<P> The odor from the stink bug is due to trans - 2 - decenal and trans - 2 - Octenal . The smell has been characterized as a "pungent odor that smells like coriander ." The stink bug's ability to emit an odor through holes in its abdomen is a defense mechanism meant to prevent it from being eaten by birds and lizards . However, simply handling the bug, injuring it, or attempting to move it can trigger it to release the odor . </P> <P> During courtship, the male emits pheromones and vibrational signals to communicate with a female, which replies with her own vibrational signals, as in all stink bugs . The insects use the signals to recognize and locate each other . Vibrational signals of this species are noted for their low frequency, and one male signal type is much longer than any other previously described signals in stink bugs, although the significance of this is not yet clear . </P> <P> The brown marmorated stink bug was accidentally introduced into the United States from China or Japan . It is believed to have hitched a ride as a stowaway in packing crates or on various types of machinery . The first documented specimen was collected in Allentown, Pennsylvania, in September 1998 . Several Muhlenberg College students were reported to have seen these bugs as early as August of that same year . Between 2001 and 2010 there were fifty - four reported sightings of BMSB at shipping ports in the United States . However, stink bugs are listed as non-reportable, meaning that they do not need to be reported or have any required action taken to remove the insect . This allowed the insect to enter the United States relatively easily as they are able to survive long periods of time in hot or cold conditions . </P> <P> Other reports have the brown marmorated stink bug recovered as early as 2000 in New Jersey from a black light trap run by the Rutgers Cooperative Extension (RCE) Vegetable Integrated Pest Management program in Milford, New Jersey . In 2002, it was again collected in New Jersey from black light traps located in Phillipsburg and Little York and was found on plant material in Stewartsville . It was quickly documented and established in many counties in Pennsylvania, New Jersey, Delaware, Connecticut and New York on the eastern coast of the United States . By 2009, this agricultural pest had reached Maryland, West Virginia, Virginia, Tennessee, North Carolina, Kentucky, Ohio, Illinois, and Oregon . In 2010 this pest was found in additional states including Indiana, Michigan, Minnesota, and other states . As of November 2011 it had spread to 34 U.S. states and by 2012 to 40 and showed an increase of 60% in total numbers over 2011 . </P>

Where did all of the stink bugs come from
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