Electroantennographic responses of red flour beetle Tribolium castaneum Herbst (Coleoptera: Tenebrionidae) to volatile organic compounds

The red flour beetle Tribolium castaneum Herbst (Coleoptera: Tenebrionidae) is the most encountered and destructive stored product insect pest of cereal grains and seeds. Although this beetle has been used as a model organism for many decades, there is no systematic knowledge about antennal detection of host and non-host volatiles. Electroantennogram responses to 94 selected volatile organic compounds including alkanes, alkenes, alcohols, aldehydes, ketones, carboxylic acids, esters, terpenoids and aromatic compounds were recorded from both sexes of T.castaneum. Overall, female and male T.castaneum exhibited similar electroantennography (EAG) responses. Compounds eliciting the strongest EAG responses within compound groups of chemical similarity were undecane, 1-hexen-3-ol, octanal, 2-heptanone, hexanoic acid and ethyl hexanoate. Comparison of vapour pressure and EAG amplitudes within homologous series of compounds revealed responses to undecane, octadecane, octanal, nonanal, 2-heptanone, hexanoic acid and octanoic acid as outstanding. Given that systematic EAG screenings have not been conducted before, these are the best candidates for evaluation in future behavioural studies to unravel their potential for application in integrated pest management strategies of T.castaneum.