Reproductive biology of Ooencyrtus nezarae, an egg parasitoid of the kudzu bug Megacopta cribraria in Japan

The kudzu bug, Megacopta cribraria has recently been invaded into US and causing serious damages on soybean in the South. Since Ooencyrtus nezarae (Hymenoptera: Encyrtidae) and  Paratelenomus saccharalis (Hymenoptera:Platygastridae) parasitize M. cribraria eggs in Japan, we examined parasitization behavior of O. nezarae to determine its effectiveness as a biological control agent of M. cribraria in Japan. O. nezarae is polypahogus and parasitizes eggs of more than 5 hemipteran species. Although 0-day-old to 7-day-old M. cribraria eggs were suitable for parasitism by O. nezarae, O. nezarae parasitized fewer numer eggs per egg mass in 4-day-old or older egg masses than younger ones. O. nezarae could hyperparasitize final instar larvae of the conspecific or P. saccharalis in parasitized hosts. On attacking a host egg mass consisting unparasitized and recently parasitized eggs, females preferred to oviposit in .the parasitized eggs to unparasitized ones. On the parasitized host, a female did not make a hole, but used the hole made by the previous ovipositing female for oviposition. Due to the facts that it is polyphaous and capable of hyperparasitizing P. saccharalis, Ooencyrtus nezarae dominantly parasitizes M. cribraria eggs on kudzu in late season in Southern Japan.