The Asian wasp, Trissolcus japonicus, has been identified in the wild at a study site in Beltsville, MD. This wasp originates from the same region as the brown marmorated stinkbug (BMSB) and preys on the eggs of those insects along with other stinkbugs. While this wasp isn’t known to sting or hurt humans in any way, research is ongoing to determine its effect on stinkbug populations.
T. japonicus has been studied in quarantine facilities in the US since 2007, following the United States Department of Agriculture’s Agricultural Research Service’s (USDA ARS) foreign exploration and import under an Animal and Plant Health Inspection Service (APHIS) permit to evaluate its value as a biological control and host specificity for native and exotic stinkbugs. To-date, research results indicates that while BMSB is the preferred host for T. japonicus the wasp is able to target other species of stinkbugs, but does not develop comparable parasitism rates as with BMSB.
Continued research will focus on the influence of environmental factors for host preference. How T. japonicus arrived in the wild of Maryland is unknown and considered accidental as no researchers are currently working with the species in that area. The most likely scenario for their arrival is within parasitized stinkbug egg masses adhering to ornamental plant imports.