The cooler weather and the stink bugs go hand in hand.
The brown marmorated stink bug was first released into the United States in Allentown, Pennsylvania, in 1996, according to Penn State University. The bug apparently traveled from northeast Asia in a shipping container that was delivered either to the port of Philadelphia or Elizabeth, New Jersey, and then trucked to Allentown.
This insect has now spread to 44 states and has very large populations in Pennsylvania, Maryland, Virginia, New York, New Jersey, Massachusetts, Delaware, Ohio, and North and South Carolina, according to stopbmsb.org. It has also spread to California and Oregon allegedly via a car driven by a person traveling from Pennsylvania to California in 2005.
According to researchers at Penn State University, this type stink bug emerges in mid- to late spring. As temperatures cool, they begin to swarm near windows, doors and other cracks of buildings seeking refuge from the coming winter. Once inside, the stink bugs enter a physiologically inactive, diapause state or state of suspended development. They emerge from this hibernation over a broad range of time, which explains why we see active adult stink bugs throughout the winter and early spring. A mass emergence from diapause occurs as daily temperatures and length of daylight increase, especially in mid- to late May.
The ability of these stink bugs to survive is quite remarkable. While there is some mortality among the hibernating bugs in the winter, a significant percentage of them make it through to spring and then mate. Colder temperatures in northern states typically reduce the bugs survival rate, but that appears to be changing.
Increasing temperatures linked to climate change are likely a cause for such an increase in stink bug populations, especially in middle and northern latitudes. While excessive heat may drive stink bugs out of hotter, Southern states, the warm but moderate temperatures at higher latitudinal locations have increased the survival of stink bugs with significantly larger spring and summer populations.
The good news is, other than being incredibly annoying and having a pungent smell, stink bugs are pretty harmless to humans and animals. They cannot bite or sting nor seem to carry any known diseases. To get rid of them, it is recommended to flush them or vacuum them, then throw out the vacuum bag to avoid the bugs' odor.
But using vacuum bags and water to get rid of these bugs could become costly, so it is best to prevent invasions by making sure you seal up your home now. Replace old screens and make sure doors and windows close tightly. Also caulk any gaps, cracks or holes in your homes exterior, especially on the south and west sides. These bugs can squeeze themselves quite a bit, so they can fit through even small cracks.
Unfortunately, these insects are quite destructive to agriculture. This species feeds on over one hundred different types of plants including several of great economic importance to humans. Fruit trees (especially apple and pear), soybeans and peanuts are significantly damaged by these insects. The bugs have also been found feeding on blackberry, sweet and field corn and have been known to cause damage to tomatoes, lima beans and green peppers.
There is no way to kill them by spraying, at least not once they are on the plant, because they must be hit directly. The bugs can fly off the leaves and they aren’t harmed by eating the chemicals on the leaves or on the fruit. However, researches at Penn State did find that while there are very few controlling natural predators, it appears other local predators such as spiders and some birds may be becoming more immune against the bug’s protective secretions and increasingly aware of the growing stink bug feast around them.
– Eric Elwell is WHIO's chief meteorologist. Contact him at firstname.lastname@example.org or follow him on Facebook and Twitter.