The oviposition and host-seeking behavioral responses of Simulium vittatum (Diptera: Simuliidae) to putative oviposition pheromones in or on conspecific eggs and potential host-seeking attractants were investigated in the laboratory. A series of behavioral bioassays was conducted to observe the oviposition responses of gravid S. vittatum females when presented freshly oviposited conspecific eggs, extracts of conspecific eggs, identified chemical compounds from extracts of conspecific eggs, and potential host-seeking attractants. The response of gravid S. vittatum females demonstrated that factors on freshly oviposited conspecific eggs were an oviposition stimulant but not a long range volatile attractant. Host-seeking responses of black flies to 1-octen-3-ol, carbon dioxide, and other compounds in a Y-tube olfactometer indicated the potential of using specific blends of host-seeking attractants to bait a black fly trap and provide a more effective method to monitor transmission of Onchocerca volvulus.