Every year during the onset of both autumn and spring, we see a rise in the local stink bug population here in the United States, particularly in the states along the east coast. And sometimes we can even spot them on mild days in December. (Thanks to global warming, we can add stink bugs to the list of global catastrophes such as melting glaciers, rising tides, and an increase in hurricanes.)
Indeed, the stink bug problem has been increasing over the course of the past couple of decades since they first arrived in North America, and many pest control companies, and even local, state, and federal government agencies such as the US Department Of Agriculture (USDA) and the Environmental Protection Agency (EPA) have been quite busy researching and tackling the issue.
Yes, believe it or not, the problem of stink bugs has made it to the list of priorities for the United States federal government to tackle, so you can be rest assured that our tax dollars are hard at work trying to deal with the stink bug crisis. (I use the word crisis here because the problem has grown out of control and is no longer a mere, localized problem, but is an actual crisis, due to the economic and environmental threat that stink bugs pose to the agricultural industry, being that these bugs feed exclusively on fruits and vegetables only.)
Entomologists (people who make it their business to study insects) are assessing different means to curb the rate of their population growth, exterminate them, or at the very least, keep them away from our food crops. Being that stink bugs are not indigenous to the North American continent, they were never part of the evolutionary history of this part of the world, and therefore, they have no clearly defined place on the food chain. They have no known natural predators in the wild and they themselves do not hunt other insects either.
In a balanced ecosystem, you will always have a proportionate number of predators and prey, so as to keep the population of various species at sustained levels. It is when either the predator or the prey are outnumbered that an imbalance occurs and one particular species can become “endangered” or “extinct”.
So while much attention is being paid to the various ways how to exterminate stink bugs, attention is also being focused on how to keep the rate of stink bug population growth in check, or to even slow it down, using natural means (as opposed to artificial means). Therefore, a close look is being paid on what, if any, predators the stink bug may have.
Unfortunately for us humans (but fortunately for the stink bugs themselves), mother nature has granted them with a very clever self-defense mechanism: the weapon of stink (hence the name “stink bug”). Much like skunks that give off noxious odors when they are attacked or threatened, stink bugs also give off a noxious odor whenever they are attacked or threatened as well. And this is usually enough to drive off any animal or human who tries to come near it. The smell is repugnant enough to give the bug enough time to escape and make it to safety.
Even those animals who try to eat stink bugs will most likely end up spitting them out, because they would no doubt taste just as bad as they smell. (Never mind the fact that many people claim that the stink bug odor smells awfully similar to cilantro.
So if there are no animals or insects in the wild that are willing to hold their noses and eat stink bugs, then how is their population growth not being kept in check, particularly in their native land of southeast Asia where they are originally from? (Apparently the stink bug problem in that part of the world, while it is prevalent, isn’t exactly growing out of control at epidemic proportions the way it is here in the United States.)
The good news is that one potential predator has in fact been found: The parasitoid wasp.
It is not a predator of live stink bugs per se. They don’t capture, kill, and eat living, adult stink bugs. Instead, the wasp has been found to feed on the unhatched eggs laid by stink bugs. (For those of us who are vegetarians who won’t eat grown chickens, but are perfectly fine with eating eggs, it’s the same idea here.)
So let’s say you were to put a wasp, a stink bug, and a nest of stink bug eggs all in the same glass tank. You would find that the wasp would ignore the stink bug and eat its eggs. The stink bug on the other hand won’t eat the wasp, because it only feeds on fruits and vegetables. Will the stink bug defend its eggs by attempting to spray the wasp? That’s another story. If you want to try this at home, feel free, and then drop us a line with your comments to let us know! If our editors like your story, perhaps we’ll post it.
Many state governments across the United States are experimenting with an interesting idea. Let’s take a look at this one example from the Oregon Department of Horticulture:
They are importing a limited quantity of trissolcus halyomorphae, a species of parasitoid wasp found exlusively in Asia. What this wasp does is quite literally hijack stink bug eggs by injecting their own eggs into those of the stink bug. The result is that a wasp will be born, instead of a stink bug. Wierd huh?
Interesting that the only known species of stink bug predators, which are alien to North America but are native to Asia, is another insect which is also alien to North America and happens to be a native of Asia. (This is like saying that the only person who could defeat Superman, a native of the planet Krypton, would have to be another person from Krypton, such as General Zod. But I digress.)
The intended outcome is to prevent further stink bugs from being born and allowing existing stink bugs to die off, thus slowing down the rate of their population growth altogether.
Will this solution work? Only time will tell. In the meantime, the clock is ticking, as these little buggers are wreaking havoc on the American agricultural industry, destroying our crops, which means millions of dollars in lost revenue each year. According to this study done at Virginia Tech, 20% of all crops were lost due to stink bugs in northern Virginia in the year 2010. This is just a representative sample of the amount of damage these insects have caused.
Stink bug predators out there, please come forward! We need you!