2012 Annual Report
1a.Objectives (from AD-416):
Objective 1: Explore for natural enemies of insect pests (e.g., olive fruit fly, Lygus bugs), and wood borers (e.g., longhorned beetles and emerald ash borers) and other pests as identified as high priority targets by the ARS Office of National Programs.
• Sub-objective 1A - Discovery and collection of potential biological control agents for service to other laboratories that provide further development of the natural enemies.
• Sub-objective 1B - Quantitative measurements and observations that lead to new documentation on biology of potential biological control agents and their hosts.
• Sub-objective 1C - Genetic studies that enhance the chance of success with new biological control agents.
Objective 2: Identify, colonize and evaluate the most promising natural enemies and ship them to U.S. cooperators. Results of laboratory (including genetics and behavior) and field studies will be used to improve the ability to predict key factors for application to future programs.
• Sub-objective 2A – Identification, colonization, and evaluation of efficacy of biological control agents.
• Sub-objective 2B – Documentation of life table parameters and biological characteristics.
• Sub-objective 2C – Genetic parameters as predictors of successful biological control.
1b.Approach (from AD-416):
Biological control through the introduction of natural enemies continues to be one of the most effective, cheap, and environmentally safe solutions to problems created by introduced pests and invasive species. We propose to take advantage of the experienced staff, biologically strategic location, and excellent facilities of the European Biological Control Laboratory in Montpellier, France, and its satellite laboratory in Thessaloniki, Greece, to discover potential biological control agents, characterize them genetically, evaluate their efficacy, and describe relevant aspects of their bionomics. Scientific output from these efforts will include taxonomic, genetic, and biological descriptions of important species in the Palearctic and Ethiopian regions. The target species of these efforts will include the olive fruit fly, vine mealybug, the European grapevine moth, the diamondback moth, the olive psyllid, Lygus bugs, and Asian longhorned beetle. In addition, we will use model species (the southern green stink bug and the tarnished plant bug) to test the hypothesis that the success of parasitoid wasps as biological control agents can be predicted by examining genetic parameters.
For objective 1 (explore for and characterize natural enemies of priority pests) we shipped lygus parasitoids from France to US cooperators; Moroccan lygus parasitoids were mass reared for field release in DE and CA by ARS-Newark and NJDA. We discovered a parasitoid that attacks the kudzu bug and sent collections to ARS-Stoneville for host range studies. We made plans for foreign exploration for natural enemies of bagrada bug and collaborative research on kudzu bug with ARS-Stoneville. Exploration in NE and SW China was conducted and an egg of citrus longhorned beetle was found in Southern China and being identified. We continued improving methods of rearing olive fly parasitoids and studied their nutritional ecology. SCA 0212-22000-022-06T with the French INRA supported basic research on olive fly parasitoids. Two agents have been released in California and Israel. Further evidence of establishment of one species in CA was obtained this summer. We examined mating barriers between Chinese and French populations of olive fruit fly to define the taxonomic status of Chinese flies. Research in France and Italy on citrus and Asian long horned beetles with Italian agency MINOPRIO (0212-22000-024-8T) developed a release technique for an egg parasitoid of CLB in Northern Italy. For Objective 2 (identify, evaluate and colonize promising candidates for US cooperators) we continued studies comparing the impact of French and Israeli strains of a vine mealybug parasitoid on a California mealybug strain. A preliminary study of the behavioral response of codling moth and European grape vine moth to different odors was conducted in the laboratory with a visiting New Zealand research fellow. We collected field samples and developed microsatellite markers of an introduced lygus parasitoid for a retrospective genetic analysis of U.S. lygus biocontrol programs. Research on invasive long horned beetles analyzed within-gallery temperature data from an entire year in trees infested with CLB to validate a degree-day model for beetle development. Studies of hibernation by diapausing CLB egg parasitoids in actual outdoor conditions were begun to improve diapause survival rate. American Farm School MOU 0212-22000-023-11M provides our Greek substation with lab and office space, facilitating exploration and field work in the Balkan region. Ancillary project (0212-22000-024-11T) involves DoD, university and Greek agencies in faunistic survey and population monitoring in northern Greece for sand flies and mosquitoes, including monitoring West Nile virus and malaria. We tested traps and other management approaches. MOU 0212-22000-023-12M with Benaki Phytopathology Institute supports mutual-interest research on local strains of olive fly pathogens. MOU 0212-22000-022-07M with Joint Genomic Center (Sophia University, Bulgaria) facilitates idea exchange and genomics cooperation; an ARS-JGC workshop is planned. We provided entomopathogens to ARS-Weslaco for research on varroa mite. With CSIRO and New Zealand’s Landcare Research we defined the taxonomic status of a dung beetle as a precondition for its introduction into Australia and New Zealand using multilocus sequencing.
Discovery of a new natural enemy of kudzu bug. The kudzu bug (or bean plataspid) is an Asian invasive species first seen in 2009 in the southeastern United States, where it is associated with kudzu. It has become an economic pest of soybeans and a severe nuisance in urban landscapes, and as of 2012 it has spread rapidly to seven states. Native U.S. natural enemies have no significant impact on the bug, and only one candidate Asian agent has thus far been identified. EBCL discovered a new species of egg-parasitic wasp from a European relative of kudzu bug which is the first known species in the genus OOENCYRTUS to attack this family of bugs. Tests with this new wasp show that it also attacks kudzu bug. Further studies with the wasp are being done in cooperation with the ARS Stoneville MS laboratory to determine its suitability as a candidate agent against the kudzu bug. If judged safe and effective, the wasp will help to control kudzu bug in the U.S.
Molecular taxonomic research supports the use of a dung beetle as a biological control agent for recycling livestock dung. After an exhaustive scientific study, an importation permit to ship and release a Eurasian species of dung beetle was issued by Australian regulators in support of a program to biologically manage accumulation of dung by livestock. However, the project was held up by questions as to the identity of the beetles collected for export. As part of a collaborative effort with researchers in Australia, New Zealand and France, ARS EBCL determined the exact taxonomic status of the dung beetle as a precondition for its introduction into Australia by using molecular genetics sequencing. Our results allowed the first introduction of this beetle into Australia to proceed, and will facilitate the continuation of Australia’s biological control program.
Establishment of an exotic natural enemy of olive fruit fly in California. Since the discovery of olive fruit fly in California a decade ago it has become the most important olive pest and threatens the economic viability of the U.S. olive industry. ARS EBCL conducted explorations for effective natural enemies of the fly in Africa and Asia. A number of agents obtained by EBCL have been evaluated by cooperators in California during the past several years, and several of these species have been permitted by APHIS for field release. Last year, after several consecutive years of releases, the recovery of one of these agents - the parasitic wasp PSYTTALIA LOUNSBURYI - was documented, indicating that it may have established. This year, further recoveries were made at a second location far from last year’s recovery, showing that establishment has likely occurred. This is the first successful establishment of an exotic natural enemy of olive fly from the fly’s native range in Africa into other regions where olive culture has spread. We anticipate that these parasitic wasps will eventually lead to significant reductions in olive fly populations as they spread throughout California.
Williams Iii, L.H., Zhu, Y., Snodgrass, G.L., Manrique, V. 2012. Plant-mediated decisions by an herbivore affect oviposition pattern and subsequent egg parasitism. Arthropod-Plant Interactions. 6:159-169. DOI 10.1007/s11829-011-9165-0.
Lee, J.C., Negron, J., Mcelwey, S., Williams, L., Witcosky, J., Popp, J., Seybold, S. 2011. Biology of the invasive banded elm bark beetle, Scolytus schevyrewi Semenov (Coleoptera: Scolytidae), in the western United States. Annals of the Entomological Society of America. 104(4):705-717.