NO INHIBITORY EFFECT ON RECEPTOR NEURON ACTIVITY BY SULFUR ANALOGS OFTHE SEX-PHEROMONE COMPONENT (Z)-5-DECENYL ACETATE IN THE TURNIP MOTH,AGROTIS-SEGETUM (LEPIDOPTERA, NOCTUIDAE)

Olfactory responses from the entire antenna and from single antennal s ensilla of the male turnip moth, Agrotis segetum (Lepidoptea: Noctuida e Schiff.), were recorded after stimulation of the antenna with the se x pheromone component, (Z)-5-decenyl acetate (Z5-10:OAc), and three su lphur analogues of this compound. Adaptation of olfactory receptor neu rones tuned to Z5-10:OAc was investigated after pre-exposure of these receptor neurones to the key stimulus and to the three sulphur analogu es. Both electro-antennographic and single sensillum recordings reveal ed that the sulphur analogues had a significantly decreased effect com pared to the natural stimulus. The pre-exposure experiments demonstrat ed that no further inhibition of neural activity was observed than cou ld be expected from receptor neurone adaptation. Earlier reports, desc ribing sulphur analogues as possible hyperagonists acting on moth pher omone receptor neurones, are not supported by the present study.