Utah Pest News Winter 2011

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Invasive Pest Highlight:  The Brown Marmorated Stink Bug

A new invasive pest to the U.S. is a concern for Utah’s agricultural, landscape, and home garden industries. The brown marmorated stink bug (Hemiptera: Pentatomidae) is native to Asia and was first detected in the U.S. in Allentown, Pennsylvania in 1998. It has since spread to areas of the Mid-Atlantic, South-Atlantic, Northeast, Great Lakes, and Northwest regions of the U.S. In 2010, it caused severe crop injury to pome and stone fruits and some small fruits and vegetables in the Mid-Atlantic region. Some characteristics of the brown marmorated (= marbled) stink bug that make it such a concern include:

  • Adult populations move rapidly from one crop to another (a few hours for nearby fields).
  • It appears to be widely adaptable to many regions of the U.S.
  • It has a broad plant host range that includes tree fruits, vine and cane fruits, some vegetables (sweet corn, tomato, pepper, bean, asparagus), some field crops (soybean, corn), and some landscape trees and shrubs.
  • It feeds on fruits, seeds, and leaves.
  • It is already showing resistace to some pyrethroid insecticides.
  • Both the adult and nymph (immature) stages cause plant injury.
  • It is also a nuisance pest, as it seeks shelter from the winter within buildings (similar to boxelder bug and the Asian multicolored lady beetle). 

  Adult stink bugs (top left) are identified by white bands on dark antennae, a smooth "shoulder" and black and white pattern around abdomen.  Eggs and nymphs (top right) are difficult to tell from other stink bugs. Injury to apple fruit(bottom) resembles other stink bug injury.


Oregon State University is recommending that sweet cherry growers reduce SWD populations in the early season with insecticides.  Utah fruit producers applying insecticides for other insect pests, such as cherry fruit fly, raspberry horntail, or peach twig borer, should consider using insecticides with activity against SWD in case the insect is present.  Cherry fruits become susceptible to SWD beginning at light straw color; slightly less mature than when they become susceptible to cherry fruit fly.  Insecticides with documented efficacy to SWD include acetamiprid (Assail), spinetoram (Delegate), spinosad (Entrust, Success), imidacloprid (Provado), carbaryl (Sevin), malathion (Malathion), azinphosmethyl (Guthion), and most synthetic pyrethroids.  Avoid overuse of pyrethroids, malathion, and carbaryl as they can flare spider mites.  Rotate chemical types and be mindful of re-entry intervals (REIs), pre-harvest intervals (PHIs), and maximum residue limits (MRLs) when selecting products to use.


The adult is a typical shield-shaped stink bug (5/8 in long, 3/8 in wide). Its upper side is mottled brown and gray and its underside is white with gray and black markings. Its antennae have alternating dark and light bands on the last two segments which is a characteristic that separates it from other similar-looking stink bugs. Adults and nymphs have red eyes. Nymphs are oval-shaped and tick-like in appearance. Early nymphs are yellowish brown and mottled with black and red. Late nymphs are darker with light bands on dark legs and antennae. Eggs are light green, barrel-shaped and laid in small clusters (20-30 eggs). The brown marmorated stink bug generally completes one generation per year in most regions of the U.S., but it may be multi-voltine in warmer areas. It overwinters in the adult stage. Adults seek protected sites beginning in September. This habit causes it to be a nuisance pest for people as it congregates in homes, office buildings and other structures.


Utah crop producers and home gardeners should be on the look-out for this insect to show up in Utah. It is now well established in greater Portland, OR. It could easily be transported on plant products or in vehicles to the fruit and vegetable producing regions of Utah. If a suspected specimen is spotted, collect it and submit it to your local Utah State University Extension office or Utah Department of Agriculture and Food office. Also report any suspect plant injury as this has been a common way its presence has been first detected in other regions of the country.

-Diane Alston, Entomologist



For further information, visit these online resources:

Penn State Extension Brown Marmorated Stink Bug Fact Sheet

Ohio State Brown Marmorated Stink Bug Fact Sheet

Oregon Dept. of Agriculture Brown Marmorated Stink Bug Pest Alert