Attraction and oviposition response of gravid female black flies (Simulium vittatum) to S. vittatum eggs

The oviposition response of gravid Simulium vittatum IS-7 (Diptera: Simuliidae) to putative oviposition pheromones in or on the eggs of S. vittatum IS-7 was investigated in the laboratory.  A series of single choice, binary choice, and petri dish assays was conducted to observe the behavioral responses of gravid S. vittatum IS-7 females when presented freshly oviposited conspecific eggs, extracts of conspecific eggs, and isolated chemicals.  Recent research in the Simulium damnosum Complex in a binary choice chamber has demonstrated that freshly oviposited eggs and their volatiles are attractive to gravid S. damnosum females.  The response of gravid S. vittatum IS-7 females demonstrated that fresh conspecific eggs are an oviposition stimulant but not a long range volatile attractant.  The oviposition stimulation and lack of long range attraction of conspecific eggs on gravid S. vittatum IS-7 females demonstrates the presence of a contact or short range oviposition stimulant associated either with in or on the eggs.