As the cooler weather of fall descends upon the mid-Atlantic, now seems to be a good time to revisit one of our least favorite invasive insect species… the brown marmorated stink bug. Why? If you have not noticed those nasty critters on windows and doors, trying to get into a warmer environment, either you do not live around here, your ability to see is challenged, or you are EXTREMELY lucky! To state it more succinctly… THEY’RE BACK!!!
The event that has led to the title of this entry ending with an exclamation point took place either late last winter or early spring. This may take some explaining… Here goes…
The brown marmorated stink bug for those who may not be familiar with those occasionally flying insects originated in Asia somewhere, and eventually, landed here in the mid-Atlantic around fifteen years ago. The insects have adapted well to the area and have spread throughout the region. The issue addressed here is that before the 2011 growing season, most of the Agricultural Extensive Service agents were petrified that 2011 would see an epidemic of brown marmorated stink bugs, that is, a population explosion of unprecedented scope. The damage that would be incurred by those insects could be… catastrophic!
And in 2011, I scoffed at the analysis. Since I have been farming, relatively as long as the first brown marmorated stink bug sighting on U.S. soil, I can always remember seeing them. Some years there are more and some years there are less. My main defense against any fear of a catastrophe is the birds that thrive on the farm. Birds love bugs… even stink bugs! Anyway, I was curious to see what would develop over the 2011 season, but I definitely expected NOT to see the plague that was feared…
2011 was frightful!!! Egads! There was an earthquake, extreme heat, a hurricane directly followed by a tropical storm that deluged the area so extensively that the main field was a veritable pond for a month, and then… AND THEN there was a six inch snow storm in… October… OCTOBER!!! What a crazy year!!! And amidst all of those weather extremes, as I fought through those multiple crises, stink bugs fell from my scope of importance. In fact, few brown marmorated stink bugs were witnessed during that spell of unfortunate weather events. Where were the stink bugs? I, for one, did not care since most of the crops had been ruined by the absurd weather!
Now, a year later, I suspect that some of those weather abnormalities significantly diminished the brown marmorated stink bug population since about the average number has been witnessed this year… until recently, that is. Nonetheless, now that their numbers seem to be increasing after a relatively tame year… THEY’RE BACK!
The reason the title of this entry is “Stink bug!” is because earlier this year in the late winter/early spring, I sarcastically made that statement when the first stink bug was witnessed inside the house. In 2011, something like eighty stinkbugs made it inside the house, which may be the most annoying trait of those wretched creatures. Constantly, one would start buzzing around a light fixture until, that is, it met the end of a stick I swung at it. Anyway, only about a couple dozen made it into the house this year, and my reaction was a scoff of sorts on the prediction of a stink bug epidemic…
And now it is late September. The weather has cooled significantly. As a result, the stink bugs are seeking warmer climates. Now, when cleaning the produce on the back porch of the old farm house, stink bugs can be viewed clinging to every wall and ceiling open to the outside air.
While this form of stink bug activity is normal for this time of year, I have been particularly struck by the number of stink bugs. They are everywhere. After cleaning salad mix, I paused to inventory their stock, if you will. On the back porch, there were dozens on the ceiling, posts, and walls of the summer kitchen. On the vinyl siding of the house facing south that is the warmest side, dozens of stink bugs dotted the white vinyl and clung to the window screens. As I circled the house, they were on just about every area I looked, including on every side of the CSA refrigerator on the front porch. Why the refrigerator? Why not!
After realizing that the number of stink bugs I witnessed was far greater than any other previous year, I actually felt a little nervous. If their number had increased that dramatically in one year…
“But what is the real damage stink bugs can do?” you might ask. I will tell you. Especially in organic vegetable and fruit farming, stink bugs do extensive damage. Even if a farmer grows with the use of chemical pesticides, those pesticides are often not very effective against brown marmorated stink bugs.
The main difficulty with stink bugs is that they can fly from plant to plant and their pattern of attack is extremely random. With some pests, their movements can be easily predicted and thus attacked, but, and unfortunately, stink bugs feast on so many different plants, at best, only random use of TFF is even partly successful. (TFF is my organic approach to pest control. It stands for “thumb and forefinger”, which are used to “squish” harmful bugs on sight.) The list of vegetables damaged by stink bugs is indeed extensive. These include tomatoes, peppers, beans and peas which are perhaps the worst damaged, but they also feast on just about every other crop, albeit with less damage like the broccoli/cabbage family, the chard/beet family, and many more. So now, their damage:
Tomatoes – Stinkbugs pierce a tomatoes skin and sucks out the juice. At first, this is not noticeable, then in a day or two a round sunken soft spot develops that expands greatly by the day. Organically, there is no way to prevent this other than by preventing the stink bug bite in the first place, which as mentioned above, is a random attack and virtually impossible to defend. My approach is to attract as many birds as possible to help in the fight. The conventional farm will most likely dust the tomatoes with the known carcinogen Sevin, which for the most part keeps the stinkbug from landing on the tomatoes… and in the long run leads to cancer.
Peppers – Stinkbug attacks on peppers are very much like that of their cousins, the tomatoes. Again, there is little one can ultimately do to prevent them organically, other than attract their predators, birds.
Beans- The damage on beans is less obvious than tomatoes and peppers, but it does cause discoloration and premature matter break down. The main frustration for the organic farmer is that often when the beans, and for that matter the tomatoes, peppers and peas, are harvested absolutely no damage is visible. It is only the next day or two that the damage reveals itself. Despite the freshness of the harvest, it often leads to quite a short “shelf life”.
Peas – Peas experience the same damage as beans.
As for the other plants, say chard, there will be a hole or black spot on the leaves that do not spread as much as on the juicier fruit of tomatoes and peas. This damage is relatively easy to overlook… and forgive. And, since I do not have enough experience with fruit at this point, I will not relay the damage they cause on those crops, only to say that a fruit farmer friend of mine has relayed that entire apple crops can be ruined by stink bugs.
After all that… is there a brown marmorated stink bug plague in the near future? The answer to that is that I do not know. However, one more quick story will relay how nature loves to balance things out. The other day, I was washing salad mix again, and heard a banging commotion on the house siding above. Since the back porch is an overhang, I had to lean out off the porch edge and look up. What was the commotion? Birds swooping in to gobble up the stink bugs clinging to the siding! It was quite an impressive display. A day later, it was obvious that the stink bug numbers had been greatly diminished.
I do realize it would be completely naïve to think that birds could “rid” the farm of the stink bug populace. Nature does love balance after all. Even after watching the bird feast, I still expect for there to be quite a few more brown marmorated stink bugs next year, and that is a reality that will have to dealt with accordingly. Like it or not, brown marmorated stink bugs are most likely here to stay.