Circadian regulation of oviposition rhythm in Drosophila agumbensis and Drosophila nagarholensis (Diptera)

Abstract

The oviposition rhythm of two species of montium, namely Drosophila agumbensis and Drosophila nagarholensis was analysed under constant conditions such as constant light (LL), constant dark (DD) and 12 light/12 dark (LD). The members of the montium are the largest, wide spread and heterogeneous, and the intricacies of their wide spread nature may lie in their adaptability to diverse environment. An endogenous circadian pacemaker controls the timing of many events such as oviposition, hatching and eclosion occurring at a particular time of the day, which enhances the survival of an organism. This study is an attempt to understand the timing of oviposition at different light conditions. Over 80% of the egg laying occurred during scotophase for both the species. The peak of oviposition was observed at six hours after the lights were turned off. Shorter period was observed in LL and LD, and it was ∼24 h in DD condition. The number of eggs laid in LD was more compared to LL and DD.

Keywords:

• montium
• Circadian rhythm
• Oviposition
• D. agumbensis
• D. nagarholensis

Acknowledgements

We are grateful to the UGC New Delhi for the financial assistance, UGC SAP-DSA III UGC NRCBS-MKU and Chairman, Department of Studies in Zoology, University of Mysore for the facility.