Published by Utah State University Extension and Utah Plant Pest Diagnostic Laboratory
ENT-198-19
October December 2022
Parasitoid Wasps of the Invasive Brown Marmorated Stink Bug in Utah
Zachary R. Schumm • Kate V. Richardson • Mark Cody Holthouse • Yota Mizuno • Diane G. Alston • Lori R. Spears
Do You Know? • In 2012, brown marmorated stink bug (BMSB), an invasive insect pest from eastern Asia, was first detected in Utah in Salt Lake City. Beginning in 2017, it has caused agricultural damage in northern Utah. • There are few natural enemies of BMSB, allowing populations to increase when unchecked. • Parasitoid wasps that sting and kill stink bug eggs show promise as a biological control method. Native parasitoid wasps in Utah have been ineffective against BMSB to date.
While crop damage to peach, apple, squash, and popcorn has been observed, it is currently causing mostly nuisance problems due to overwintering adult bugs on and within human structures. Adult BMSB are marbled brown and black, camouflaging well with woody vegetation. To separate this stink bug from native look-alikes, notice the characteristic white bands on their antennae. Native stink bug species do not have this feature. BMSB also has smooth shoulders and a black/white pattern on the edge of the abdomen (Fig. 2).
• Samurai wasp, the primary parasitoid of BMSB in eastern Asia, was detected in Utah in 2019; this wasp shows promise for BMSB suppression. The brown marmorated stink bug (BMSB, Halyomorpha halys Stål) is an invasive agricultural and nuisance pest native to eastern Asia. It was first confirmed in the U.S. in Allentown, PA, in 1996 and has since spread to 47 U.S. states and 4 Canadian provinces, many of which have now experienced economic crop damage from this pest (Fig. 1). In Utah, BMSB is now established in six counties (Box Elder, Cache, Davis, Salt Lake, Utah, and Weber), with detection in Carbon and Kane counties.
Fig. 2. A BMSB adult with quick identification characteristics. The white bands on dark antennae is the most helpful feature.
BMSB is a successful invasive for a number of reasons: it is polyphagous (feeds on many plant types), highly mobile, has few natural enemies, and adults have a tough exoskeleton that is covered in a waxy, water-repellent cuticle that helps protect them from pesticide applications and the environmment. Biological control, through the use of egg parasitoids, is the most suitable option for long-term management of BMSB.
GENERAL PARASITOID INFORMATION Fig. 1. The current distribution and status of BMSB in North America as of March 2021. For updates, see http://www.stopbmsb.org/where-is-bmsb/.
UPPDL, 5305 Old Main Hill, Logan UT 84322, utahpests.usu.edu
There are at least two families of stink bug parasitoids in Utah, Eupelmidae and Scelionidae. These are small, typically black wasps that may be mistaken for small gnats or ants. They will fly in search of stink bug egg masses. Once they find the eggs, they will sting them, depositing one of Page 1