Intraspecific variability of olfactory responses in Cerambyx welensii Küster (Coleoptera, Cerambycidae). Influence of anatomical, physiological and experimental factors

Abstract

Intraspecific variability of EAG responses in Cerambyx welensii has been studied.We have not found significant differences of EAG responses neither between sexes nor types of solvent, paraffin oil and hexane, but there was a highly significant variability of responses between individuals (0,92 mV +/- 0,6. Mean +/- DT) to (E)-2-hexenal (50% v/v). More than 68% of individual variability can be explained by the combination of the previous aptitude of insects, its physiological state (vitality at the moment of study) and the capillary's diameter in the reference electrode. Anatomical features of the individuals had not influence in the response. In order to avoid or minimize the effect caused for this variability, it is advisable to carry out EAG tests with insects obtained under controlled conditions. In other case, the EAG responses must be standardized using a standard stimulus, as well as to homogenize the tip diameter of the reference electrode.