2012 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)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.
We maintained a robust colony of BMSB year-round to support the host range studies, and distributed information on rearing methods to various cooperators. We also provided live BMSB adults to several cooperators to help them establish research cultures. We collected a variety of native pentatomids in the field and initiated colonies of 16 species to support the host-specificity testing. We provided information to cooperators to help them apply for interstate shipment permits to receive exotic BMSB agents from ARS Newark’s quarantine. We sent a supply of BMSB eggs parasitized by T. halyomorphae to Florida and Oregon state cooperators and an ARS Stoneville MS cooperator to help them establish research cultures. Progress continued on host specificity testing already underway at the ARS BIIR Newark laboratory. We continued no-choice & initiated choice testing on egg masses obtained from a variety of resident stink bug species collected locally and exposed to the Asian Trissolcus species in our quarantine.
We continued a 7-year survey for native natural enemies attacking BMSB on trees and shrubs in the mid-Atlantic states. Trends in native natural enemy impact have not changed over the course of the study and continue to show very low levels of parasitism in this environment. No new native parasitoid species were identified that had not already been seen in previous years’ surveys.
Foreign exploration in Asia has already resulted in the discovery of several candidate species of BMSB natural enemies that are now maintained in laboratory cultures at our Newark ARS laboratory, where they are being evaluated to determine their efficacy and host range under quarantine rearing conditions. During August 2012 the PI visited Korea and Japan to meet stink bug researchers in these countries and collect additional BMSB parasitoids. Natural enemy host range evaluations were continued by testing a representative group of non-target species. We are also rearing several native BMSB parasitoid species here in Newark for comparative studies of the efficacy of exotic and native parasitoid species and their potential interactions (interference competition, etc.).
To conclusively identify the Asian BMSB parasitoids, we initiated research in collaboration with the ARS European Biological Control Laboratory to develop molecular “barcode” primers that will help to determine the number of different species and identify the presence of cryptic species, and with the ARS Systematic Entomology Laboratory to make necessary taxonomic revisions of the genus Trissolcus, to which these species belong. We also worked with the Systematic Entomology Laboratory and the Oregon State Department of Agriculture Imaging Laboratory to obtain high-resolution photographs to illustrate morphological characters useful for species identifications. Reliable identifications help us to ensure the purity of our research rearing cultures and will be required for eventual petitions for field release of candidate biological control agents.
Our outreach activities for this agreement include (1) development of protocols for field surveys to measure the occurrence of, and impact of, parasitism for use by researchers at other locations, provision of laboratory cultures and rearing techniques and protocols to other researchers to start their own research colonies of BMSB and natural enemies, and (3) assistance in identifying the species of natural enemies that attack BMSB, especially parasitoid wasps. During spring of 2012 we sponsored a workshop in Newark for project cooperators on the identification of BMSB parasitoids. Twenty-four researchers and graduate students from across North America attended. They received identification keys for natural enemies and practiced making identifications using unknown specimens. Participants thought the workshop was useful, and there is considerable interest in repeating the workshop at a later date to accommodate those who were not able to attend this one. Information presented at the workshop will also be posted on the NE IPM BMSB website.