Visual and olfactory cues for mate recognition in male pumpkin beetle, Aulacophora foveicollis

Abstract

Visual and olfactory mediated cues play a major role in mate selection in different groups of insects. This study aimed to observe if there is any role of mate color (under different wavelengths) and/or cuticular hydrocarbons in mate selection of Aulacophora foveicollis. In this study, visual cues and olfactory cues showed a vital role for male A. foveicollis to find mates. Males preferred (81%) orange (similar body colour) coloured glass model than white (52%) and black (49%) under the visible spectrum; whereas under the UV spectrum white coloured model was more preferred (77%) than orange (60%) and black (48%) coloured. In contrast, unresponsive males were very high though white coloured model was still preferred (36.67%) than orange (24.44%) or black (22.22%) coloured under IR spectrum. It was also observed that body surface waxes can play alone an olfactory cue for male mate selection (attraction was 67%) from short distance. Under the visual spectrum, when both visual and olfactory cues were presented, attraction of males toward all orange (93%), white (74%), and black (71%) coloured glass bead model increased. Even under UV and IR spectra attraction increased when body surface extract of female was applied on the glass models though the preference was more towards white coloured model than orange as previous. Male A. foveicollis showed less preference towards black colour. These works provide evidence that both visuals and olfactory cues can act separately as well as synergistically to find mates for male insects. These findings will be helpful for sustainable pest management program.