Regulation of sensitivity in the peripheral chemoreceptor systems for host-seeking behaviour by a haemolymph-borne factor in Aedes aegypti

Abstract

The taking of a blood meal and subsequent development of eggs by a female mosquito is reported to suppress host-seeking behaviour. This change in behaviour may be partly mediated by changes in certain chemosensitive antennal afferent neurones that influence the behaviour of female mosquitoes. Electrophysiological activity of the lactic acid-excited neurons to lactic acid—a normal host-attractant substance—is depressed following a blood meal. This reduction in lactic acid sensitivity is coincident with the reported inhibition of host-seeking behaviour. The reduction in lactic acid sensitivity is reversible; this sensitivity returns to the pre-blood-fed level following oviposition. Like the inhibition of host-seeking behaviour, the reduced lactic acid sensitivity is due to a transfusable, haemolymph-borne factor. A role for the peripheral sensory system in the control of behaviour in female mosquitoes is discussed.