Although we are in the midst of winter, I keep finding active individuals of a pest known as the Brown Marmorated Stink Bug (BMSB) popping out of nowhere, or anywhere! Just yesterday, as I was pulling sheets out of a drawer, I found one of these non-native invasive insects amongst the folds. While I felt like I had a fairly good grasp on the story of the BMSB in our area, I decided to do a little research to find out what the increasing populations of this bug means for us in Central Kentucky. It turns out that I didn’t know quite a bit of its story and what I’ve discovered is that this critter may have some fairly significant impacts on our region.
The BMSB, native to Asia and now a commonly recognized household pest of North America, was first officially reported in the U.S. in 2001 in Allentown, PA (Hoebeke and Carter 2003). Today it is believed that this Asian stink bug has been reproducing in and around that area of Pennsylvania since 1996. Populations most likely went undetected until 2001 because they were not large enough to be a nuisance or cause significant damage to surrounding crops.
Like many bugs, the BMSB must go through multiple developmental stages, or instars, before they reach their recognizable adult stage. This gradual transformation can initially make identification difficult, but once you know what you’re looking for, you should have no problem identifying all stages of this insect’s life. First instar nymphs (those just hatched) show a black head, red or orange abdomen, with black stripes. Second instar nymphs are larger, more closely resemble the body shape of the adults, and are mostly black all over. Third, fourth and fifth instars more closely resemble the coloration of the adult stage.
Since 2001 the population range of the BMSB has slowly but steadily increased. This pest has been discovered in several U.S. states from New Hampshire to Georgia with established populations in states such as Kentucky, Ohio, Indiana and Tennessee.
So does it matter that this bug is here? That really is a good question to ask. Numerous species of plants and animals make it across our boarders from all over the world, and really only a handful of those (though that number is growing) ever cause economic or ecological harm. The answer, in regards to the BMSB, is yes, it is a threat. Currently this pest is more of a household and ornamental problem. However, there is the very real potential that as the population of this pest grows its impacts on our agricultural industry will grow as well. Some of the preferred foods of the BMSB include our favorite fruit crops (apple, pear, peach, raspberries, grapes…), vegetables (green beans, peppers, asparagus), and main agronomic crops (soybean, corn); not to mention many of our native trees (basswood, serviceberry, walnut, maple…). And for us tree lovers, having to watch for one more damaging insects on our trees can become dis-heartening.
That said, to this point the BMSB has yet to exceed manageable population thresholds. The more aware we as homeowners and nature lovers are about the types of insects to watch out for in our gardens, the more help we can be to the agencies tasked with keeping outbreaks of such pests under control. There are no current methods for eradicating this pest just yet, but this bug is still ‘young’ in the grand scheme of the ecology of our system.