Why Stink Bugs Are Taking Over the Eastern United States

Photo: Halyomorpha halys, Gary Bernon, USDA-APHIS
Photo: Halyomorpha halys, Gary Bernon, USDA-APHIS

If you live anywhere near the Eastern United States, you’ve probably noticed an increased number of stink bugs over the past few years.

Known by scientists as “Halyomorpha halys“, the brown marmorated stink bug is an insect native to China, Japan and Taiwan that was accidentally introduced into the United States in the late 1990s and has quickly become a serious pest to farmers, homeowners and the fragile eco-system of the Appalachian Mountains.

The bug, which receives its name for its ability to emit an odor through holes in its abdomen when it feels threatened or attempts to find a mate, invades homes in the fall in order to hibernate through winter; however, once inside, the warmth inside houses often causes them to become active during their winter hibernation — leading the invasive bug to fly clumsily around light fixtures.

The bugs are believed to have illegally entered the United States after hitching 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 the brown marmorated stink bug at shipping ports in the United States.

By 2009, the bug had reached Maryland, West Virginia, Virginia, Tennessee, North Carolina, Kentucky, Ohio, Illinois, and Oregon.

As of 2010, seventeen states had been categorized as having established brown marmorated stink bug populations.

Currently, stink bug populations are on the rise because the climate in the United States is ideal for their reproduction. In optimal conditions, an adult stink bug will develop within 35 to 45 days after hatching.  Female stink bugs are capable of laying four hundred eggs in their lifetime and the bugs are capable of producing at least one successful generation per year in all areas of the United States, no matter the climate. In warmer climates, multiple generations can occur annually.

In addition to becoming an additional pest for homeowners left to deal with, the brown stink bugs have become a serious threat to the nation’s agricultural community, as they feed on a wide array of plants including apples, apricots, Asian pears, cherries, corn, grapes, lima beans, peaches, peppers, tomatoes, and soybeans.

Their ability to sustain themselves upon a vast array of plants makes them extremely versatile as they do not require a specific plant to feed on.

Making stink bugs an even greater concern is the fact that the extremely mobile insects have no natural predator in America and the bugs are beginning to show signs of developing a resistance to pyrethroid insecticides, a common chemical used to combat infestations.

In Asia, a parasitoid wasp species known as the japonicus serves as the bugs’ primary predator; however, the wasp is not currently present in the United States.

Studies are presently underway reviewing the effects of introducing the wasp into the county, but this generally believed to be a bad idea due to the fact that japonicus wasp will also become an invasive species with no native predators. Before introducing the Chinese wasp, scientists are trying to find natural predators of the stink bug already present in the United States.

Researchers have also experimented with different spider species as well as the Wheel bug. Several spider species attacked both the eggs as well as live stink bugs in clinical studies.

The bottom line is this: as bad as the brown marmorated stink bug is becoming, the remedy may be worse than the disease… unless you’re a fan of vicious Asian wasps or spiders… lots of spiders!

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  1. I have these things inour home at times and myfriends homes as well . When you say the Remedy may be worse than the Disease, what does that mean. Do these things carry a disease that we can catch. Or are you referring to the Disease upon our Ecosystem. I hate these things, they are aggrivating but if rather deal with them and kill them as versus having more insects and bugs brought into our Country from Foreign land that will harm us just to control them.

    • They are referring to the wasp or spiders being introduced as the remedy to getting rid of the stink bugs.

    • Seriously? It’s a phrase, figuratively meaning, the solution or proposed solution to a problem produces a worse net result than the problem does. The author did not mean a literal disease.

  2. Asian wasp, enemy of stink bugs, found
    in the United States

    One of the recovered Beltsville specimens of Trissolcus japonicus emerges from a BMSB egg. Source: Elijah Talamas, USDA Agricultural Research Service, Systematic Entomology Laboratory
    One of the recovered Beltsville specimens of Trissolcus japonicus emerges from a BMSB egg. Source: Elijah Talamas, USDA Agricultural Research Service, Systematic Entomology Laboratory
    The Asian wasp Trissolcus japonicus has been found in the wild in the United States. The wasp, native to the regions of Asia where the brown marmorated stink bug (BMSB) originates, is known to attack the eggs of BMSB and possibly other stink bugs. The wasp doesn’t sting or otherwise harm humans, but scientists are working to determine how it might affect stink bugs of all kinds. Kim Hoelmer, an entomologist with the USDA Agricultural Research Service, wrote:

    “A survey of resident egg parasitoids of the brown marmorated stink bug, Halyomorpha halys, conducted during the summer of 2014 by Megan Herlihy and Don Weber (ARS-Beltsville Area Research Center, or BARC) using sentinel stink bug egg masses revealed that an Asian egg parasitoid of BMSB, Trissolcus japonicus, was present in the wild at one of his study sites at BARC in Beltsville, Maryland. The specimens were identified by Dr. Elijah Talamas (ARS, Systematic Entomology Laboratory, or SEL), a specialist on this group of parasitoids. We have complete confidence in his identifications. The identification was confirmed by Dr. Matt Buffington (also ARS-SEL) using genomic DNA. The ‘barcode’ regions COI and ITS2 of the BARC specimens were consistent with those of Asian populations of T. japonicus obtained from ARS and CABI-Bioscience field collections in Asia and analyzed by Dr. M.C. Bon at the ARS European Biological Control Laboratory.

    StopBMSB.org provides information about our team’s efforts to control brown marmorated stink bug (BMSB), through funds provided by the USDA’s Specialty Crop Research Initiative. If republishing our news, please acknowledge the source (“From StopBMSB.org”) along with a link to our website.

  3. I do not understand or agree with this statement: “The first documented specimen was collected in Allentown, Pennsylvania, in September 1998.” I am 58 years old and absolutely remember these bugs from when I was a young child. Never saw but maybe half a dozen in my whole life up until a few years ago, but we DID see them way back then. These bugs have been around a long time and anyone that tries to tell me different I am going to call them crazy as a stink bug!

    • The third word here is key to the truth of the statement. Did you document (photograph, report, collect specimens of) these guys back in the day? If not the writing/statement is correct even if your memory is evidence for you of the contrary. I am of course not in a position to say that your memory is correct or incorrect as it is possible that you came across the little pests earlier than when they were documented.

      • Jeff Houston is 100% correct. I am from West Virginia and have seen thousands of Stink Bugs during the 1970s and 1980s. I picked Raspberries and Blackberries and these vines were and are still covered with these bugs. On many occasions I have had them fly into my mouth and they taste like chemicals.

    • There are several stink bugs and similar insects that are native to the US. The 1998 date refers specifically to the brown marmorated stink bug (Halyomorpha halys), which is an invasive species native to Asia.

  4. Our solution is to make traps from small soda bottles (saw this in a magazine). Cut top portion of soda bottle off and (will have to decide how to cut it so it doesn’t fall into the bottom) invert into the bottom, then tape the two pats with duct tape or packing tape. You can scoop the bug off surface with bottle and it falls into the bottle and an not get out and dies. We also tape one on a yardstick so we can scoop off of ceiling. We have really seen a difference in the amount of stink bugs we have seen this year. SIMPLE but it does work!!!

  5. They started here around 2011 , i have woods all around my house and i think i get more than most people
    i kill ten to fifteen a night. can’t stand them . i know they will not hurt you, but i am scared of them because they are creepy. i tried that bottle thing, not helpful

  6. Get thousands not hundreds.. Can’t even sit outside in the fall there flying everywhere..It’s sad ..pa fall weather is beautiful….. Can’t freaking believe those stinking annoying bugs invaded or states

  7. They’re attracted to the odor they release as well. So when removing them try not to “scare” them as more will come. I drop careful drop them in a cleaning solution and they die instantly.

  8. Here in swPA I have watched Carolina Wrens, Blue Jays, and Mockingbirds eat them. Wrens especially. They even tried to get at ones who were trapped in Eva’s insect viewing jar. Also spiders on my porch have caught and eaten them.

  9. Nasty and make sure when putting on coats that have been hanging in the garage to shake as they clink to any dark places. We also have those look alike lady bugs that are driving us crazy with cathedral ceilings.

  10. I remember stink bugs when I was growing up, 1970’s-80’s. Those bugs had a foul smell when you killed them. The ones I’ve seen over the past few years do not have a foul smell when you kill them. These may be two different insects.

  11. We use a “Bucket Head” (small sop vac) from Home Depot for large numbers. Put some water in the bucket with a few drops of soap, then vacuum them up in this easily portable kit. The soap breaks the water’s surface tension and they drown quickly. For smaller numbers in the house, we use a plastic cup with a little water and soap. If they congregate on your outside walls in the Fall, you can get a spray that works for weeks from Southern States. I don’t remember the name, but they certainly will.

  12. I cannot stand these bugs! They stink and drive me nuts! So I got this off the internet: Take an empty 32 oz spray bottle, fill it with 1/4 cup dish washing detergent and add 10 drops of peppermint flavoring(or any of the mint flavorings), mix well. Spray your door and window frames well. They won’t come in so much. As well, I put a small amount into a disposable cup and scoop them into it. They hate the mint odor(but it makes your house smell better!) and avoid it. The detergent coats their exoskeleton and they can’t breath, so they die. This has really worked well for me. Thank God!

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