Brown marmorated stink bug (BMSB) overwinters as adults in a protective sleeplike state, emerges in the spring, and begins mating in about two weeks. BMSB commonly mates multiple times, and the female may deposit as many as 486 eggs in a lifetime. Development from egg to adult requires approximately 538 degree days, a measure of temperature and time for insect growth, with an additional 148 degree day period before eggs are laid. Its light-green eggs are often laid on the underside of leaves, deposited in masses of approximately 28 eggs.
|From left to right, four nymphal stages of BMSB (second through fifth instar), adult male, and adult female. Photo by W. Hershberger|
|BMSB nymphs, first instar, cluster around a mass of newly-hatched eggs on the underside of a leaf. Photo by W. Hershberger|
|Adult BMSB on an apple. Photo by W. Hershberger|
While the adults blend in with tree bark, the nymphs are more brightly colored. BMSB has five nymphal stages ranging from 2.4 mm to 12 mm in length. Early-stage nymphs do not venture very far from the newly hatched egg mass. The legs and antennae of nymphs are black with white banding. Early-stage nymphs have dark reddish eyes and a yellow-reddish underbelly with black stripes.
BMSB may be able to produce several broods in a single year, thus increasing the potential and duration of risk for crop damage. Our research team is seeking to understand the unusual overwintering behavior of the stink bug, as it is believed to move readily among woodlands, buildings, and farmland.
 H. Kawada and C. Kitamura, 1983, “The reproductive behavior of the brown marmorated stink bug, Halyomorpha mista Uhler (Heteroptera: Pentatomidae). I. Observation of mating behavior and multiple copulation.” Applied Entomology and Zoology 18: 234-242, via Tracy Leskey et al, 2011, “Biology, ecology, and management of brown marmorated stink bug in orchard crops, small fruit, grapes, vegetables, and ornamentals: USDA-NIFA SCRI coordinated agricultural project.” USDA-ARS Appalachian Fruit Research Station. For more information about the SCRI project proposal, contact project director Tracy Leskey.
 A.L. Nielsen, G.C. Hamilton and D. Matadha, 2008, “Developmental rate estimation and life table analysis for Halyomorpha halys (Hemiptera: Pentatomidae).” Environmental Entomology 37: 348-355 via Leskey et al. 2011.
 K. Kiritani, 2006, “Predicting impacts of global warming on population dynamics and distribution of arthropods in Japan.” Population Ecology 48: 5-12 via Leskey et al. 2011.
 K. Kiritani, 2007, “The impact of global warming and land-use change on the pest status of rice and fruit bugs (Heteroptera) in Japan.” Global Change Biology 13: 1586-1595 via Leskey et al. 2011.
 Leskey et al. 2011.