Influence of mating duration on fecundity and fertility in two aphidophagous ladybirds

Abstract:  The influence of different mating durations on fecundity and fertility has been studied in two aphidophagous ladybirds, Cheilomenes sexmaculata and Coelophora saucia . Pre-oviposition period decreased while fecundity and fertility increased with increase in mating duration in both the ladybird species. The increase in fecundity with longer mating durations is probably due to the female response because of cryptic female choice. Mating of 10-s duration resulted in oviposition but of unviable eggs probably because of lack of sperm transfer. A minimum duration of 1 min of mating was probably essential for fertilization of the eggs. Absence of spermatophore in the reproductive tract of females is indicative of direct sperm transfer in both the ladybird species. Trend of fertility (similar fertility at 1 and 5 min followed by increase at 60 min which was again similar to that at complete mating) indicates probable sperm transfer in spurts in C. sexmaculata while continuous transfer in C. saucia is indicated by continuous increase in fertility with increase in mating duration.