Electrophysiological Responses of Gustatory Receptor Neurons on the Labella of the Common Malaria Mosquito, Anopheles quadrimaculatus (Diptera: Culicidae).

We recorded electrical responses from sensory cells associated with gustatory sensilla on the labella of female Anopheles quadrimaculatus Say to salt, sucrose, quinine (a feeding deterrent), and the insect repellent, N,N-diethyl-3-methylbenzamide (DEET). A salt-sensitive cell responded to increasing concentrations of sodium chloride. A second cell was activated by increasing sucrose concentrations, while quinine, DEET, or a mixture of quinine + DEET elicited spike activity from a third cell, an apparent bitter- or deterrent-sensitive cell. Both quinine and DEET suppressed activity of the sugar-sensitive cell; sucrose suppressed activity of the bitter- or deterrent-sensitive cell. These results demonstrate separate gustatory pathways for a feeding stimulant and aversive contact cues mediated through distinct sensory inputs on the labellum. This sensory appendage may serve as a useful target to disrupt feeding behavior in this and other anopheline species, which transmit diseases like malaria to human populations.

Duke Scholars

Author Jackson T Sparks Medical Education