Development of a behavior parameter in classically conditioned parasitic wasps that detect changes in odor intensity

Trained parasitic wasps, used to sense volatile compounds in a device called the Wasp Hound, have been used to detect the presence or absence of a target chemical. This study attempted to determine if the behavioral response of trained parasitic wasps could be used to detect a change in the concentration of volatile chemical compounds produced from ground coffee. Three behaviors were examined as functions of four levels of coffee placed in a 200 mL jar. Results indicated that behavior was correlated with the level of coffee tested when examining the rotation of a wasp around the odor source as it searched for the source. The rate of change of parameter γ (dγ/dt), the cycles the wasp travelled around the odor source, increased as the dosage of coffee was increased. Unexpectedly, this also revealed a bias in the direction of rotation for the wasps based on the average behavioral response. Wasps moved counter- clockwise around the odor source as they moved toward the odor source. This revealed a method of foraging around an odor source that may indicate how wasps and other insects use their antennae and movement behavior to find odor sources of food, hosts, and mates when in close proximity.