QUANTITATIVE ASSESSMENT OF INSECT OLFACTOMETER PERFORMANCE BY EXPERIMENTAL FLOW-ANALYSIS

Biocontrol organisms respond to olfactory cues with behavior which can affect their efficacy as pest control agents, Investigations into olf actory stimuli and responses often use four-armed olfactometers for la boratory experiments. Performance evaluations of the olfactometers hav e generally been qualitative and based on visual assessment. A quantit ative technique for characterizing the air flow and gas mixing in a fo ur-armed olfactometer was developed. Ethylene gas was injected into th e flow stream for each channel of the olfactometer. Samples of air at various locations in the olfactometer chamber were drawn through hypod ermic probes and the concentration of ethylene in the samples were det ermined by gas chromatography, Flow boundaries between adjacent channe ls were not distinct and mixing between channels was observed, althoug h concentration spatial gradients were high in the boundary regions. M ixing increased as flow neared a central outlet. Gross assessments of organism behavior in olfactometers appear valid in spite of flow mixin g. (C) 1996 Academic Press, Inc.