Location: Beneficial Insects Introduction Research2013 Annual Report
1a. Objectives (from AD-416):
The objectives of this project will be: 1) to identify and assess the impact and phenology of indigenous brown marmorated stink bug (BMSB) natural enemies in specialty crops; 2) to evaluate the host range and efficacy of imported Asian natural enemies of BMSB; 3) and 3) integrate biological control research findings with other management tools to form and deliver practical outcomes for stakeholders.
1b. Approach (from AD-416):
The BMSB, Halyomorpha halys (Stal), is an invasive insect native to China, Taiwan, Korea, and Japan that was introduced into the US in the mid 1990s. Damage in affected crops has now reached critical levels with some growers losing their entire crops. Preliminary research showed that native natural enemy activity against BMSB is minimal, but this needs to be verified across a broad range of habitat types. Field surveys will be conducted in conjunction with cooperators in various impacted crops and associated natural habitats to identify and quantify the impact (or lack of impact) of BMSB natural enemies in impacted regions of the U.S. In addition, imported Asian natural enemies of BMSB obtained through foreign exploration will be evaluated in quarantine to determine their host range, efficacy, and safety as potential classical biological control agents for introduction into the U.S. Natural enemies for which release permits can be obtained will be released for establishment against BMSB in conjunction with cooperators in impacted regions.
3. Progress Report:
Populations of the brown marmorated stink bug (BMSB) have developed into a significant pest in soybeans and various tree fruits in the eastern and western U.S. and are still spreading to other states. Native natural enemies of stink bugs in the US do not provide adequate suppression of populations. Therefore, foreign exploration in Asia was conducted for natural enemies of BMSB in Korea and China. Surveys included non-target species of stink bugs to document the efficacy and safety (host range) of BMSB enemies in Asia. This information will be useful in preparing petitions for field release of candidate agents in the US. Natural enemies of BMSB obtained during explorations were identified morphologically using the best available taxonomic information, and specimens were supplied to cooperators for development of reliable molecular identifications. Host range evaluation and risk assessment of exotic natural enemies of BMSB in culture was continued at BIIRU and by cooperators at universities and state agriculture departments under BIIRU direction, with tests conducted against a range of North American stink bug species. The comparative biology of the Asian natural enemies was also studied. A petition for release of the first candidate Asian biocontrol agent of BMSB is in preparation for submission to regulatory authorities. Information needed to 1) obtain permits for importation of exotic natural enemies of BMSB to the US, 2) supply these agents to co-operators, and 3) prepare, submit and revise Petitions for Release of candidate agents was also provided to project co-operators and regulatory officials. We provided technical support to cooperators for expanded sentinel surveys to monitor parasitism of BMSB by resident native stink bug parasitoids in different crop systems, including identification of specimens. During 2013 a second workshop on identification of native and exotic BMSB parasitoids (parasitic wasps) was organized to help educate research collaborators and local extension specialists. Held in conjunction with the BMSB IPM Workgroup meeting in June 2013, a total of thirty-one scientists, extension specialists and students from the US, Canada, Mexico and Switzerland attended the workshop in New Jersey. ARS researchers compiled and updated a master key for the identification of BMSB parasitoids commonly found in North America. Critical information was shared on native natural enemies of BMSB, their identification and biology, and hands-on training was provided to teach participants to identify specimens obtained in their studies. To examine the genetic diversity and identify the source region of the US BMSB introductions, cooperators sequenced portions of several genes in BMSB from populations in the US, and Asian populations from China, South Korea and Japan obtained through our foreign exploration. We observed high levels of genetic diversity in native Asian populations but very low genetic diversity in introduced US populations, and traced the origin of US BMSB populations to the Beijing area in China. A single introduction of a very small number of founding individuals explains the invasion history in the US. For effective control of the US populations, our results suggest that surveys for effective natural enemies and for evidence of insecticide resistance in native populations should focus on the Beijing area in China. The overall impact of the research is that producers will have new biological control agents available that will help them manage key insect pests by reducing chemical pest management inputs, thereby maximizing profits and sustaining yield.