Document Detail

The same photoperiodic clock may control induction and maintenance of diapause in the spider mite Tetranchus urticae.
MedLine Citation:
PMID:  8032087     Owner:  NLM     Status:  MEDLINE    
In the spider mite Tetranychus urticae, both diapause induction (which takes place during the larval and nymphal stages) and diapause maintenance (in the adult female) are under photoperiodic control. The question of whether or not the same photoperiodic clock is involved in both photoperiodic reactions was investigated in eight strains of the spider mite, originating from different localities in Europe. The methods employed consisted of (1) determination of the relative importance of the photophase and scotophase in the two photoperiodic reactions; (2) comparison of photoperiodic response curves for diapause induction and diapause maintenance; and (3) determination of the effect of light breaks on the capacity of long nights to maintain diapause, and comparison with the effect of light breaks in diapause induction experiments. The scotophase appeared to be much more important than the photophase for both diapause induction and diapause maintenance. In all strains the critical daylength for diapause maintenance, measured at the moment of saturation of the response to long daylengths, was identical to the critical daylength for diapause induction. However, the critical daylength for diapause maintenance appeared to be labile; it shifted gradually to shorter values as the mites were kept in the cold for a longer period of time, or were kept at a higher temperature for a progressively longer period of time after their stay in the cold room. This seems to reflect a gradual loss of photoperiodic control of diapause maintenance as diapause development proceeds. Photoperiods close to the critical daylength appeared to be less strong with regard to diapause maintenance than shorter daylengths. Quantitative differences in the "strength" of different daylengths were found in all strains investigated. Interruption of the night by short pulses of light revealed either one or two peaks of sensitivity in the night, or one broad "trough" where the two peaks had merged. However, in each case maximal sensitivity to the light breaks occurred at the same position in the night for diapause induction and diapause maintenance. The many similarities found lead to the conclusion that most probably the same photoperiodic clock mechanism is involved in both diapause induction and diapause maintenance in T. urticae.
D S Koveos; A Kroon; A Veerman
Related Documents :
18685187 - Specific detection of buckwheat residues in processed foods by polymerase chain reaction.
16950947 - Diagnosis and management of food-induced anaphylaxis: a national survey of pediatricians.
77367 - Oral cromoglycate in treatment of adverse reactions to foods.
12720397 - The elusiveness of coffee aroma: new insights from a non-empirical approach.
18183527 - Biomarkers of environmental and workplace boron exposure.
23074397 - Clinical utility of vitamin d testing: an evidence-based analysis.
Publication Detail:
Type:  Journal Article    
Journal Detail:
Title:  Journal of biological rhythms     Volume:  8     ISSN:  0748-7304     ISO Abbreviation:  J. Biol. Rhythms     Publication Date:  1993  
Date Detail:
Created Date:  1994-08-15     Completed Date:  1994-08-15     Revised Date:  2008-11-21    
Medline Journal Info:
Nlm Unique ID:  8700115     Medline TA:  J Biol Rhythms     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  265-82     Citation Subset:  IM    
Department of Pure and Applied Ecology, University of Amsterdam, The Netherlands.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Circadian Rhythm*
Cold Temperature
Mites / growth & development*
Time Factors

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

Previous Document:  Doppler ultrasound findings in Osler-Weber-Rendu disease with hepatic involvement: a case report.
Next Document:  Diurnal and seasonal rhythms of neuronal activity in the suprachiasmatic nucleus of humans.