Electrophysiological responses of gustatory sensilla on the ovipositor of the parasitoid Diachasmimorpha longicaudata (Hymenoptera: Braconidae).

FM DEVESCOVI; VAN LOON; SEGURA

Congreso; III Congress of the Latin American Association of Chemical Ecology (ALAEQ),; 2014

Diachasmimorpha longicaudata is an endoparasitoid of thephritid fruit flies. In Argentina it is being reared on Ceratitis capitata and it usually incurs in superparasitism.The aim of this study was to evaluate if host discrimination ability (behavioraly tested in other experiments) could be linked to the electrophysiological response of neurons enervating chemosensory sensilla from the ovipositor towards chemical cues from hosts of different parasitization status.Scanning electron microscopy (SEM) was performed to corroborate the presence of these gustatory sensilla.Spike frequency and adaptation of single gustatory sensillum to haemolymph of parasitized [0h (PL 0h) or 24h (PL 24h) after parasitization] or unparasitized (UPL) 3rd instar Ceratitis capitata larvae was studied. We were able to record a clear electrophysiological activity from single neurons enervating gustatory receptors located on the ventral valves of the ovipositor of Diachasmimorpha longicaudata. Regarding host discrimination ability, the frequencies of action potentials produced by haemolymph of parasitized or unparasitized Ceratitis capitata larvae were not different. Given the fact these parasitoids attack concealed hosts and quality assessment should probably occur at ovipositor insertion, other stimuli should be tested in order to reveal the mechanisms of such behavior.