Stink bugs: Are they bugging you?

September 11, 2010|By ANNETTE IPSAN / Special to The Herald-Mail
  • Native to Asia, the stink bug, seen here as an adult, have become an overwhelming nuisance here in the United States. We want them gone. The biggest problem? They are resistant to most chemicals.
Photo courtesy of Tim Doyle,

The pesky stink bugs that have caused us grief the last several years are back in record numbers and causing more trouble than ever.

They're on our tomatoes, peppers, corn and peaches. They are wiggling their antennae at us from window screens and doorways, contemplating entry into our homes. Mid-September is the time when they start tucking into any crevice they can find to survive winter's cold.

What can we do? Fight back.

The eggs of the brown marmorated stink bug hatch in August and the young - unlike the adults - are vulnerable. You can spray them with pyrethrins, an organic treatment you can find both at better garden centers and online.

Young stink bugs don't look a bit like the adults. Out of clear round eggs pop tiny oval orange and black nymphs. They then morph into miniature versions of the adult stink bugs. Again, when they are small, they are vulnerable. So spray them with pyrethrins. You can also knock stink bugs of any age into a bucket of soapy water.


Because the adult stink bugs start moving into our homes soon, this is the ideal time to batten down your hatches. Grab your silicone caulk gun and seal around doors and windows. Fix or replace screens with holes. Caulk around baseboards, ceiling lights, ceiling fans, utility pipes and behind chimneys. Remove window air conditioners. Keep the stink bugs out and they will die in the cold.

How did these stink bugs get here and why are they around in such big numbers? They are foreign invaders, native to Asia and most likely slipped into the country unintentionally on some packing material. International commerce moves international pests.

These alien stink bugs are here minus any native predators. They smell bad and probably taste bad, so none of our birds or predators want anything to do with them. (Except columnist Tim Rowland's chicken, Stinky.) They multiply unchecked.

Stink bugs spend their summers feeding on plants, using their straw-like mouthparts to suck out juices from soft fruits and vegetables. They leave little hard spots on tomatoes and peppers and can devastate corn and mar peaches. So farmers and orchardists don't like them any more than we do.

Moving indoors in the fall, stink bugs take up residence in any place that's not freezing. Attics, wall voids, garages and sheds are all fair game. They aren't doing any harm in there, just going into a slowed down state of semi-hibernation. They don't breed, make nests, eat anything or cause damage. If persistent warmth hits them, they might revive and show themselves. In the spring stink bugs emerge, annoying us again by swarming while they find the great outdoors.

Instinct tells us to reach for chemicals, but that's a mistake. Adult stink bugs are resistant to most chemicals. Plus, we never recommend spraying insecticides inside your home because of the health risks. Aerosol fogger "bug bombs" barely make a dent in the population. And spraying insecticides into wall voids causes piles of dead bugs that attract carpet beetles and other decomposers that might come after your clothes, carpets and other linens.

Just vacuum up any stink bugs in your home and dispose of the vacuum bag to avoid their namesake odor.

There are treatments you can spray around your home to create a protective perimeter before stink bugs enter your homes. However, they are only mildly effective. These synthetic pyrethroids kill stink bugs, but only last a week or so. Because stink bugs move into homes over six weeks, the treatments do little to control them, even with repeat applications. These potent chemicals must be applied by a certified pesticide applicator at a cost of several hundred dollars.

Unfortunately, there is no magic bullet for controlling stink bugs yet. If you'd like to learn more, visit the University of Maryland Home & Garden Information Center website at and click above the stink bug photo on the home page. Up will pop our fact sheet and links to information from Penn State University, Rutgers and the Northeast IPM Center.

Annette Ipsan is extension educator for horticulture for the University of Maryland Extension -- Washington County.

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