Submitted to: Emerald Ash Borer Research and Technology Development Meeting
Publication Type: Other
Publication Acceptance Date: 1/30/2015
Publication Date: 7/1/2016
Citation: Duan, J.J., Schmude, J.M. 2016. Biology, life history, and laboratory rearing of Atanycolus cappaerti (Hymenoptera:Braconidae), a larval parasitoid of the invasive Emerald Ash Borer (Coleoptera: Buprestidae). Emerald Ash Borer Research and Technology Development Meeting. Page 60.
Technical Abstract: Atanycolus cappaerti Marsh and Strazanac is a native North American parasitoid that has been found to parasitize the invasive emerald ash borer (EAB), Agrilus planipennis Fairmaire, which has killed millions of ash trees since it was first detected in Michigan. A native parasitoid like A. cappaerti may be the preferred biocontrol agent as it has already developed a new association with the invasive pest and well adapted to North American habitats. In addition, this native parasitoid has a relatively longer (4-5 mm) ovipositor than the introduced larval parasitoids Tetrastichus planipennisi and Spathius agrili. More importantly, native parasitoids will minimize disruption of an ecosystem as they have already co-evolved with the ecosystem and have less adverse impacts on nontarget hosts. In this study, we investigated the biology, life cycle, rearing, and diapause behavior of A. cappaerti in the lab with normal rearing conditions (23-27C, with 55-75 % RH and 16:8 (L:D) hr photoperiod). Our study shows that A. cappaerti can complete its life cycle in less than one month (26.5 days) but may frequently require more under our normal lab rearing conditions. The parasitoid larvae emerges from the egg and quickly molts through 6 instars in approximately six days and begins to spin a cocoon for pupation for which it may enter a diapause. Adult female wasps had a median survival time of 10.5 weeks which was found to be significantly different than males with a survival time of nine weeks. The female oviposition peaked at three weeks old and had a mean of 11.38 (1.9 S.D.) progeny. The ratio of diapaused:emerging progeny started at 50:50 from week one and increased in percentage diapaused with each week until all progeny entered facultative diapauses starting at week 11. The native range of A. cappaerti is widely distributed throughout the Midwest and northeast United States which receives temperatures around 25C for many months (June-September) during the EAB growing season. The diapause patterns shown by A. cappaerti in this study show that it is likely for many populations to only have a single generation a year, which along with it being a solitary parasitoid may attribute it to being a less successful parasitoid for augmentative biocontrol.