B rown marmorated stink bug (BMSB), Halyomorpha halys (Stål) (Hemiptera: Pentatomidae), has a native range that includes China, Japan, Korea and Taiwan. Its host plant range extends to more than 170 species, among which are valuable ornamentals and agricultural fruit, nut and vegetable crops (Lee et al. 2013;Rice et al. 2014). BMSB can cause direct injury to crops while using its piercing-sucking mouthparts to feed. Characterization of feeding injury to marketable crops such as surface discoloration, depressed areas, deformation or abortion of fruit bodies and internal tissue damage can vary by crop (Rice et al. 2014). BMSB was first detected in the United States in 1996 in Allentown, Pennsylvania. Since then, BMSB has been detected in 42 U.S. states, with establishment (reproduction) confirmed in at least 26 states where nuisance and/or agricultural problems associated with its presence and ensuing economic losses to crops have been reported (NIPMC 2015).Crop losses from BMSB and aggregations in human-made structures have been significant in the eastern United States, where BMSB first established (Rice et al. 2014). The establishment of BMSB in this region confirms its tolerance to climates outside of its home range. Field and laboratory research is needed to characterize the degree to which BMSB can tolerate temperature stresses (i.e., winter cold and summer heat) and how this may influence population dynamics in other geographic locations within the United States (Cira et al. 2016). In addition, the invasion process of BMSB in the United Online: http://californiaagriculture.ucanr.edu/ landingpage.cfm?article=ca.v070n01p15&fulltext=yes doi: 10.3733/ca.v070n01p15Mike Lewis BMSB adult feeding on kumquat fruit. In California, BMSB populations are found mainly in urban locales, but there is risk they will move into agricultural areas.