Circadian rhythms of adult emergence and activity but not eclosion in males of the parasitic wasp Nasonia vitripennis.
An endogenous circadian system is responsible for the rhythms observed in many physiological and behavioural traits in most organisms. In insects, the circadian system controls the periodicity of eclosion, egg-laying, locomotor and mating activity. The parasitoid wasp Nasonia vitripennis has been extensively used to study the role of the circadian system in photoperiodism. In this study, behavioural activities expected to be under the control of the endogenous circadian system were characterized in Nasonia. Male emergence from the host puparium is rhythmic under light-darkness conditions while eclosion from the own pupal integument is not rhythmic but continuous. Following entrainment in light-dark conditions, males show robust free-running circadian activity rhythms with a period (tau, tau) of approximately 25.6h in constant darkness. While the endogenous circadian system is enough to trigger male emergence in Nasonia, light seems to have a modulatory effect: when present it induces more males to emerge. Our results add to the understanding of chronobiological phenotypes in insects and provide a basis towards the molecular characterization of the endogenous circadian system in Nasonia.
Chronobiology, Center for Behavior and Neurosciences, University of Groningen, P.O. Box 14, 9750 AA Haren, The Netherlands. r.c.bertossa@rug.nl
Rinaldo C
RC
Bertossa
Jeroen
J
van Dijk
Domien G
DG
Beersma
Leo W
LW
Beukeboom
D000818:Animals; D002940:Circadian Rhythm / Q000528:radiation effects; D004175:Diptera / Q000254:growth & development / Q000469:parasitology*; D005260:Female; D006790:Host-Parasite Interactions; D008027:Light; D008297:Male; D013045:Species Specificity; D014863:Wasps / Q000254:growth & development* / Q000502:physiology* / Q000528:radiation effects