Stink bugs moving back indoors for the winter; search continues to stop, trap them

1007 bug trap1 gp.jpgJody Williams of Delaware Township puts together his stink bug trap, made of cardboard and wood.

Stink bugs are back, searching for a winter hideaway after spending the summer eating and continuing the species.

Research in New Jersey and elsewhere is seriously under way for methods to eliminate the Brown Marmorated Stink Bug, which attacks a wide variety of crops before turning to its nuisance phase — overwintering in homes.

Traps, some more effective than others, are proliferating. One that still draws praise is a simple, cardboard-and-wood slat invention first shared by Delaware Township resident Jody Williams two years ago.

So far, it looks like this year's crop of stink bugs could be the smallest in the past four years, said Dr. George Hamilton, head of the Rutgers University department of entomology and an expert on this non-native species.

Newly approved sprays spread by farmers this past summer may have had an effect, said Hamilton, particularly when combined with all of the homeowners who meticulously flush or otherwise trap and destroy the large, prehistoric-looking bugs.

Each female carries, in the wild, 10 egg sacks with 28 eggs each. It's easy to see how the bug, which has no natural predators in the United States, has spread to 36 states.

That's likely happened through one of two routes, said Hamilton -- in moving boxes and aboard freight trucks. The first sighting in California, he explained, was at the home of someone who had moved from Pennsylvania. A college student's boxes are thought to have sheltered them on a trip from Pennsylvania to South Carolina.

In Nebraska, said Hamilton, it was a Roadway freight terminal.

But the heaviest infestations remain in the Mid-Atlantic states, including New Jersey, and a lot of research is under way for ways to keep them from dining on crops and out of homes, where they winter.

Mark Mayer, supervising entomologist at the state Department of Agriculture, said the Brown Marmorated Stink Bug is found in orchards "year-round" and tends to move into field crops from hedgerows.

Mayer listed some of the many foods the bugs enjoy: fruit including peaches, apples, mulberries, citrus; beans, snap and soy; and ornamental plants. Bite into an apple and find a number of rot-like lesions inside, said Mayer, and it may have been stink bugs earlier in the growing season, ruining marketability.

Hamilton adds to the bugs' diet: crab apples, holly berries, redbud, the cones of hemlocks, maple seeds in fall ... "If you cook up corn and notice black kernels," he said, "that's where the stink bug stuck its mouth parts in through the husk and sucked out" the juice inside. "Native stink bugs can't do that."

Mayer and Hamilton are two researchers working with other groups, such as the USDA, on the problem.

Hamilton said that farmers have "more options now than we did two years ago," but it's a double-edged sword. Certain sprays have been approved for use on Brown Marmorated Stink Bugs, he said, leading to "more spraying than in the past 10 to 15 years."

That increases costs and has an environmental impact, including a side-effect of killing natural enemies of some other pests. Then, Hamilton said, "we may have to spray more for that; it's why we didn't use these things in the past."

From the homeowner's viewpoint, Hamilton said that there are more commercial traps in home centers. "It can help, but we can't guarantee it will solve the problem," said Hamilton.

stinkbug.jpgA file photo of a brown marmorated stink bug.

Rutgers has been field-testing a new pheromone. "We're hoping it will have season-wide attractiveness" for "better control," said Hamilton, without being quite "as effective as the Japanese Beetle trap is," because the latter draws insects to properties with the traps.

The good news, he added, is that there is "a lot of commercial interest" in distributing remedies, for both agricultural and home use. He co-chairs the national Brown Marmorated Working Stink Bug Group, which consists of 80 members, including farmers, researchers, industry and government representatives.

Two years ago, Williams was bothered by the bugs and created the cardboard-and-wood trap. Hamilton agrees that it's easy and effective.

Hamilton thinks the non-native stink bugs are "like cockroaches, they like something touching their upper and lower surfaces" when settling in for the winter. Wherever that void is, they won't eat.

In that way, said Hamilton, they're like bears, bulking up with food before moving indoors.

Last year Williams asked nj.com and Hunterdon County Democrat readers with large infestations to contact him so that he could test ideas for traps. He's looking for a few new places again this fall.

He found, he said last week, that one house can be inundated, while the rest of a neighborhood is problem-free. He believes that homes surrounded by woods are most likely to have a problem, but that doesn't mean everyone will.

Hamilton said that researchers are trying to learn what makes one home more attractive to the Brown Marmorated Stink Bugs than another. "Is it your plant material? Is is the color of your house?" he said.

One thing that's been ruled out is housing density — it doesn't seem to matter.

All three say the best advice for homeowners is still the most energy-efficient one as well: seal up around windows and doors and remove or seal window and wall air conditioners very well. Fine mesh screening on attic vents also helps.

Some people pluck them off a wall and toss them outdoors. "Unless it's 20 degrees out," they'll just find their way back inside, said Hamilton.

Basic soapy water will kill them, he said, but bug bombs "are probably not effective" in the long term and are "not a good idea to begin with."

This year Williams is again looking for a limited number of test houses. He's also setting up a playhouse of sorts on his own property, to test some of his theories. "It's some discovery stuff that I need to confirm," he said, but wouldn't reveal details.

Mayer warns homeowners who take a vacuum to the bug — which releases an offensive odor when threatened — to do so with power "behind the bag, not in front of the bag." Otherwise "you get stink bugs in a blender and you've ruined your vacuum."

Related coverage:

Stink bugs present a growing problem in N.J. as population increases

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