Electrophysiological and Behavioral Evidence for (E)-2-Hexenal as a Female-Attracting Pheromone Produced by Disturbed Megacopta cribraria (Hemiptera: Plataspidae)

Megacopta cribraria (F.) (Hemiptera: Plataspidae), commonly known as the kudzu bug, is an invasive insect that was first recorded in the United States in Georgia in 2009. Since its introduction it has spread across the Southeast, infesting soybean crops and significantly reducing crop yield. Chemical pesticides pose environmental concerns and are not compatible with biological control. This investigation was conducted to identify M. cribraria pheromones that could be utilized in an insect trap for environmentally friendly monitoring and integrated pest management. Open Y-track olfactometer assays revealed that M. cribraria females are attracted to volatiles produced by disturbed M. cribraria. Gas chromatography mass spectrometry analysis of volatile organic compounds produced by disturbed and undisturbed M. cribraria revealed the presence of tridecane and (E)-2-decenal in secretions from both disturbed and undisturbed M. cribraria, whereas (E)-2-hexenal was detected only in secretions from disturbed M. cribraria. The behavioral responses of M. cribraria to (E)-2hexenal and tridecane were measured with open Y-track olfactometer assays. Females were significantly attracted to (E)-2-hexenal while males were not. Neither sex was attracted to tridecane. Electroantennographic assays demonstrated an electrophysiological response of female M. cribraria antennae to (E)-2-hexenal but not to tridecane or (E)-2-decenal. Male antennae were unresponsive to the chemicals tested. These data support the conclusion that (E)-2-hexenal is a female-attracting pheromone produced by disturbed M. cribraria and suggest that (E)-2-hexenal could be used to lure female M. cribraria into pheromone-baited traps.