Attraction of Paratelenomus saccharalis (Hymenoptera: Platygastridae), an Egg Parasitoid of Megacopta cribraria (Hemiptera: Plataspidae), to Host-Associated Olfactory Cues

Paratelenomus saccharalis (Dodd) (Hymenoptera: Platygastridae) is an egg parasitoid of Megacopta cribraria (F.) (Hemiptera: Plataspidae). Although the parasitoid has been previously reported in parts of Africa, Europe, Asia, and Australia, it was first reported in North America in 2013 on M. cribraria that was introduced from Asia into North America in 2009. Field observations showed that P. saccharalis females readily parasitize eggs of M. cribraria. However, the cues used by the parasitoid for host location have not been investigated. It was hypothesized that P. saccharalis uses olfactory cues to locate M. cribraria. The objective of this study was to test the attraction of P. saccharalis to host-associated cues in Y-tube olfactometer bioassays. Compared to the control of no host plant or eggs, female P. saccharalis showed significantly greater attraction to M. cribraria-damaged soybean, M. cribraria eggs only, and damaged soybean plus M. cribraria eggs, in separate bioassays. However, the parasitoid did not show significant attraction to undamaged soybean. The results suggest that host location by P. saccharalis is mediated by olfactory cues from the soybean host and M. cribraria eggs. This is the first behavioral study to demonstrate the response of P. saccharalis to induced soybean volatiles.