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ARS Home » Southeast Area » Tifton, Georgia » Crop Protection and Management Research » Research » Publications at this Location » Publication #305840
Title: Computational modeling and experimental validation of odor detection behaviours of classically conditioned parasitic wasp, Microplitis croceipes.

Author
item ZHOU, ZHONGKUN - Lincoln University - New Zealand
item KULASIRI, DON - Lincoln University - New Zealand
item RAINS, GLEN - University Of Georgia
item SAMARASINGHE, SANDHYA - Lincoln University - New Zealand
item Olson, Dawn

Submitted to: Biotechnology Progress
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/1/2014
Publication Date: 12/20/2014
Citation: Zhou, Z., Kulasiri, D., Rains, G.C., Samarasinghe, S., Olson, D.M. 2014. Computational modeling and experimental validation of odor detection behaviours of classically conditioned parasitic wasp, Microplitis croceipes. Biotechnology Progress. doi: 10.1002/btpr.2025.

Interpretive Summary: A prototype chemical sensor named the ‘Wasp Hound’ that utilizes five contained and classically ¬conditioned parasitoid wasps to detect volatile odors was successfully implemented in a previous study. To further improve the sensitivity of odor¬ and odor concentration detection of the Wasp Hound, searching behaviors of a food-conditioned wasp in a confined area with the conditioning odor were recorded. Unfed wasps were food-conditioned to 20 mg of coffee when associated with food and subsequently tested to 5, 10, 20 and 40 mg of coffee. A stochastic model was developed and validated based on three recorded positive behavioral responses (walking, rotation around the odor source and self¬-rotation) from conditioned wasps at four different test dosages. The model was capable of reproducing the behaviors of conditioned wasps, and can be used to improve the ability of the Wasp Hound to assess changes in odor concentration. The model simulation results show that the behaviors of conditioned wasps are significantly different when tested at different coffee dosages than those they had been trained to. We infer that the searching behaviors of conditioned wasps are based on the temporal and spatial neuron activity of olfactory receptor neurons and glomeruli which are strongly correlated to the training dosage. The overall results demonstrate the utility of mathematical models for interpreting experimental observations, and gaining novel insights into the dynamic behavior of a classically ¬food-conditioned parasitic wasp species, as well as broadening the practical uses of the Wasp Hound.

Technical Abstract: To further improve the sensitivity of odor¬ and odor concentration detection of the Wasp Hound, searching behaviors of a food-conditioned wasp in a confined area with the conditioning odor were recorded. The experiments were recorded using a video camera. First, the wasps are individually hand conditioned to coffee odor at 20 mg dosage; they are tested to 5, 10, 20 and 40 mg coffee dosage. In order to study the wasp’s behavior at each test dosage, quantitative data were extracted from the experimental video files using the video tracking software Tracker® and stored in a Microsoft Excel database for analysis. By observing the conditioned wasp behaviors to the different coffee treatments in the recorded video, three variables R, ', and a were formulated to represent three major behaviors. FR describes the distance that wasps travel towards or away from the centre hole (where coffee odor is emitted); ' describes the rotation that the wasp travels around the centre hole, clockwise or counter¬clockwise; and a describes self¬-rotation (wasps rotate around themselves) either clockwise or counter¬clockwise. The model simulation results show that the behaviors of conditioned wasps are significantly different when tested at different coffee dosages than those they had been trained to. The model was capable of reproducing the behaviors of conditioned wasps, and can be used to improve the ability of the Wasp Hound to assess changes in odor concentration.