Electrophysiology and Behaviour in Banana Pseudostem Weevil Odoiporus longicollis Olivier to Conspecific Chemical Cues

Abstract

An understanding of the role of semiochemicals in insect biology can be used for developing IPM tools. The olfactory and behavioural responses of banana pseudostem weevils (BPW) Odoiporus longicollis Olivier to semiochemicals isolated from conspecific insects were investigated by electroantennography (EAG) and Y-tube olfactometer bioassays. Volatiles were collected from male and female weevils, separately and together from both sexes by air entrainment. Dichloromethane extracts of male and female weevils were used as stimuli in electrophysiological study. The observations revealed that the antennae of both male and female produced significant EAG responses (1.378±0.350 mV and 1.704±0.246, respectively) to male volatile compared to other stimuli tested. In two-choice experiments, more males (p=0.001, χ2=11.84) and females (p= 0.033, χ2=4.57) were attracted to male volatiles. Significant responses of both sexes to headspace volatiles from male extracts during EAG and olfactometer experiments revealed that specific volatile compounds emitted by male played a significant role in aggregation. These results might enable identification of male specific pheromone components, which can enhance effectiveness of pheromone trapping for O. longicollis.