The Effect of Conspecifics on Oviposition Site Selection and Oviposition Behaviour in Aedes Togoi (Theobold) (Diptera: Culicidae)

Two opposing hypotheses are tested regarding the choice of oviposition sites by female Aedes togoi (Theobold) mosquitoes: ( i ) conspecific avoidance—females discriminate against sites harboring conspecifics to reduce intraspecific competition for their offspring and ( ii ) conspecific attraction—females prefer sites with conspecifics because their presence indicates suitable conditions for larvae. Under laboratory conditions, A . togoi females laid many more eggs on rearing water (LRW) containing conspecific larvae, their waste, bacteria, and food supplements than on rearing water alone (RM). In another experiment, females showed an oviposition preference for LRW sites that were devoid of A . togoi eggs compared with those harboring 50 (0.3 eggs/mL) conspecific eggs. Further, it was discovered that females laid their eggs at several sites rather than at a single suitable site. Possible reasons for such choices are discussed.