Characterization of the electroantennographic response by Cerambyx welensii Küster and Prinobius germari Germar (Coleoptera: Cerambycidae) to olfactory stimuly

Abstract

Xylophagous cerambycids of Cerambyx and Prinobius genus can play an important role in «oak decline» in Spain. New trends in the integrated pest management are dealing with control strategies based on the relation between olfactory perception of semiochemicals and insect behaviour. Electroantennography of olfactory stimuli enables to interpret the significance of the olfactory stimulation in host selection, an unknown aspect within many xylophagous insects. Cerambyx welensii and Prinobius germari (Coleoptera, Cerambycidae), have responded in EAG tests to two different compounds: a green-leaves volatile (E)-2-hexenal and turpentine; C. welensii also responded to acetic acid. Strong stimulatory conditions (20 μl of stimulating blend at 1:1 v/v doses) favour high EAG responses, without causing antennal saturation. Under these stimulatory conditions, and using complete insects, we have obtained stable EAG responses during, at least, five hours. Results show a good aptitude of these species for deeper electrophysiological experiments (such chromatography linked to electroantennography), in search of the olfactory cues involved in host location.