Diel periodicity and circadian control of oviposition by Cryptophlebia illepida (Lepidoptera: Tortricidae)

Oviposition rhythms were determined for Cryptophlebia illepida Butler under different photoperiods. When the photoperiod was 12:12 or 15:9 (L:D) h at 22.5 degrees C, approximately 88.4 and 87.9% of oviposition occurred during the photophase. However, when the photoperiod was 10:14 (L:D) h, only 51.8% of the eggs were laid during the photophase. Oviposition occurred primarily within 2 h before the onset of the scotophase in all tests with cyclic photoperiods. In addition, C. illepida adjusted their oviposition timing to accommodate a shortened photoperiod. When the photoperiod of 15:9 (L:D) h was shortened during testing by starting the scotophase 3 h earlier, C. illepida resynchronized oviposition within 3 d so that 88.5% of their eggs were laid during the photophase. Oviposition of C. illepida was shown to be under circadian control with a 23.0-h free-running period in complete darkness