Brown Marmorated Stink Bug


Agricultural Commissioner Sealer of Weights and Measures

Greg Clark, Agricultural Commissioner Sealer of Weights and Measures

Brown Marmorated Stink Bug

BMSB Lifestages Adult
The Brown Marmorated Stink Bug (BMSB), Halyomorpha halys, has been detected in California and Oregon. First reported in Allentown, PA around 1996, it’s suspected that BMSB was introduced from China or Japan. Since its introduction into Pennsylvania in the late 90’s, it has spread through the mid-Atlantic region of the east coast as well as in Portland, Ore., and Los Angeles.
 The Brown Marmorated Stink Bug feeds on a wide range of fruits, vegetables, and other host plants beginning in late May and early June, including peaches, apples, green beans, soybeans, cherries, raspberries, and pears. Damage is typically small necrotic areas but ranges from leaf stippling, catfacing on tree fruits, seed loss, and transmission of plant pathogens. BMSB may reach very high numbers, and since one bug can feed on many fruit, losses can be severe.

On the east coast, BMSB appears to have three generations, but in warmer climates it could have as many as six. It overwinters as an adult by hiding in leaf litter, under bark, and any other protected area it can find. BMSB travels long distances by hitching rides in vehicles or as stowaways when furniture or other articles are moved, often during winter
BMSB Lifestages
months. As a result, most new infestations are found in urban areas. BMSB can enter houses through cracks in windows and foundations and may be seen in large numbers during September and October. Due to the noxious odor produced as a defense mechanism, the stink bug is a nuisance to homeowners.


There is no state or federal detection program in place at this time, primarily because there is no commercially available trap for BMSB in the US. However, there is an attractant [methyl (E,E,Z)-2,4,6-decatrienoate] which is used in traps produced in other countries. Development of a trap for BMSB here in the U.S. is currently being conducted. The California Department of Food and Agriculture (CDFA) is tracking new finds via submission of suspected insects by county agricultural commissioner’s and state border inspection stations.


The Brown Marmorated Stink Bug is not a federally actionable pest, meaning that USDA has no federal restrictions currently in place to limit its movement. CDFA has no restrictions in place either, and has assigned the BMSB a “B-rating,” leaving all regulatory actions at the discretion of the local agricultural commissioner.

If you have any questions regarding BMSB, please contact the Agricultural Commissioner’s Office at (707) 253-4357.

Brown Marmorated Stink Bug “Unwanted” Poster