Is Halyomorpha halys (Hemiptera: Pentatomidae) a threat to California rice?

The brown marmorated stink bug Halyomorpha halys (Stål), is an invasive pest in California that represents a potential threat to California rice (Oryza sativa L.) production. Populations of H. halys can be found in the rice production regions of California but have not been detected in rice fields. We conducted greenhouse trials to determine if H. halys injures and potentially reduces yields in rice. We observed a 42% reduction in kernel weights during the milk stage in cages with H. halys adults in 2014. We observed a 30% increase in empty kernels in rice infested with H. halys and a 10-20% increase in pecky rice across various rice maturation stages in 2016. The results suggest that yield reductions in rice could occur if H. halys establishes on rice as a host plant in the United States. This is the first reported case of H. halys being able to feed on rice in North America.