Eradicating Stink Bugs!

Lee Royer
Frederick County Master Gardener

The only thing most people really want to know about stinkbugs is how to get rid of them. Donít get your hopes up, but that will be discussed shortly. Specifically we are talking about the invasive Asian stowaway, Brown Marmorated Stink Bug (BMSB), Halyomorpha halys Stal. Infamously, when disturbed or squashed, stink bugs release a defensive foul smelling liquid from glands between their first and second pair of legs. Even newly hatched nymphs have stink glands. The smell is annoying, but their eating habits are the real problem. Using a proboscis (mouth part) they pierce plant or fruit, inject digestive enzymes which liquefy the tissues, then suck out the liquid nutrients. In fruit, this creates a scar called a dimple which is unsightly, often not marketable, and increases potential for rot. Large infestations will kill host plants, even trees.

Homeowners are dismayed but farmers and commercial growers are taking serious hits. Brian Biggins of Miolea Organic Farm, Adamstown, reported a total loss of both peppers and late season sweet corn in 2010. Two factors make BMSB more devastating than previous invasive insects. First is their extraordinarily wide variety of host plants and second, all five nymph instars (developmental stages) feed on the same assortment as adults. Serious damage was reported in 2010 on apples, peaches, pears, soy beans, corn, wine grapes, berries, filberts, many vegetables - notably tomatoes, and an array of ornamentals.

In case you were wondering, wine made with BMSB infested grapes tastes like, you guessed it, BMSBs. Ewwwww. Cattle have been known to refuse silage containing large quantities of stink bugs. Chickens, repeatedly fed buckets of handpicked stink bugs by diligent organic gardeners, are reported to eventually just say ewwwww.

Back to: How do we get rid of them? Sad to say, like Gypsy Moths and Japanese Beetles, it is likely they will never be totally eradicated from North America. So the question becomes questions: "How do we cope?" "How do we minimize crop damage?" "How do we deal with home infestations?"

To answer these questions, we need more information specific to the US. Much existing information comes from studies of BMSB in their Asian native habitat where disease and predators have evolved together, establishing a balance within their ecosystem, as our hardly noticed native stink bugs are balanced in our own.

An official BMSB Working Group, consisting of thirty five scientists, growers, and educators from around the country from leading universities and agricultural agencies, has been formed under the leadership of Tracy Leskey, Research Entomologist at the USDA Appalachian Fruit Research Station in Kearneysville, WV. They have begun to share knowledge and coordinate research efforts. It is nice to know this group is laboring daily, seeking answers to our questions.

Back to: what to do? Dr. Leskeyís advice for homeowners now, in late winter, while most are hibernating, is to wait. Yes, wait. Do nothing until they have swarmed back outside. To caulk now would be to trap them inside your house and spray chemicals risks contaminating your house and your family. Spraying also risks some not receiving lethal doses, as most are in hard to reach places. If they donít receive a lethal dose, they may acquire and pass along to their young resistance which is already suspected of happening with Pyrethroids. So do nothing now. Once they have gone outside to eat & lay eggs, that is the time to resume caulking & shoring up your defenses for next fallís inevitable battle.

If you want to actively do something, now is the time to arm yourself with knowledge so in warm weather you may go on the offensive, destroying them when they are most vulnerable, as eggs and nymphal instars.

There is much more information about BMSBs. The Frederick County Master Gardeners invite you to attend one of our classes on BMSBs to be held at the Public Safety Training Facility, 5370 Public Safety Place (formerly 8349 Reichs Ford Rd), Frederick, MD. Classes are scheduled for Saturday, March 19, 2011, 9-10:30 a.m. and/or 10:30- 12 Noon. Wednesday, March 30, 7-8:30 p.m. Monday, April 4, 7-8:30 p.m.

Space is limited and will be filled on a first to register basis. $5 fee payable at the door will be charged to cover costs of color handouts. Please register at any time by sending a message with your name and phone number by e-mail to If e-mail is not an option, you may register by phone, however, please call only on Mon, Wed or Fridays, 8:30 a.m. -4 p.m. when a receptionist will be on duty, MD Extension Frederick County Office 301-600-1595. Please use this number, not the one below.

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