Location: Beneficial Insects Introduction Research
2012 Annual Report
1: Explore for natural enemies (parasitoids) of EAB in its native range and evaluate their suitability for introduction. 1a - Explore for parasitoids of EAB in its native range. 1b - Evaluate the suitability of discovered parasitoid for introduction to North America for EAB control. 2: Evaluate impacts of extant (indigenous) and previously introduced parasitoids on populations of EAB, particularly in northeastern and/or Midwestern states. 3: Develop effective mass rearing technologies for hymenopteran parasitoids of EAB and other invasive pests. 3a - Determine the key life history parameters of the concerned parasitoid species. 3b - Determine the optimal host stage and host density (or host to parasitoid exposure ratio). 3c - Determine the optimal environmental conditions for adult parasitoid survival, oviposition, and progeny development.
Previous study sites in Michigan and Maryland have been continuously surveyed for evaluation of the three introduced parasitoids (S. agrili, T. planipennisi, and Oobius agrili). In addition, four new sites in Maryland have been established and large numbers of those parasitoids were released there. Our surveys showed that several hymenopteran parasitoids including the three introduced agents have become associated with EAB in Michigan. Among these parasitoids, T. planipennisi was the most abundant, accounting for >50% of all parasitoid individuals collected; low levels (1 – 5%) of parasitism of EAB larvae by this biocontrol agent were consistently detected at survey sites in both Michigan and Maryland. Separately, the native parasitoid, Atanycolus spp., was the second abundant group, resulting in 19% average parasitism rate of EAB larvae. Other native parasitoids were also found at various survey sites in Michigan or Maryland, but much less abundant than T. planipennisi and Atanycolus spp.
Following the development of the host plant-based method to rear emerald ash borer larvae, we continued studying the life history and biology of the biocontrol agent (T. planipennisi) and determined the critical fitness values of its progeny. We discovered that offspring production and critical fitness parameters (body size and sex ratio) of T. planipennisi from parasitized EAB larvae are influenced by host plant substrate, host-parasitoid group size, and/or host to parasitoid ratio in the primary exposure assay. These findings have led to significant improvement to the current method for rearing T. planipennisi.
QUARANTINE SERVICES: A total of 63 permitted consignments were received by the Quarantine Facility, consisting of 7995 pest specimens, and 7114 parasitoids in 3 different genera. A total of 9 outgoing shipments, 3311 pest specimens, and 1432 parasitoids in 2 genera. A total of 4 identification requests were submitted to the ARS Systematic Entomology Laboratory for determination.
Duan, J.J., Oppel, C.B., Ulyshen, M., Bauer, L., Lelito, J. 2011. Biology and life history of Tetrastichus planipennisi (Hymenoptera: Eulophidae), a larval endoparasitoid of the emerald ash borer (Coleoptera: Buprestidae). Florida Entomologist. 94(4):933-940. Taylor, P.B., Duan, J.J., Fuester, R., Hoodle, M.S., Driesche, R. 2012. Parasitoid guilds of Agrilus woodborers (Coleoptera: Buprestidae): their diversity and potential for use in biological control. Psyche. Article ID 813929. Duan, J.J., Taylor, P.B., Fuester, R.W. 2011. Biology and life history of Balcha indica, an ectoparasitoid attacking the emerald ash borer, Agrilus planipennis, in North America. Journal of Insect Science. 11:127. Available:insectscience.org/11.127. Staub, J.E., Delannay, I.Y. 2011. USDA, ARS Cucumis hystrix-derived U.S. processing cucumber inbred backcross line population. HortScience. 46:1428-1430. Duan, J.J., Oppel, C.B. 2012. Critical rearing parameters of Tetrastichus planipennisi (Hymenoptera: Eulophidae) as affected by host-plant substrate and host-parasitoid group structure. Journal of Economic Entomology. 105:792-801. Duan, J.J., Bauer, L.S., Hansen, J.A., Abell, K.J., Van Driesche, R. 2012. An improved method for monitoring parasitism and establishment of Oobius agrili (Hymenoptera: Encyrtidae) an egg parasitoid introduced for biological control of the emerald ash borer (Coleoptera: Buprestidae) in North America. Biological Control. 60(3):255-261. DOI: 10.1016/j.biocontrol.2011.11.007. Duan, J.J., Yurshenko, G., Fuester, R. 2012. Occurrence of emerald ash borer (Coleoptera: Buprestidae) and biotic factors affecting its immature stages in far eastern Russia. Environmental Entomology. 41:245-254.