2009 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.
A foreign exploration trip was taken to three northern Provinces of China (Jilin, Heilongjiang, and Hebei) in September, 2008, for the purpose of collecting natural enemies of the emerald ash borer (EAB). Two species of EAB parasitoids (TETRASTICHUS PLANIPENNISI and SCIERODERMUS SP.) were collected in Heilongjiang and Hebei Provinces, and subsequently imported to the BIIR quarantine laboratory in October, 2008. Through collaboration with USDA APHIS, an additional strain or species of TETRASTICHUS SP was collected from the Primorski Kraj region of Russia, and subsequently imported to BIIR quarantine laboratory in May, 2009. In-house field studies conducted in 2008 resulted in discovery of three species of parasitic Hymenoptera, including BALCHA INDICA, EUPELMUS PINI, and DOLICHOMITUS VITTICRUS, from late instar EAB larvae and prepupae in western Pennsylvania. Continued field survey in Pennsylvania in 2009 led to discovery of two additional species of parasitic Hymenoptera, SPATHIUS LAFLAMMEI and ATANYCOLUS NIGROPYGA, which attack late instars of EAB larvae. These extant or indigenous parasitoids may play a potential role in suppressing populations of EAB in North America. In addition, this study was noteworthy because two species (S. LAFLAMMEIR, A. NIGROPYGA) had not been found in the Great Lakes Region in previous studies.
All the EAB larval parasitoids (indigenous or foreign) mentioned above have been successfully reared and maintained in the quarantine laboratory using field collected EAB larvae inserted into ash sticks or laboratory reared EAB larvae on ash logs. Approximately 2,000 individuals of T. PLANIPENNISI were reared in quarantine, and released against EAB in MI and MD in the summer of 2009. In addition, two other previously introduced parasitoids (SPATHIUS AGRILI and OOBIUS AGRILLI reared by USDA APHIS and FS) were also released in MI, where their potential impact on EAB populations was being evaluated by placing EAB eggs in bark slits on ash tree trunks, using sentile logs or sticks infested with EAB eggs, and caging egg-laying adult EAB. As of August of 2009, two species of the introduced parasitoids (T. PLANIPENNISI and O. AGRILI) were successfully recovered from larval and/or egg cohorts of EAB established in two of the three study sites in MI.
A total of 7 permitted consignments were received by the Quarantine Facility, consisting of 734 specimens, 3 different species (2 potential beneficial species). From these consignments and cultures established from previous consignments, a total of 13 outgoing shipments (4653 specimens, 8 species) were shipped to six cooperators in four states plus Canada. A total of 116 identification requests were submitted to the ARS Systematic Entomology Laboratory for determination.
Successful release and establishment of a larval parasitoid imported from China. The emerald ash borer is a serious invasive pest that has killed millions of ash trees in North America since its first discovery in MI in 2002. The success of classical biological control of this invasive pest depends upon the successful release and establishment of control agents from the place where the pest originated. Two species of EAB parasitoids (T. PLANIPENNISI and SCLERODERMUS SP) were imported from regions in China, where EAB most likely originated, and underwent quarantine screening in October of 2008. The most promising candidate, T. planipennisi, was successfully reared and released in collaboration with USDA Forest Service and Maryland Department of Agriculture at selected study sites in MI and MD in 2009, and recently recovered from EAB larvae collected at two of the three sites in MI. This marks the first successful recovery of this parasitoid in North America, and demonstrates the potential for controlling the invasive pest such as EAB with classical biocontrol technology.
Desjardins, C. A., Gundersen-Rindal, D.E., Hostetler, J.B., Tallon, L.J., Fadrosh, D.W., Fuester, R.W., Pedroni, M.J., Haas, B.J., Schatz, M.C., Jones, K.M., Crabtree, J., Forberger, H., Nene, V. 2008. Comparative genomics of mutualistic viruses of Glyptapanteles parasitic wasps. Genome Biology. 9:R193.