Identification and field verification of aggregation-sex pheromone from the predaceous bug, Arma chinensis

Arma chinensis is a predaceous insect species that can effectively suppress a wide range of agricultural and forest insect pests in the orders Lepidoptera, Coleoptera, Hymenoptera and Hemiptera in Northeast Asia. Adult A. chinensis males produce an aggregation-sex pheromone from dorsal abdominal glands and artificial aggregation-sex pheromone can attract adults of both sexes. The aggregation-sex pheromone consists of (E)-2-hexenal, (E)-2-hexen-1-ol, benzaldehyde and benzyl alcohol. Both antennae and proboscises of A. chinensis females and males responded to components from male dorsal abdominal gland extracts. (E)-2-hexenal and benzaldehyde elicited significantly higher EAG responses than those with (E)-2-hexen-1-ol and benzyl alcohol. Benzyl alcohol elicited the weakest EAG responses, although benzyl alcohol was the most abundant of the four major components in male dorsal abdominal gland extracts. A field bioassay using trap catches demonstrated that (E)-2-hexenal and benzyl alcohol were key components of the pheromone for catching conspecific adults. Single pheromone components were the least attractive to A. chinensis in the field.