and pa setae close to scut suture and usually brown or black; tg frequently with matt or shiny brown or black spots.

The autapomorphies that characterize this genus are: a smaller head, longer in lower half than above, always higher than long, narrow fr strongly sloping such that it is inclined much more towards the vertical than the horizontal; a distinct pra seta, broad prg and large ej apd. In other respects, the habitus of the fly and the appearance of the scutum are similar to Somatiosoma.

Description:

Head: Higher than long, also a little broader than long; ocp flat in profile or only slightly convex; fr narrow at vertex, not more than 0.3 width of head, and eyes strongly convergent; orb plate distinct throughout. Chaetotaxy: 3 strong orb, 2 hind orb reclinate, anterior inclinate, pvt distinct and crossed, 1 vti and 1 vte, postocular setulae distinct, generally short, more or less in one row, lower postgenal seta present or absent; mouthparts normal, palp rather broad, almost disc-shaped; antenna with third segment round and arista bare.

Thorax: Broader than head and robust relative to remainder of fly. Chaetotaxy: prpl setula absent, 1 strong postsutural dc, often with 1 shorter seta anterior to this, acrs not differentiated from other scutal setulae, between dc lines in 8-12 rows with 2-4 distinct prscut; 1-2 pprn, 1 posthu, 2 ntpl, 1 distinct pra behind transverse scutal suture; 1 sa and 1 long pa, 1 short post ia, 2-4 pairs of marginal scut setae; sometimes with setulae on disc; anepisternum with 1 strong seta directed backwards at middle of posterior margin, katepisternum with 1 strong seta at upper posterior corner, each with a variable number of short setulae in front; tuft of numerous, fine, long setulae at ventral aspect of katepisternum.

Wing: Hyaline, [R.sub.4+5] and [M.sub.1+2] parallel towards wing apex or very slightly convergent at tip; discal cell wide beyond middle, about 2-3 times as wide as anterior basal cell; costal setulae short with variable number of stouter and darker setulae along anterior edge; costa, just beyond hu crossvein, narrowed but without distinct break. Haltere pale.

Legs: Yellow with fine setulae scattered on all pairs, in addition, a few longer setae usually present posterodorsally on fore femur; mid tibial apicoventral seta present or absent, but not longer than diameter of tibia at apex; femora, especially middle and posterior, slightly dilated; hind trochanter and tarsomeres not modified.

Abdomen: More or less compressed dorsoventrally; usually short but densely setulose, with longer setae along hind margin and lateral aspect of tg especially towards apex of abdomen; 6 visible tg in male and 7 in female, tg 6 normal; st sclerotized in both sexes, pollinose except for central part of st 2; pregenital st variably modified; female tg frequently with large brown to black shiny spots laterally.

Postabdomen: ep not usually as large as in other Chyromyinae; relatively large posteroventrally directed opening; cerc small, separated and poorly sclerotized with fine short setulae; hyp distinct and broad; ph apd broad and free from hyp for a short distance (cf. Gymnochiromyia); ej apd very large and well sclerotized; distiph complex as usual for the family, with sclerotized and membranous components;prg rather broad and flattened and variably sclerotized; psg of various forms in the species described.

Distribution: Afrotropical (Fig. 66); Pantropical.

Ecology: Species of Notiochyromya seem to prefer hot and wet (at least seasonally) environments. The genus is widespread in the tropics and subtropics of the Old World as well as the New World (New World species are undescribed), both on the continents and on islands. To date, most species are known from the Southern Hemisphere. Too little is known about their habits to make deductions on preference for vegetation cover, but by inference from data labels most appear to inhabit forests, or at least the edges of them. This includes forests encroaching on the seashore. N. sexspinosa was collected from entrances to caves in Nigeria (J.C. Deeming, pers. comm.).

Key to the Afrotropical species of Notiochyromya

[NB: The following key includes a number of undescribed species only known from females.]

Notiochyromya filigera sp. n. Fig. 4

Etymology: From the Latin filum (thread) and gerere (to bear), and refers to the long, thread-like distiphallus of this species.

Diagnosis: Pale yellow species with 3 pairs of marginal setae on scut; male with only a small central shiny spot on st 2; female with paired spots laterally on tg 2-7; head higher than long, entirely pale yellow; eyes slightly oval with long axis almost vertical; pleural setae and setulae on legs yellow; distiph with long apical filaments and broad curved surs, with posteriorly-directed flagelliform setae. Similar species: N. monticola sp. n.

Description:

Male.

Head: Entirely yellow, including oc triangle; ocelli black; fr narrow and long, at level of antennae 0.5 width that at level of anterior oc and 0.4 width of one eye viewed from in front; about 10 short pale setulae scattered over middle part and, on orbital plate, one brown setula in each of the intervening spaces between orb. ocp flat, in profile, barely visible behind eye; short postocular setulae irregularly in one row; isolated lower postgenal seta short. Gena broader near anterior buccal margin, narrow below eye, where at middle, about 0.3 height of eye and anteriorly about as broad as third antennal segment, yellow and with few pale setulae. Mouthparts yellow, palp round; setulae of buccal margin short. Face poorly sclerotized and depressed; median carina barely visible between bases of antennae. Antenna yellow, segment 3 about 0.35 length of horizontal diameter of eye, second segment with dorsal seta; arista brown, becoming pale at basal one third and with fine sparse pubescence. Chaetotaxy: 3 orb, anterior inclinate and as long as distance between orbits at this level, middle and posterior orb reclinate; pvt distinct and crossed, little more than half length of divergent ocellars; 1 vti and 1 vte, strong.

[FIGURE 4 OMITTED]

Thorax: Scutum and scut yellow and without pattern except for small brown spot basally on lateral scut margin, pleura paler, mtn yellow. Chaetotaxy: 1 pprn and 2 setulae, 1 posthu, 2 ntpl, 1 pra, 1 sa and 1 long pa, 1 long dc with a short seta in front of it about one third its length or less; acrs differentiated only as one prscut pair; scutum covered with numerous very short dark setulae in 8-10 rows between dc lines at level of transverse suture; scut with 3 pairs of marginals, middle pair shortest and situated just medial to a line joining basal and subapical setae; 1 anepisternal and 1 katepisternal, that on katepisternum at upper hind corner, that on anepisternum at middle of posterior margin; each with a few setulae in front.

Wing: Hyaline, veins all pale yellow; costal setulae brown to black with many stouter almost spinose setulae among them; dorsal aspect of costa with 3-6 spinose but very short setulae; costa beyond hu crossvein narrow but not distinctly broken; [R.sub.4+5] and [M.sub.1+2] run parallel to wing margin converging only in apical 1/4; distance between [R.sub.2+3] and [R.sub.4+5] about 0.7 that between [R.sub.4+5] and [M.sub.1+2]; discal cell broadest at level of anterior cross-vein; distance between crossveins 1.2 length of apical section of vein Cu. Haltere pale yellow.

Legs: Not modified except for very slightly thicker femora; numerous fine setulae scattered on all pairs of legs, in addition longer setae present on fore femur; mid tibial apicoventral seta short, a little less than diameter of tibia at apex; all setae and setulae pale yellow; claws and pulvilli normal.

Abdomen: Yellow, with darker yellow and shiny transverse bands on all tergites and dark brown spot on ventrolateral aspect of tg 2; setulae brownish yellow and on tg 4-6 laterally and along hind margin with longer setae; sternites sclerotized, yellow, st 2 with small shiny spot at middle; st 5 with pair of posterior lobes broad at their apex with a fringe of fine setulae, long seta on lateral margin.

Postabdomen: cerc very small with few minute setulae; ep more or less hemispherical, surs broad, strongly curved and with 5 distinct broad setae along posterior edge at apex; prg broad with row of setae along middle of lateral surface, psg narrow, long, almost straight; ej apd large, bilobed sclerotized and of distinct shape; ph apd broad at base and distinctly curved towards hyp; distiph with sclerotized and membranous components, with very distinctive flagellate apex.

Female.

Similar to male, generally darker colouration of vestiture, and more defined and darker brown bands on abdominal tg with black or dark brown spot on lateral aspect of tg 2-7. Postabdomen: very similar to monticola (Fig. 8), but st 8 with one row of setae along middle third of sclerite, inserted parallel to long axis and each curved medially; cerc small, similar in size to hypr; first section of spermathecal duct thinly sclerotized. Length: [male] body 1.5 mm, wing 1.5 mm; [female] body 1.7 mm, wing 1.6 mm.

Holotype: [male] MAURITIUS: Wolmar, 1-2 km S [20[degrees]18'S:57[degrees]22'E], 21.v.2000, J.W. Ismay, coast roadside (OXUM).

Paratypes: 1 [female] same data as holotype (OXUM). KENYA: 1 [male] Hunter's Lodge, nr Kiboko, 02[degrees]14'S:37[degrees]43'E, 8-9.viii.2003, A. Freidberg (TAUI); 29 Rt B8, nr Takaungu, 50 km N of Mombasa, 03[degrees]42'S:39[degrees]49'E, 12.viii.2003, A. Freidberg (TAUI, NMWC); 2 [male] Simba, 02[degrees]09'S:37[degrees]35'E, 15.ix.2005, A. Freidberg (TAUI, NMWC). SOUTH AFRICA: KwaZulu-Natal: 1 [female] Pietermaritzburg, 15.ix.1976, R.M. Miller (NMSA). YEMEN: 1 [male] 1 [female] Ta'izz, 5.i-2.ii.1998, A. van Harten & M. Mahyoub (NMWC).

Notiochyromya lucida sp. n. Fig. 5

Etymology: From Latin lucida (shiny), and refers to the shiny, weakly pruinose scutum of this species.

Diagnosis: A small orange-yellow species with a relatively large third antennal segment; scutum very sparsely pruinose, scutal setulae between dc rows at level of tranverse suture in 10 rows, scut with 4 pairs of marginals and abdomen without any markings.

Description:

Male.

Head: All yellow, including oc triangle; fr narrowed anteriorly, at level of antennae 0.6 width that at level of anterior oc and 0.6 width of one eye viewed from in front; covered with numerous minute pale setulae. Gena narrow, about 0.3 height of eye, yellow and with pale setulae. ocp yellow, in profile narrowly visible behind entire eye margin; with short postocular setulae irregularly in one row; isolated lower post-genal seta absent. Mouthparts small, yellow, palp short and round, vibrissal setulae of buccal margin longer, longest a little longer than anterior orbital. Face poorly sclerotized and depressed; median carina absent. Antenna yellow; second segment paler than third, with distinct short dark seta dorsally; third segment large and round, about 0.35 length of horizontal diameter of eye, finely pubescent; hairs shorter than diameter of arista at base; arista black almost throughout, yellow only at base and bare. Chaetotaxy: 3 strong orb, anterior strongly inclinate and longer than fr is wide at this level, middle orb closer to anterior than to posterior; oc short, divergent and shorter than pvt; 1 vti and 1 vte both strong.

[FIGURE 5 OMITTED]

Thorax: Yellow with somewhat darker dc and ia lines; ntpl contrasting very pale yellow; scut, mtn and pleura all yellow; scut flat on disc, lateral marginals about half length of subapicals, with shorter setae between marginals, but not on disc. Chaetotaxy: 1 pprn, 1 pra, 1 sa, 1 pa, 2 ntpl, 1 strong postsutural dc and another in front of this about one third its size; acrs undifferentiated; setulae on scutum at level of transverse suture in 8 irregular rows between dc lines; pleural setae not seen because of pin.

Wing: Hyaline, veins all pale yellow; [R.sub.4+5] and [M.sub.1+2] run parallel to wing margin converging only in apical 1/4; distance between [R.sub.2+3] and [R.sub.4+5] about 0.7 that between [R.sub.4+5] and [M.sub.1+2]; discal cell broadest at level of anterior crossvein; distance between crossveins 0.7 length of apical section of vein Cu. Haltere pale yellow.

Legs: Not modified, except for slightly thicker femora; generally fine pale setulae scattered on all pairs of legs, in addition about 6 long setae present on posterodorsal aspect of fore femur; mid tibial apicoventral seta almost as long as diameter of tibia at apex, yellow; claws and pulvilli normal; hind trochanter normal.

Abdomen: All yellow and without pattern of spots or bands; setae short; st 6 with a long seta laterally; tg 6 narrow and mostly covered by ep.

Postabdomen: ep large and yellow with a short surs projecting antero-ventrally; ej apd very large, umbrella-shaped and reaching far forward, ph apd long and broad; prg trapezoidal, psg not identified, surs narrow, curved at extreme apex.

Female. Unknown.

Length: [male] body 1.6 mm, wing 1.6 mm.

Holotype: [male] TANZANIA: E Usambara Mts, Amam Research Station [05[degrees]06'S:38[degrees]38'E], alt. 900 m, 1927.vi.1974, D. Hollis (BMNH).

Notiochyromya monticola sp. n. Figs 6, 7

Etymology: From the Latin mons (mountain) and incola (inhabitant), and refers to the high altitudes at which this species occurs.

Diagnosis: A species with an orange-brown head, yellow thorax with scutum a deeper yellow to pale brown, and pale brown to yellow abdomen; mtn yellow and all setae and setulae black; male with st 2 mostly shining and st 6 with two backwardly projecting lobes and strong lateral setae; scut with 3 pairs of marginals; distiph with apical filaments, psg narrow with normal setae. Similar species: N. filigera sp. n.

[FIGURE 6 OMITTED]

Description:

Male.

Head: Higher than long, deep orange yellow including oc triangle; fr narrowed anteriorly: at level of antennae 0.2x width of head and 0.5x width of that at level of anterior oc, with several minute dark setulae across middle; lunule high, about equal to length of antennal segment 3; ocp brown except for upper 1/3 of postocular margin and behind vertex, which are yellow; ocp in profile narrowly visible behind eye margin in lower half; short postocular setulae in one row; eye almost round, just a little higher than long and anterior facets about twice size of posterior facets; mouthparts small, yellow, palp short and round, vibrissal setulae of buccal margin only a little longer that genal setulae; face small, poorly sclerotized and depressed; median carina absent. Gena about 0.3x height of eye at middle, yellow and with numerous brown setulae, isolated lower postgenal seta short but distinct; antenna small and yellow; second segment paler than third, with distinct short dark seta dorsally; third segment about 0.25x length of horizontal diameter of eye, finely pubescent: hairs shorter than diameter of arista at base; arista black almost throughout, yellow only at base and sparsely but at regular intervals with minute pubescence. Chaetotaxy: 3 strong orb, anterior strongly inclinate and as long as fr is wide at this level; oc long, erect, slightly divergent, pvt distinct and crossed; 1 vti and 1 vte, both strong.

Thorax: Yellow with somewhat darker yellow to pale brown scutum; ntpl contrasting pale yellow; scut, mtn and pleura all yellow. Chaetotaxy: all setae and setulae black or at least dark brown, 1 pprn with 2 adjacent setulae, 1 posthu, 1 pra, 1 sa, 1 pa, 1 short post ia, 2 ntpl, 1 strong postsutural dc and another in front of this about 1/3 its size; acrs undifferentiated; setulae on scutum at level of transverse suture in 8 irregular rows between dc lines; prscut pair strong, about as long as 0.5x length of hind dc, 1 anepisternal in upper 1/3 and 1 katepisternal at upper posterior corner with several short dark setulae in front of each; scut with 3 pairs of marginals, middle pair shortest and set just medial to line joining basal and subapical pairs.

Wing: Hyaline, veins yellow; anterior costal setulae black, no dorsal setulae present; distance between [R.sub.2+3] and [R.sub.4+5] about 0.6x that between [R.sub.4+5] and [M.sub.1+2]; apical section of Cu about 1.5x length of posterior crossvein; distance between crossveins about equal to length of apical part of Cu. Haltere yellow.

[FIGURE 7 OMITTED]

Legs: Not modified; fine dark setulae scattered on all pairs of legs; mid tibial apicoventral seta half as long as diameter of tibia at apex, dark brown; claws black.

Abdomen: Yellow to brown with numerous dark setulae on dorsum and laterally and on hind margin of tg 4-6 with several longer setae; large shiny black spot ventro-laterally on tg 2; st 2 also dark and shiny except for narrow brown dusted border, st 5 with a pair of lobes directed backwards and long setae laterally; tg 6 almost as broad as tg 5 and completely separated from ep.

Postabdomen: ep large, hemispherical and brownish yellow with a large surs projecting postero-ventrally and setulose on hind margin and curved at apex; ej apd very large and bilobed, ph apd long and broad; prg trapezoidal, with apex directed slightly forward and setulose, psg small and pointed, distiph with flagellum at apex, cerc without special modifications.

Female.

As in male, but abdomen with paired large shiny black spots laterally on each tg and along midline with a variably developed darkening. Postabdomen: Sclerotized sternal plates of segment 8 having long setae on posterior part; hypr small, poorly sclerotized and weakly setulose, similar in size to small cerc; spermathecal duct thinly sclerotized in first part from s.

Length: [male] body 1.9 mm, wing 2.2 mm; [female] body 2.0 mm, wing 2.3 mm.

Variation: Remarkably little in both sexes; the intensity and extent of dark areas varies a little as does the colour of the setae from black to brown; scut yellow, but in a few specimens with very small dark spot at base of lateral margin.

Holotype: [male] ETHIOPIA: Shewa, Debre Tsige, 09[degrees]39'N:38[degrees]49'E, 2660 m, 28.ix.2005, A. Freidberg (TAUI).

Paratypes: 5 [male] 4 [female] same data as holotype (TAUI); 1 [male] 1 [female] same data (BMNH); 2 [male] 2 [female] same data (NMWC); 2 [male] 1 [female] same data (NMSA); 2 [female] Tigray, Axum, 2220 m, 14[degrees]08'N:38[degrees]43'E, 4-5.x.2005, A. Freidberg (TAUI). SOUTH AFRICA: Western Cape: 1 [female] Wilderness National Park, 17 km SE George, 35[degrees]59'S:22[degrees]39'E, 14.x.1994, R. Danielsson (MZLU).

Notiochyromya sexspinosa (Lamb, 1914), comb. n. Chiromyia sexspinosa: Lamb 1914: 355.

Figs 8a, 9b, 10

[FIGURE 8 OMITTED]

Diagnosis: A yellow species with abdomen (females) marked with dark spots: 1 large pair on tg 2, smaller pair on each of tg 3-6; tg 3-5 dorsally at middle sometimes with brown ill-defined spot; scut with 3 pairs of marginal setae. Postabdomen with very small cerc and hypr, the latter with about 6 microtrichia; s not uniformly black and with sclerotized first part of duct very short. The specimens from Niger Province listed below are rather pale with the spot on tg 2 light brown and the brown bands dorsally on tg absent.

Type material examined: SEYCHELLES: [female] (holotype) 'Mahe 08-9, Seychelles Exp. / Prof. J.S. Gardiner' (BMNH); 3 [female] (paratypes) same data (1 BMNH, 2 CUMZ).

Other material examined: GHANA: 1 [female] Accra, 1921, J.W. Scott Macfie, laboratory windows (BMNH). NAMIBIA: 1 [female] Rundu District, 20 km E Rundu, 17[degrees]55'46"S:19[degrees]58'43"E, 17-18.x.1999, A.H. Kirk- Spriggs, T. Pape & W. Hauwanga, Malaise trap (NMNW). NIGERIA: 1 [female] Zaria, Samaru, 9.iii.1969, J.C. Deeming (NMWC); 2 [female] Zaria, Samaru, viii.1967, [no collector], mercury vapour light trap (BMNH); 89 Niger Province, nr Mokwa, 2.v.1973, J.C. Deeming, at entrance to bat cave (NMWC).

[FIGURE 9 OMITTED]

[FIGURE 10 OMITTED]

Distribution: Ghana, Namibia, Nigeria, Seychelles.

Remarks. Lamb (1914) wrote that he had four males. This is a surprising error as in fact they are all females with the ova developed to an advanced stage. They are almost identical to each other. In three of the specimens, the dark spots on the abdomen are brown and shiny rather than black. Lamb's description is not detailed enough to allow the identification and reliable separation of sexspinosa from the undescribed sp. C only on the basis of females (see below).

Notiochyromya tripunctata sp. n. Figs 8b, 9a, 11

Etymology: From the Latin tri- (three-) and punctata (spotted), and refers to three sets of spots on the tg.

Diagnosis: Relatively large yellow species with very narrow gena and characteristic dark pattern of spots on tg; scut with disc flatter than usual and with 2 pairs of marginal setae; most setae and setulae dark brown to black.

Description:

Male.

Head: All yellow, including oc triangle; fr narrowed anteriorly: at level of antennae 0.6 width that at level of anterior oc and 0.4x width of one eye viewed from in front. ocp yellow, in profile barely visible behind eye; with short postocular setulae irregularly in one row; isolated lower postgenal seta short. Gena very narrow, about 0.2x height of eye at middle, yellow and with pale setulae. Mouthparts small, all yellow, palp round and short, vibrissal seta as long as anterior orb, other setulae of buccal margin short. Face poorly sclerotized and depressed, median carina absent. Antenna yellow, second segment paler than third, with short dark seta dorsally; third segment small and round about 0.25x length of horizontal diameter of eye, finely pubescent hairs shorter than diameter of arista at base; arista black almost throughout and completely bare. Chaetotaxy: 3 strong orb, the anterior strongly inclinate, middle and posterior orb reclinate;pvt minute, barely visible; 1 vti and 1 vte both strong; oc short and strongly lateroclinate; numerous fine short setulae over most of fr, including on intervening spaces between orb setae.

Thorax: Yellow with a pair of light brown stripes in midline of scutum, between dc and ia lines, and posteriorly along sa line; a small brown patch onpprn. Scutum very flat on disc, bare except for 2 pairs of marginals, and with a small brown spot at base ventrolaterally; mtn brownish-yellow; pleura all yellow and paler than disc of scut. Chaetotaxy: 1 pprn and 3 setulae, 1 posthu, 1 pra, 1 sa, 1 pa, 2 ntpl, 1 strong dc and another in front of this about half its size; acrs undifferentiated apart from prscut pair which is a little longer than anterior dc; very short and very numerous setulae over whole of scutum, about 10-12 rows between dc lines at level of transverse suture; anepisternum with numerous scattered setulae in posterior half, 1 strong anepisternal seta directed horizontally backwards from middle of posterior margin of sclerite; 1 katepisternal at upper hind corner of katepisternum.

Wing: Hyaline, veins all pale yellow; costal setulae brown to black with many stouter almost spinose setulae among them; dorsal aspect of costa without spinose setulae; costa beyond hu crossvein narrow but not distinctly broken; [R.sub.4+5] and [M.sub.1+2] run parallel to wing margin converging only in apical 1/4; distance between [R.sub.2+3] and [R.sub.4+5] about 0.8 that between [R.sub.4+5] and [M.sub.1+2]; discal cell broadest at level of anterior crossvein; distance between crossveins about equal to length of apical section of vein Cu. Haltere pale yellow.

Legs: Not modified except for slightly thicker femora; generally fine pale setulae scattered on all pairs of legs, in addition about 6 longer setae present on posterodorsal aspect of fore femur; mid tibial apicoventral seta half diameter of tibia at apex, brown; all tarsomeres with several distinctly longer setulae on dorsal aspect, claws and pulvilli normal.

Abdomen: Relatively long and narrow, somewhat tapering apically; tg with a pattern of brown spots and bands at base; midline spots on tg 3, 4 and 5, slightly shining and almost black; setulae on discs of tg short, numerous and dark, longest less than half as long as tg; st all yellow.

[FIGURE 11 OMITTED]

Postabdomen: ep with distinct dark spot at middle; small and with very short setulae; hyp broad and fused with anterior lower margin of ep;ph apd small, lying within curve of hyp; ej apd very small; prg short with rounded apex, surs short, curved inwards, psg not identified, basiph cuboid; distiph broad mostly membranous.

Female.

Similar to male, but no midline spots or stripe and lateral spots small. Postabdomen not dissected.

Length: [male] and [female] body 2.7 mm, wing 2.3 mm.

Holotype: [male] MAURITIUS: Beline, 28.v.2000, J.W. Ismay, mangroves (OXUM).

Paratypes: 1 [male] same data as holotype (OXUM). SOUTH AFRICA: Eastern Cape: 1 [female] 5 km SW Grahamstown [33[degrees]16'S:26[degrees]29'E], 10.i.1984, D.J. Brothers (NMSA). YEMEN: 1 [female] Mukalia, vi.2001, A. van Harten & M. Hubaishan, light trap (NMWC).

Notiochyromya sp. A

A yellow species except for large black spots laterally on tg 3-6; antennal segment 3 broader than gena (a character state that distinguishes this species from congeners); mtn yellow and scutal setulae between dc line in 6-8 rows; scut with 6 marginal setae, but the basals are the shortest.

Material examined: NAMIBIA: 1 [female] Rundu District, 20 km E Rundu, 17[degrees]15'46"S:19[degrees]58'43"E, 17- 18.x.1999, A.H. Kirk-Spriggs, T. Pape & W. Hauwanga, Malaise trap (NMNW).

Notiochyromya sp. B

This is a relatively large bright yellow species, which also has all the vestiture pale yellow; the scut has 8 marginal setae, but no setulae on disc; mtn yellow; abdomen with a short longitudinal dark line at apex formed of a fusion of the midline spots on tg 6 and 7.

Material examined: NAMIBIA: 1 [female] Mahango Game Reserve, Thinderevu Omuramba, 18[degrees]15'S:21[degrees]40'E, 28.ii-13.iii.1992, M. Pusch & E. Marais; 1 [female] Ovambo, Onduri, 17[degrees]32'S:16[degrees]37'E, 14-26.i.1993, E. Marais, pitfall trap (in alcohol, NWMC); 2 [female] Ovambo, Onghwiya, 17[degrees]34'S:16[degrees]49'E, 14-26.i.1993, E. Marais, pitfall trap; 3 [female] Ovambo, Enyana, 17[degrees]37'S:17[degrees]25'E, 14-27.i.1993, E. Marais, pitfall trap; 3 [female] Kavango, Nangera, 17[degrees]37'S:18[degrees]08'E, 14-27.i.1993, E. Marais, pitfall trap; 1 [female] Kavango, 5 km NE Dikweya, 17[degrees]41'S:18[degrees]32'E, 14-27.i.1993, E. Marais, pitfall trap (all in alcohol, NMNW); 1 [female] Rundu District, Simanya Okavango R., 17[degrees]33'35"S:18[degrees]32'30"E, 23-24.i.1998, A.H. Kirk-Spriggs & E. Marais, Malaise traps, riverine forest; 29 Kaudom Game Park, 10 km W of Dussi, 18[degrees]48'32"S:20[degrees]43'57"E, 29-30.xii.1998, E. Marais, A.H. Kirk-Spriggs & D. Mann, Malaise traps; 3 [female] Rundu District, Hamoye Nat. forest, 18[degrees]12'S:19[degrees]43'E, 5-8.iii.1999, E. Marais, Malaise trap; 19 Gobabis District, Somerkoms 521, 22[degrees]01'59"S:19[degrees]57'22"E, 6-8.ii.2001, A.H. Kirk-Spriggs & E. Marais, Malaise trap (all dry-pinned, NMNW).

Notiochyromya sp. C

A yellow species with completely dark mtn and paired spots on all tg, spots on tg 1 and 2 merge to form a large oval patch, spots from tg 3 to 7 gradually increasing in size towards apex of abdomen; scut with small brown spot at base ventrolaterally and short setae on disc apart from 6-8 additional marginal setae, which alternate in size, the basal shortest; scutal setulae between dc lines in 10 rows. This species is similar to sexspinosa. It differs in the number of scut setae and the progressively larger spots on the abdomen from base to apex.

Material examined: NAMIBIA: 89 Rehoboth District, Garles Oos 489, 23[degrees]54'S:16[degrees]33'E, 9.ii-23.iii.1993, E. Marais, pitfall trap (all in alcohol, NMNW); 1 [female] Tsumkwe District, Nama, 19[degrees]54.34'S:20[degrees]44.08'E, 2022.xii.1998, A.H. Kirk-Spriggs, E. Marais & D. Mann, Malaise traps (dry-pinned, NMNW).

Notiochyromya sp. D

These specimens belong to a yellow species with the scut having no additional marginals and no short discal setae but, as in filigera and monticola, there is a pair of setae on the disc just medial and posterior to the subapical pair; scutal setulae between dc lines in 10 rows; mtn dark brown; abdomen with segments 3-7 having paired brown spots laterally. It is not included in the above key for lack of easily defined characters.

Material examined: NAMIBIA: 1 [female] Windhoek, Hoffnung farm, lucerne fields, 7.ii.1972, British Museum Southern African Expedition 1972 (dry-pinned, BMNH). ZIMBABWE: 1 [female] Zambezi, Rutometje-Res. St. RM2, 16[degrees]10'S:29[degrees]25'E, vii.1988, J. Weyrich (in alcohol, ZSMC).

Genus Oroschyromya gen. n.

Type species: Oroschyromyaperuncinata sp. n., here designated.

Etymology: From the Greek oros (mountain), indicating the occurrence of the majority of species of the genus at high altitudes, and Chyromya, denoting the affinity to this genus.

Diagnosis: Head broader than thorax; fr narrow with moderate to strongly converging margins; eye oval, lying oblique in profile; ocp slightly convex with a few setulae on disc; femora long and slender; a well-developed post ia present; scut without additional marginals or setulae on disc; apicoventral seta on mid tibia absent; ep large, more or less rectangular and sits vertically relative to the long axis of the abdomen; cerc modified and prg large, heavily sclerotized, conical to pyramidal.

The autapomorphies that characterize this genus include a strong post ia seta, very large vertically elongated ep, an intermediate sclerite between the posterior edge of hyp and prg, large mobile surs and prg, and modified cerc. In the female, segments 6 and 7 usually membranous dorsally, therefore appearing divided, with heavily sclerotized lateral sclerites that are also strongly setose, giving them the appearance of a second pair of cerc. In other respects, scutum and scut appear similar to those in Gymnochiromyia, but in this genus the head is not so broad, the post ia is absent and the male and female postabdomens present different character states.

Description:

Head: Broader than long; ocp flat in profile or only slightly convex, somewhat concave when viewed from above; fr broad at vertex and eyes strongly convergent; orbital plate distinct. Chaetotaxy: 3 strong orb more or less reclinate, but also lateroclinate, anterior orb inclinate or reclinate; pvt distinct and crossed; strong vti and vte; postocular setulae distinct, especially behind vt, others short, more or less in one row, lower postgenal seta present; mouthparts normal, palp round or almost round.

Thorax: Elongated, narrower than width of head. Chaetotaxy: prpl setula absent, 1 or 2 strong posterior dc, sometimes with 2-4 short dc anterior to these, scutal setulae between dc lines in 4-8 irregular rows with one short, but distinct prscut pair; 1-2 pprn, 1 posthu, 2 ntpl, 1 sa and 1 long pa, 1 post ia, absent pra; 2 pairs of marginal scut setae: one subapical and one basal, no setulae on margin or on disc; anepisternum with 1 strong seta at middle of posterior margin directed backwards, often with another shorter seta above, katepisternum with 1 or 2 strong setae at upper posterior corner; tuft of numerous, fine, long setulae at ventral aspect of katepisternum.

Wing: Hyaline or faintly and diffusely infuscated, [R.sub.4+5] and [M.sub.1+2] parallel to wing apex or very slightly convergent; vein closing anal cell often with a minute stump vein at middle; hu break present or absent, in which case a distinct weakening apparent, costal setulae with minute spine-like setulae interspersed among them along anterior margin of costal vein between [R.sub.1] and [R.sub.2+3], several similar short spine-like setulae present at irregular distances on dorsal aspect of costa.

Legs: Fine setulae scattered on all pairs, in addition longer setae present on fore femur; mid tibial apicoventral seta absent, femora not or hardly dilated, hind trochanter and tarsomeres not modified. One species has additional setal characters.

Abdomen: Variably compressed laterally; 6 visible tg, tg 6 narrow; st sclerotized, st 5 modified, st 6 often reduced to V-shaped sclerite.

Male postabdomen: ep well-developed, vertically elongated and variably compressed laterally with relatively large ventrally directed opening; cerc large sclerotized to a variable degree and usually with modified setae, either as 3-5 strong, but short spines in addition to fine setulae or longer and stronger setae than usual for family; hyp distinct with additional lateral sclerites between its posterolateral end and base of prg, ph apd long, narrow and free from hyp for a significant distance (cf. Chyromya and Somatiosoma), ej apd small, not recognisable (or not sclerotized) in some species; distiph complex as usual for the family, with sclerotized and membranous components;prg heavily sclerotized, more or less conical that is, more like a large spine than a flat sclerite, with strong setae, psg distinct and sometimes remarkably modified.

Female postabdomen: Segments 6-8 variously modified, usually with one or more segments having tg divided into large heavily sclerotized lateral sclerites with strong setae, hypr distinct, s relatively small and very deeply pigmented; cerc tending to be elongate.

Distribution: Afrotropical (Fig. 67).

Ecology: Oroschyromya is known only from Africa. The genus appears to favour wellvegetated habitats with a wide range of rainfall. All species but one are from high altitude (1200-3200 m). The single lowland (260 m) species (O. dubia (Lamb, 1914) from Mauritius and the Seychelles) is placed in this genus on the basis of strict character interpretation and postabdominal features of both sexes, but its general appearance is more like Notiochyromya or Gymnochiromyia.

Key to the species of Oroschyromya

Oroschyromya affinis sp. n. Figs 12, 13

Etymology: From Latin affinis (similar), and refers to the close affinities of this species with O. peruncinata sp. n.

Diagnosis: Pale yellow species with dark fifth tarsomeres; large hypopygium with complex structures easily visible externally; spinose, elongate, separated cerc; differs from sibling species, O. peruncinata sp. n., in details of postabdomen.

Description:

Male.

Head: Yellow, small black oc triangle; not quite twice as broad as long; fr strongly narrowed anteriorly: at level of antennae 0.4 width that at level of anterior oc, at vertex 1.4 width of eye; gena narrow in front, deeper behind and in profile, below middle of eye, about equal to height of eye; yellow and pale haired. ocp in profile visible behind eye and slightly convex; short postocular setulae in one irregular row; isolated lower postgenal seta present, but little longer than other setulae. Mouthparts small, all yellow, palp rather broad almost round; vibrissal setulae moderately developed. Face short, poorly sclerotized and depressed. Antenna yellow; second segment pale yellow with distinct short dark seta dorsally; third segment round, finely pubescent: hairs as long as diameter of arista at base; arista black, only at base of second segment and whole of first segment yellow, minutely pubescent. Chaetotaxy: 3 strong orb, all reclinate; pvt distinct and convergent; 1 vti and 1 vte strong; ocellars long and lateroclinate; no setulae across middle of fr.

Thorax: Uniform pale yellow colour throughout and somewhat elongated with dorsal aspect more flattened than is usual in this family. Chaetotaxy: prpl absent, 0+2 strong dc, the anterior shorter, scutal setulae in 6 irregular rows between dc lines, with one short, but distinct prscut pair; 3 or 4 irregular rows of setulae also between the dc and sa lines; 2 pprn, 1 posthu, 2 ntpl, 1 sa and 1 pa, 1 post ia; 2 pairs of marginal scut setae: one subapical and one basal, no setulae on margin or on disc; anepisternum with about 14 setulae at middle and 1 strong seta directed backwards at middle of posterior margin, katepisternum with about 6 setulae at middle and 1 strong seta at upper posterior corner and a tuft of numerous, fine, long setulae at ventral angle. All setae and setulae pale brown. Wing: Hyaline with pale yellow veins; discal cell widest at apex; distance between [R.sub.2+3] and [R.sub.4+5] about 0.6 that between [R.sub.4+5] and [M.sub.1+2]; distance between crossveins about 0.9 length of apical section of vein Cu. [R.sub.4+5] and [M.sub.1+2] parallel, converging only very slightly only towards wing apex. Haltere pale yellow, concolourous with thorax. Legs: Not modified; fine setulae scattered on all pairs of legs; in addition longer setae present on fore femur, but not as long as diameter of femur; mid tibial apicoventral seta absent; tarsomere 5 of mid and hind legs brown; claws black, pulvilli normal; hind trochanter normal.

[FIGURE 12 OMITTED]

Abdomen: Entirely yellow and only slightly compressed laterally towards apex; 5 visible tg, tg 6 very narrow and incorporated within and along anterior margin of ep; st sclerotized; st 5 with ventrally directed pair of narrow projections and long setae on sides of posterior margin. Short setae on disc of tg and some st, about 1/3 length of tg. Postabdomen: Outwardly almost identical to that in peruncinata (see Figs 29-31), ep well-developed and elongated dorsoventrally; cerc large with 3 strong, but short spines in addition to fine setulae, hyp distinct with short, poorly sclerotized flange directed towards base of abdomen, ph apd long and free from hyp, ej apd not recognisable (not sclerotised at all), prg large, heavily sclerotized, anterolaterally directed spine and psg in the form of a flat curved sclerite. distiph large with sclerotized and membranous components and asymmetrical at apex.

Female.

Similar to male, but with exceptionally strong setae on apex of abdomen and on lateral heavily sclerotized discoid-shaped plates of tg 6; strong setae and short setulae on apical margin of tg 5 missing from lateral third on each side. Postabdomen: tg 7 small, narrow and Y-shaped at apex; setulae on st 8 short and obscured from lateral view; hypr small, more or less semicircular and microtrichose.

[FIGURE 13 OMITTED]

Length: [male] body 2.0 mm, wing 1.7 mm, [female] body 1.9 mm, wing 2.0 mm.

Holotype: [male] YEMEN: Ta'izz [13[degrees]34'N:44[degrees]00'E], 3-24.1.1999, A. van Harten & M. Mahyoub (NMWC).

Paratypes: ETHIOPIA: 2 [female] Tigray, Axum, 14[degrees]08'N:38[degrees]43'E, 2220 m, 4-5.x.2005, A. Freidberg (TAUI). KENYA: 1 [male] S of Lake Naivasha, YMCA camp, 13.viii.1981, L. Froberg, meadow at shore (MZLU). YEMEN: 1 [female] Suq Bani Mansour, 28.viii-26.ix.2001, A. van Harten, Malaise trap (NMWC).

Note: A single female with the following data: NAMIBIA: 1 [female] Keetmanshoop District, Narubis nr Lowen R., 870 m, riverine forest, 20.ii.1974, M.E. Irwin (NMSA), may belong to this species, but as it has been found on the other side of the continent I hesitate to confirm its identity.

Oroschyromya bicolor sp. n. Figs 14, 15

Etymology: From Latin bi- (two-) and color (colour), and refers to the well-developed pale and dark contrasting colouration in both sexes.

Diagnosis: A smaller species than its congeners, with a pair of brown longitudinal stripes running from front of scutum on to scut as far as base of subapical setae; abdomen dark brown dorsally with contrasting yellow ep; tarsomere 5 of all legs brown.

Description:

Male.

Head: Yellow, broader that thorax, fr narrow, strongly converging towards front, at level of anterior oc about 0.35 width of head and at level of antennae 0.7 width of that at anterior oc; vti and vte on shiny pale brown spot; ocp yellow with postocular setulae in 2 rows, that nearest eye margin with setulae pointing downwards and outwards, that placed more on disc of ocp with setulae pointing inwards and upwards; eye elongate oval with anterior facets about 3x size of posterior facets; face flat, membranous and without any noticeable carina; gena pale yellow, about 0.8 height of eye at middle, with several fine very pale yellow setulae, postgenal seta very long, as long as anterior orb; mouthparts yellow, palp short oval, almost round; antenna yellow with central pale brown patch on external aspect of segment 3, which also has a distinct fringe of minute pale pubescence along anterior margin and is about 0.25 length of eye, second segment with long dorsal seta, arista with black third segment, which also has a sparse fine pubescence; 3 orb setae: anterior inclinate, posterior 2 lateroclinate, ocellars almost as long as anterior orb, strongly divergent, pvt only little shorter than these and crossed; all setae dark brown.

[FIGURE 14 OMITTED]

Thorax: Yellow, but scutum more orange-yellow and with a pair of lateral longitudinal stripes running from just medial to pprn to the lateral edge of scut as far as base of subapical setae, disc of scut remaining clear yellow; mtn yellow centrally, dark brown laterally. Chaetotaxy: 2 pprn and short setula between them, 2 ntpl, 1 posthu, 1 sa, 1 pa, 1 post ia, 3+3 dc, those in front of scutal suture very short, but easily discernable from scutal setulae, scutal setulae in in 6-8 irregular rows between dc lines, with 1 strong prscut pair, scut with subapicals about 1.5x length of scut and basals about 0.7 length of subapicals, 1 anepisternal with short seta above it and several setulae anterior to these, 1 katepisternal with short seta in front, which in turn has a few short setulae in front of it.

Wing: Hyaline with a uniformly diffuse faint smokey grey infuscation, veins brown, vein closing anal cell convex with minute stump vein at middle; distance between [R.sub.2+3] and [R.sub.4+5] about 0.8 that between [R.sub.4+5] and [M.sub.1+2]; distance between crossveins about equal to length of apical section of vein Cu, costa with break near hu crossvein; costal setulae along anterior margin brown with several black spine-like setulae interspersed and about 9 similar setulae on dorsal aspect of costa; [R.sub.4+5] and [M.sub.1+2] parallel up to apex of wing. Haltere yellow, concolourous with pleura.

Legs: Yellow, femora hardly dilated, fore femur with long setulae on dorsal and posterior aspects, setulae on legs becoming darker towards apical segments, setulae on dorsum of tarsomeres 4 and 5 longer than diameter of tarsomere, tarsomere 5 brown on apical half or more.

Abdomen: All tg brown dorsally and yellow laterally, st all pale yellow and poorly sclerotized, st 5 with long lateral setae and along posterior margin with small lobes bearing setulae, st 6 reduced to a narrow V-shaped sclerite (similar to that in O. elongata sp.n., Fig. 19b), tg especially towards apex of abdomen with marginal and lateral setae almost as long as tg.

[FIGURE 15 OMITTED]

Postabdomen: tg 6 a little shorter than dorsal length of ep, which unlike tg is completely yellow, ep broader and longer in its upper part (similar to that in gracilipes; contrasting with that infusciceps), cerc large and distinctly setose, prg large with anteriorly directed setae and notched posterior edge, surs with apical section long and narrow,psg simple, distiph complex without the punctate lateral sclerotized plate seen in similar species.

Length: [male] body 2.0 mm, wing 1.9 mm; [female] body 2.5 mm, wing 2.6 mm.

Female.

As in male, but palp spatulate and larger; brown scutal markings can be much more developed, either stripes reaching anterior margin of pprn and darker, or whole of scutum darkened leaving only short pale yellow middle area in front of scut; katepisternum and meron dark; stronger setae dark brown to black; darkening of tarsomere 5 variable from half to apical 1/4 of segment. Postabdomen: tg 7 divided; cerc relatively large, long and narrow compared to congeners; tg 5 with strong marginal setae more or less concentrated on pigmented area laterally; hypr thinly sclerotized, but distinct and microtrichose.

Holotype: [male] TANZANIA, W Usambara, Lushoto [04[degrees]47'S:38[degrees]17'E], 18.viii.2003, S. Kleynberg (TAUI).

Paratypes: TANZANIA: 1 [female] Usambara Mts, Gologolo, 1900 m, 23.viii.1996, A. Freidberg; 1 [female] Njombe, 10 km SE Rt 84, 2000 m, 27-28.viii.1996, A. Freidberg; 1 [female] nr Ngozi Crater, Rt A345, 1900 m, 1.xi.1996, A. Freidberg (all TAUI).

Oroschyromya dubia (Lamb, 1914), comb. n. Figs 16, 17

Chiromyia dubia: Lamb 1914: 353.

Lamb wrote that he had 11 specimens, four of which were males. I examined these specimens and found them to be all females belonging to two species. The holotype has the abdomen missing, but otherwise has all the characters agreeing with the remaining series. One other of the five specimens at the Natural History Museum in London is a dissected female and it agrees with the figure given in this article (Fig. 17). Another specimen (BMNH) and three more (CUMZ) belong to a species of Gymnochiromyia. They have a thorax with chaetotaxy typical of that genus: the mtn is a clear yellow; the tg are uniformly dark chocolate brown and completely shiny, only the membrane separating one tg from the other is pale yellow; the prscut acrs are particularly strong. I am unable to assign this species with confidence to any of the recently described species from southern Africa (Ebejer 2008b), so until more material, including males, becomes available, it remains unnamed. I labelled each of the four specimens as 'Gymnochiromyia female, sp. indet.'.

Diagnosis: An orange-yellow species with large hypopygium having vertically elongate ep. In spite of weak pra and pa setae suggesting this might be a Notiochyromya, the long surs, conical prg and accesssory ventral hyp plate properly place this within Oroschyromya. The female postabdomen also shows strong affinities with this genus. So far, it is the only species in the genus known from a relatively lowland habitat.

Redescription:

Male.

Head: All yellow except for black oc triangle; fr narrow, at widest point less than half width of head; strongly narrowed anteriorly: at level of antennae 0.4 width that at level of anterior oc and 0.3 width of one eye viewed in front. Gena: only a little narrower in front than behind; in profile, below middle of eye, about 0.6 height of eye; pale yellow and pale-haired; ocp in profile narrowly visible behind eye; with short postocular setulae in one irregular row, the top 4 developed into short dark setae; isolated lower postgenal seta long. Mouthparts small, all yellow; setulae of buccal margin moderately developed. Face poorly sclerotized and small, hardly visible. Antenna yellow, second segment with short dark seta dorsally; third segment round, finely pubescent: hairs short, only those on lower margin as long as diameter of arista at base; arista dark almost throughout and completely bare. Chaetotaxy: 3 orb, all markedly reclinate, the anterior also slightly inclinate, middle and posterior orb closer together than middle is to first; pvt short and crossed; 1 vti and 1 vte strong; ocellars almost as long as hind orb, proclinate and divergent; about 8 short setulae across middle of fr and about 6 on each orb plate. All setae dark brown, setulae yellow.

Thorax: In profile, anterior margin of scutum rectangular; scutum, scut, mtn and all pleura yellow and without defined pattern, paler on pleura. Chaetotaxy: 1 pprn and another about half its size, 1 posthu, 2 ntpl, 1 pra and 1 sa (both short), 1 pa, 1 post ia, 1 dc with another half its size or less, in front of it, scutal setulae in 6-8 irregular rows at level of transverse suture between dc lines, 4 slightly stronger prscut setulae in a transverse row between dc, and 2 more on each side between dc and pa; subapical and basal scut as usual, 1 anepisternal and 1 katepisternal, all setae dark brown, only on pleura yellow.

[FIGURE 16 OMITTED]

[FIGURE 17 OMITTED]

Wing: Hyaline, veins pale brown; distance between [R.sub.2+3] and [R.sub.4+5] about 0.8 that between [R.sub.4+5] and [M.sub.1+2]; distance between crossveins from 0.8 length of apical section of vein Cu or about equal to it. Haltere pale yellow.

Legs: Not modified except for slightly thicker femora; fine setulae scattered on all pairs of legs, in addition to longer setae on fore femur; mid tibial apicoventral seta absent; claws and pulvilli normal.

Abdomen: Entirely yellow; pale setae, about half to two thirds length of tg. Postabdomen: ep yellow and distinctly elongated from top to bottom, cerc also elongated and densely setulose; surs long and narrow; hyp basally with large distal section that fuses with ep and small accessory plate; ph apd long and narrow; ej apd moderately developed, narrow in profile; prg large, sclerotized and conical with strong setae on anterior surface; psg small and narrow.

Female.

Scutum with 4 pale brown stripes: 2 along midline reaching about half way to scut, and one on each side of these between dc and ia lines reaching just beyond wing base; setae and setulae darker and stronger; otherwise as male. Postabdomen: elongate lateral sclerites of tg 7 of distinctive shape due to irregular margins, these sclerites partly overlapping st 8; setae on st 8 short; hypr sclerotized, cerc small oval.

Length: [male] body 1.5 mm, wing 1.5 mm; [female] body 1.6 mm, wing 1.6 mm.

Type material examined: SEYCHELLES: [female] (holotype) 'Mahe 08-9, Seychelles Exp. / Prof. J.S. Gardiner' (BMNH); 69 (paratypes) same data (3 BMNH, 3 CUMZ).

Other material examined: MAURITIUS: 3 [male] 1 [female] Wolmar, 1-2 km S, 21.v.2000, J.W. Ismay, coast roadside (OXUM); 1 [male] 1 [female] same data (NMWC).

Distribution: Mauritius, Seychelles.

Oroschyromya elgonae sp. n. Fig. 18

Etymology: From the type locality, Mt Elgon in Uganda.

Diagnosis: Yellow species with pair of longitudinal brown stripes on scutum commencing from behind transverse suture and running posteriorly along lateral margin of scut; 1+4 dc setae, but main identification features are in postabdomen.

Description:

Male.

Head: Yellow; fr narrow, at anterior oc only 1.2x width of eye, narrowing only slightly towards antennae where width is 0.8 that at anterior oc; oc triangle brown; ocp yellow, in profile, convex. Eye: elongated oval, 1.7 times as long as high. Gena: slightly recessed and broad, below middle of eye about 1.2x height of eye; pale setulose with 2 long setae on oral margin just below vibrissal angle. ocp, in profile clearly visible behind eye, with short postocular setulae in two irregular rows with additional setulae on disc; isolated lower postgenal seta pale but distinct. Mouthparts small, all pale yellow, palp particularly short oval. Face depressed, barely visible. Antenna with all segments yellow, second with pale long seta dorsally; third segment somewhat elongated ventrally, finely pubescent: pubescence a little shorter than diameter of arista at base; arista black except at extreme base of second segment and whole of first 2 segments where it is yellow. Chaetotaxy: 3 orb, anterior inclinate, middle and posterior orb reclinate, all equidistant from each other; 1 vti and 1 vte a little longer than hindmost orb;pvt crossed, about half length of vt; ocellars a little more than half length of vt; all setae pale; 1 setula in each of the spaces between the orb and about 8 pale setulae scattered on fr.

Thorax: Predominantly yellow; scutum with a small rectangular black patch anteriorly at neck and 2 brown stripes commencing behind transverse suture and extending along lateral margin of scut; remainder of scut and pleura all yellow; mtn brown. Chaetotaxy: 2 pprn, one short, 1 posthu, 2 ntpl, absent pra, 1 sa, 1 pa, 1 short post ia, 1+4 dc, scutal setulae in 4 irregular rows between dc lines; absent longer prescut acrs; scut with usual subapical and basal marginals, but no other setae or setulae; 1 anepisternal at middle of hind margin with a shorter seta above it, 1 katepisternal close to upper hind corner; both sclerites with additional pale setulae in front of setae. All setae on thorax yellow.

[FIGURE 18 OMITTED]

Wing: Hyaline with pale yellow tinge over entire membrane; veins pale brown, a little lighter at base; vein closing anal cell convex with a minute stump vein at its middle; distance between [R.sub.2+3] and [R.sub.4+5] about 0.7 that between [R.sub.4+5] and [M.sub.1+2]; distance between crossveins about twice length of posterior crossvein; length of apical section of vein Cu about 2.8x length of posterior crossvein and about 0.9x distance between crossveins. Haltere pale yellow.

Legs: Yellow, all segments unusually slender for the family and rather long; tarsomere 5 of all legs dark brown in apical third; fine setulae scattered on all pairs of legs, in addition longer setae present on fore femur; mid tibial apicoventral seta absent; claws black except at extreme base and pulvilli normal.

Abdomen: Rather elongate and narrow; dorsally, tg 1 yellow, tg 2 dark brown, tg 3-5 paler brown; only on lateral margins pale; st yellowish white; setulae not numerous, short, about a quarter length of tg, but along hind margin of each tg is a row of uniform brown setae about 2/3 length of tg; tg 6 clearly visible, about half length of tg 5 and 0.8 length of ep; st 5, on each posterolateral corner with a more sclerotized circular part bearing stronger setulae.

Postabdomen: ep yellow, large, higher than long; cerc narrow, elongate and distinctly setose; surs strongly curved, shorter than prg, prg with complex folds at base and 1 long anteroventrally directed seta, long and narrow apically, psg very long and narrow, hyp very broad in profile, ph apd long and narrow, ej apd small, distiph complex with lateral punctate plate towards apex.

Female. Unknown.

Length: [male] body 2.5 mm, wing 2.3 mm.

Holotype: [male] UGANDA: Mt Elgon, Sasa [01[degrees]15'N:34[degrees]32'E], montane forest, alt. 3300 m, fogging of Afrocrania volckensi (Cornaceae), 10-19.ix.1997, T. Wagner (in alcohol, ZSMC).
Key to subfamilies of Chyromyidae

1   Occiput convex to flat, never distinctly concave; 3
    well-developed orb, anterior usually inclinate; scutum without ihu
    seta; wing veins [R.sub.4+5] and [M.sub.1+2] parallel or slightly
    convergent towards apex; mid tibia usually without any apicoventral
    seta, if seta present (some species of Somatiosoma and
    Notiochyromya) then not longer than diameter of tibia at apex; scut
    often with additional setulae and/or setae; male postabdomen with
    more or less hemispherical ep completely external to tg 6
                                                            Chyromyinae

--  Occiput concave; 0-6 orb of variable length, never inclinate;
    when more than 2, these are usually short and progressively shorter
    anteriorly; scutum with inclinate ihu seta or setula (except in
    Krifomyia and Tethysimyia); wing veins [R.sub.4+5] and [M.sub.1+2]
    parallel (Paraphanisoma and Krifomyia), convergent (Tethysimyia) or
    divergent (Aphaniosoma) towards apex; mid tibia always with long
    apicoventral seta; scut never with more than 2 pairs of marginal
    setae; male postabdomen never with hemispherical ep, this lies
    partially or entirely within tg 6         Aphaniosominae subfam. n.

Key to genera of Chyromyinae

1   Distinct pra seta behind transverse suture in depression between
    ntpl and scutum; prsut dc absent; acrs never differentiated from
    numerous mesonotal setulae except 2-4 prscut; head, in profile,
    with longest part towards lower eye margin; gena narrow, less than
    half height of eye at middle; mid tibia often with short
    apicoventral seta (shorter than diameter of tibia at
    apex)                                         Notiochyromya gen. n.

--  Distinct pra seta absent; if setulae present in this area, these
    are similar to setulae elsewhere on scutum; if setula in this
    position is interpreted as a short pra seta (some Chyromya and
    Gymnochiromyia) then mid tibial apicoventral seta completely
    absent; prsut dc seta may be present and acrs often differentiated;
    head, in profile, longer towards upper eye margin and gena usually
    broader than half height of eye at middle                         2

2   Well-developed post ia seta present; scut bare on disc and with
    only 2 pairs of marginals; fr significantly narrower towards
    antennae (i.e. strongly convergent anteriorly); male cerci
    distinctly modified or spinose                 Oroschyromya gen. n.

--  Posterior ia absent; if seta or setula present, it is shorter
    than prscut acrs; scut with or without additional marginals or
    discals; fr usually less markedly convergent; cerci simple        3

3   Occiput distinctly convex, with numerous setae and setulae on
    disc in addition to those around ocp foramen and on postocular
    margin; fr parallel-sided or almost so; discal cell usually extends
    beyond middle of wing; males with dilated femora (not
    Afrotropical)                            Chyromya Robineau-Desvoidy

--  Occiput flat or slightly concave, no ocp setulae on disc,
    although rarely 2 or 3 short setulae may be present outside
    postocular row on each side; fr with sides converging towards
    antennae; discal cell extends only to middle of wing; males with
    little or no femoral dilation                                     4

4   Scutellum with setulae on disc and sometimes with additional
    marginal seta apart from usual 2 pairs; prscut dc never present;
    prscut setae or setulae poorly developed; short mid tibial
    apicoventral seta often present                    Somatiosoma Frey

--  Scutellum with only 2 pairs and bare on disc; prscut acrs longer
    than any setulae that may be situated in post ia area; prscut dc
    sometimes present; never with apicoventral seta on mid tibia
                                                  Gymnochiromyia Hendel

Key to genera of Aphaniosominae

1   Scutal setulae in 2 acrs rows, sometimes irregular; incurved ihu
    seta/setula almost always present; sa and post ia setae absent;
    [R.sub.4+5] and [M.sub.1+2] always divergent towards wing apex
                                                     Aphaniosoma Becker

--  Scutal setulae in 4-10 rows, not differentiated into acrs;
    incurved ihu seta/setula sometimes present; at least post ia
    present, even if short; [R.sub.4+5] and [M.sub.1+2] parallel or
    convergent towards wing apex                                      2

2   Pre-alar seta present in depression behind transverse scutal
    suture; incurved ihu setula present; sa distinct; [R.sub.4+5] and
    [M.sub.1+2] parallel; head longer than high; eye margins on fr
    strongly convergent towards antennae; fr never inflated and not
    projecting above and in front of eye margin; 1-3 well-developed
    reclinate orb; pvt often absent, but if present, usually only one
    minute setula or entirely missing in some specimens of the same
    species; carina very indistinct, at most just visible immediately
    below lunule only; gena narrow, less than half height of eye
                                                 Paraphaniosoma gen. n.

--  Pre-alar and sa setae absent, if sa present, not easily
    differentiated from adajacent setulae; ihu setula absent;
    [R.sub.4+5] and [M.sub.1+2] parallel or convergent towards wing
    apex; head higher than long; fr parallel-sided or nearly so,
    projecting anteriorly above antennae, appearing somewhat inflated;
    0-4 short and usually inconspicuous orb; pvt present or absent, if
    present, always very short; carina distinct; gena broad, often much
    broader than half height of eye                                  3

3   Facial carina exceptionally well-developed, broadening below
    antennae; antennae lie in deep fossae; gena very broad, almost
    equal to height of eye or more; katepisternal seta absent; scutal
    setulae in 4-6 irregular rows between dc lines, short and sparse;
    other scutal setulae scanty, short to minute; wing veins
    [R.sub.4+5] and [M.sub.1+2] parallel up to apex of wing; hu
    crossvein thickened                               Krifomyia gen. n.

--  Facial carina narrow, less conspicuous, less widened below
    antennae; antennae, though appearing recessed, do not lie in deep
    fossae; gena about as broad as half height of eye or a little more;
    katepisternal seta present; acrs in 4-10 rows, more numerous and
    longer, other scutal setulae more numerous and longer; wing veins
    [R.sub.4+5] and [M.sub.1+2] convergent towards apex of wing; hu
    crossvein normal                                Tethysimyia gen. n.


Males

1   Scutellum with 4 marginal setae only; abdomen (Fig. 9b) with dark
    brown midline spots on tergites and ep, also with brown lateral
    areas on each tg, postabdomen Fig. 12            tripunctata sp. n.

--  Scutellum with 6-8 marginal setae (if with short setae on disc,
    see key to females); abdominal markings various                   2

2   Scutellum with 8 marginal setae; scutum shiny with barely a trace
    of pruinosity; abdomen lacking dark spots, postabdomen Figs 5, 6
                                                          lucida sp. n.

--  Scutellum with 6 marginal setae; scutum uniformly pruinose yellow
    to pale brown                                                     3

3   Sternite 2 with a large shiny spot medially, leaving only a
    narrow margin of st with dense brown pruinosity, postabdomen
    Fig. 7                                             monticola sp. n.

--  Sternite 2 with a small medial shiny spot occupying middle 1/3 of
    diameter of st, leaving wide margin of brown pruinosity on st,
    postabdomen Fig. 4                                  filigera sp. n.

Females

1   Scutellum with 4 marginal setae and no setulae on disc
                                                     tripunctata sp. n.

--  Scutellum with 6-8 marginal setae; with or without setulae on
    disc                                                              2

2   Scutellum with 6 marginal setae (the pair between basals and
    subapicals are set medially; with or without a few short setae on
    disc); mtn pale                                                   3

--  Scutellum with 8 marginal setae; with or without a few additional
    short setae on disc; if with 6 setae on scut, then with short setae
    on disc and mtn dark                                              6

3   Scutellum without short setae on disc                             4

--  Scutellum with short setae on disc; tergites with dark spots on
    lateral borders only, and these only on tg 3-6       sp. A, Namibia

4   Abdomen (Fig. 9a) with a small brown or black rounded spot on tg
    3 to 6 laterally, and often with a darkening along midline that may
    or may not form a discrete spot; each spot is slightly shining and
    surrounded by a clear yellow margin; head short, in profile
    strongly sloping and frons narrower than 1/3 width of head at
    vertex, postabdomen Fig. 11                       sexspinosa (Lamb)

--  Abdomen with large, oval, lateral, black spots completely shining
    and almost reaching anterior and posterior margin of each tg      5

5   Abdomen with shiny brown transverse bands on tergites
                                                        filigera sp. n.

--  Abdomen with large black lateral spots on tergites, postabdomen
    Fig. 8 monticola sp. n.                                           5

6   Scutellum with 8 marginal setae, but no setae on disc; mtn
    yellow; abdomen with short longitudinal dark line at apex formed by
    midline spot on tg 6 and 7; bright pale yellow species with yellow
    vestiture                                            sp. B, Namibia

--  Scutellum with 8 marginal setae (occasionally 6) and with short
    setae on disc; mtn dark; abdomen with spots on tg 5 and 6 out of
    line relative to those on tg 2-4, thus closer to midline of
    respective tg                                        sp. C, Namibia


Males

1   1 prsut + 3-5 postsutural dc setae                                2

--  0 prsut + 1-2 postsutural dc setae

2   Cerci at least 3x longer than wide and ca 1/3 height of ep,
    viewed in profile; prg long and narrow, as long as or longer than
    cerci, postabdomen Figs 19a, b
                                                        elongata sp. n.

--  Cerci shorter, at most 1/4 height of ep; prg shorter and
    spine-like, clearly broader basally                               3

3   Metanotum dark brown; 1+4-5 dc, scutal setulae arranged in 8
    irregular rows and numerous from anterior to posterior; post ia
    seta strong; tarsomere 5 of all legs brown, postabdomen Fig. 14
                                                         bicolor sp. n.

--  Metanotum pale brown; 1+3 dc, scutal setulae arranged in 4-6
    rows, sparse from anterior to posterior; post ia short; tarsomere
    5 of all legs yellow, postabdomen Fig. 18            elgonae sp. n.

4   Scutum entirely pale yellow; wing hyaline                         5

--  Scutum with distinct longitudinal stripes; wing uniformly
    infuscated pale yellowish brown                                   7

5   Head ca 1.5x as broad as long; post ia seta weak; surstylus
    narrow, only slightly curved from base to apex, postabdomen
    Fig. 16                                                dubia (Lamb)

--  Head ca 2x as broad as long; post ia seta strong; surstylus in
    basal half broad and curved more-or-less at right angles, Figs
    12d, 23b                                                          6

6   Surstylus not twisted along its long axis; psg very large with
    several lobes, angled at 90[degrees] medially, postabdomen Fig. 23
                                                     peruncinata sp. n.

--  Surstylus twisted along its long axis; psg much smaller, straight
    and blade-shaped, [male] postabdomen Fig. 12         affinis sp. n.

7   Antenna entirely yellow; head with frontal setulae black; scutum
    with 4 brown stripes, legs with all tarsomeres yellow, postabdomen
    Fig. 22                                           gracilipes sp. n.

--  Third antennal segment brown; head with frontal setulae pale
    yellowish white, scutum with 6 longitudinal stripes; legs with
    distal three segments of all tarsomeres dark, [male] postabdomen
    Fig. 21                                            fusciceps sp. n.

Females

[NB: females of O. elgonae, O. gracilipes and O. fusciceps remain
unknown and are not included in this key.]

1   Tergite 6 divided dorsally, forming two large, disc-shaped
    divisions laterally; tg 4-6 with very strong setae                2

--  tg 6 normal; setae on apical segments of abdomen not unusually
    developed                                                         3

2   Segment 6 with 5 or 6 strong setae on each disc-shaped sclerite;
    segment 4 with very strong setae along entire posterior margin;
    segment 5 with strong setae medially, and following a short
    interruption, laterally on posterior margin, postabdomen Fig. 13
                                                         affinis sp. n.

--  Segment 6 with 2-4 strong setae on each disc-shaped sclerite;
    segments 4 and 5 with strong setae along edge of posterior margin,
    close-set dorsally and more widely-spaced along lateral edge of
    posterior margin                                 peruncinata sp. n.

3   0+1-2 dc; scutal stripes absent and metanotum entirely yellow,
    postabdomen Fig. 17                                    dubia (Lamb)

--  1+3-5 dc; scutum and metanotum not as above                       4

4   Scutum with dark brown longitudinal stripes that may be confluent
    anteriorly; stripes extend to lateral aspect of scutellum leaving
    only middle 1/3 yellow; metanotum brown; abdominal tg dark brown,
    postabdomen Fig. 15                                  bicolor sp. n.

--  Scutum yellow, if with stripes, then these narrow and
    predominantly on posterior half, not extending onto scutellum;
    metanotum yellow (occasionally brown); abdominal tg yellow or
    brown, if the latter, then often with brown marking divided
    centrally leaving a pale yellow line on apical tg 1-3, postabdomen
    Fig. 20                                             elongata sp. n.
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