Oviposition response of black flies (Simulium vittatum) to potential oviposition stimulants in the laboratory

Oviposition response of the black fly, Simulium vittatum, to potential attractants and stimulants were investigated in the laboratory with different olfactometers.  The response of gravid S. vittatum in a binary choice chamber demonstrated that fresh conspecific eggs stimulated oviposition substrate preference.  A petri dish bioassay demonstrated that gravid S. vittatum were stimulated to oviposit quicker when an aqueous or hexane extract of conspecific eggs was applied to the oviposition substrate in comparison to a control.  Analytical chemistry, gas chromatography coupled with mass spectrometry, was used to identify potential oviposition stimulation factors in the active extracts.  This series of bioassays has helped the understanding of black fly oviposition behavior by demonstrating an oviposition stimulant factor present on S. vittatum eggs.