2010 Annual Report
1a.Objectives (from AD-416)
(1) Conduct explorations for natural enemies of the emerald ash borer (includes foreign exploration in the Far East as well as a search for native natural enemies of indigenous buprestid beetles), choose suitable investigation areas, inventory natural enemies attacking target pest, investigate the structure of the enemy complex, and conduct field studies of their impact on the target pest. (2) Perform bioecological studies on promising natural enemies discovered includes studies on life history and behavior, host specificity (Asiatic species), synchronization with the pest, physiological tolerance to different climatic factors, and establishment of priorities in utilization of promising species based upon their biological characteristics. (3) Quarantine services for beneficial insects includes quarantine handling of natural enemies of high priority plant pests for other in-house projects (Asian longhorned beetle, soybean aphid, lygus bugs, brown marmorated stingbug) and pass-thru services for state and federal agencies.
1b.Approach (from AD-416)
Investigate natural enemies of emerald ash borer in Far East: inventory biotic agents, assess role in population dynamics of pest, set priorities for importation, and ship promising species to Newark for further study. Candidate species that appear to be monophagous or oligophagous, or which have many suspect host records will be subjected to laboratory tests in quarantine on North American species selected for study. Both choice and no-choice tests will be used in evaluating host range. Study natural enemies of indigenous buprestid beetles to identify effective candidate species that could be used effectively against EAB in North America. Experiments will be conducted to find optimum temperatures, relative humidity, and photoperiod needed to rear the most promising species. Releases will be made in areas having moderate to high host populations. Monitoring of EAB population density and natural enemy buildup and dispersal after colonization will be used to interpret the efficacy of biological control agents established. Screen incoming shipments of natural enemies of other pests for other ARS CRIS units as well as other institutions involved with biological control research, to remove undesirable organisms and obtain pure cultures of natural enemies other invasive species. Ship approved natural enemies to cooperators.
Two species of Emerald Ash Borer parasitoids (Tetrastichus planipennisi and Sclerodermus sp.) were collected in Heilongjiang and Hebei Provinces, China and subsequently imported to the BIIR quarantine laboratory in 2008 additional strains or species of Tetrastichus sp were collected from the Primorski Kraj region of Russia and subsequently imported to the BIIR quarantine laboratory in 2009. In-house field studies resulted in the discovery of five species of parasitic Hymenoptera, including Balcha indica, Eupelmus pini and Dolichomitus vitticrus, Spathius laflammei and Atanycolus nigropyga, which attack various instars of EAB larvae.
Approximately 3000 individuals of T. planipennisi were released at each of the seven study sites against EAB in MI and MD from 2009 to 2010. In addition, two other previously introduced parasitoids (Spathius agrili and Oobius agrili reared by USDA APHIS and FS) were also released (at the study sites) in MI, where their potential impact on EAB populations was evaluated by placing EAB eggs in bark slits on ash tree trunks, using sentinel logs or sticks infested with EAB eggs and caging egg-laying adult EAB. Results from 2010 spring and summer sampling indicated that all three introduced parasitoids were able to parasitize their emerald ash borer hosts and successfully overwinter (i.e., reach adulthood the following spring) in both Michigan and Maryland. The larval endoparasitoid T. planipennisi and egg parasitoid O. agrili were consistently recovered from all four study sites, whereas the larval ectoparasitoid Spathius agrili was recovered less frequently (only in one study site in Michigan). While parasitism by O. agrili was relatively low (<5% of the emerald ash borer eggs), the parasitism rate of emerald ash borer larvae by T. planipennisi was higher (10-30%) one year after the most recent field release. Additionally, field studies in Michigan revealed that immature stages of emerald ash borer were attacked by a complex of native North American parasitoids including Atanycolus spp, Spathius spp, and Balcha indica. Collectively, these native parasitoids caused a 10-40% parasitism rate across different study sites.
QUARANTINE SERVICES: From 2006 to 2010, about 13 permitted consignments were received annually by the Quarantine Facility, consisting of over 4935 specimens and 13 different beneficial species. A total of 259 identification requests were submitted to the ARS Systematic Entomology Laboratory for determination.
Successful introduction of a biological control of emerald ash borer. The emerald ash borer, first discovered in Michigan in 2002, is a serious invasive pest that has killed millions of ash trees in North America. One egg parasitoid (Oobius agrili Zhang and Huang) and two larval parasitoids (Tetrastichus planipennisi Yang and Spathius agrili Yang) introduced from northern China have been released to combat the emerald ash borer in the US. Following multiple field releases (by ARS Scientists from Newark DE) of these parasitoids into native North American ash stands, both wild populations and experimentally established cohorts of emerald ash borers were sampled at different seasons of the year (spring, fall, and winter). Results showed that all three exotic parasitoids were capable of parasitizing their hosts and overwintering (i.e., reaching adulthood the following spring) in the US (Maryland and Michigan). This marks the first successful evaluation of establishment of the introduced parasitoid (T. Planipennisi) in North America, and demonstrates the potential for controlling the invasive emerald ash borer pest with classical biocontrol technology.
Duan, J.J., Fuester, R.W., Wildonger, J.A., Taylor, P.B., Barth, S.E., Sven-Eric, S. 2009. Parasitoids attacking the emerald ash borer (Coleoptera: Buprestidae) in western Pennsylvania. Florida Entomologist. 92(4):588-592.
Ulyshen, M.D., Duan, J.J., Bauer, L.S. 2010. Interactions between Spathius agrili (Hymenoptera: braconidae) and Tetrastichus planipennisi (Hymenoptera: Eulophidae), larval parasitoids of Agrilus planipennis (Coleoptera: Buprestidae). Biological Control.
Joe, P.N., Ter Braak, C.J., Dixon, P.M., Duan, J.J., Hails, R.S., Huesken, A., Lavielle, M., Marvier, M., Scardi, M., Schmidt, K., Tothmeresz, B., Schaarschmidt, F., Van De Voet, H. 2009. Statistical aspects of environmental risk assessment of GM plants for effects on non-target organisms. Environmental Biosafety Research. 8:65-78.
Lundgren, J.G., Gassmann, A., Bernal, J., Duan, J.J., Ruberson, J. 2009. Ecological Compatibility of GM Crops and Biological Control. Crop Protection. 28(12):1017-1030.
Duan, J.J., Lundgren, J.G., Naranjo, S.E., Marvier, M. 2010. Extrapolating non-target risk of Bt crops from laboratory to field. Biology Letters. 6:74-77.