Stink bugs: Time for hand-to-hand combat

It is time to smash some bug eggs. This is a citizen-based action, somewhat gooey, recommended by authorities who are battling a Maryland pest, the brown marmorated stink bug. Squashing an adult bug generates an unpleasant odor that gives the bug its name. Not so with the eggs.

Last summer this Asian import feasted on Maryland's fruit crop, munched on vegetables in the central and western parts of the state and in some cases invited itself into homes. Maryland Congressman Roscoe Bartlett labeled it a terrorist bug and called the infestation a plague of Biblical proportions. Over the winter the stink bug took cover in a variety of hideaways, including engines of stowed snow blowers, causing them to overheat when their owners fired them up for the first time.

Now the bug is back. Already 25 percent of some peach orchards and 15 percent of some apple orchards have been damaged by the stink bug, The Frederick News-Post reported this week. Since the stink bug attack sneaked up on Maryland last summer, there is no comparable crop damage data compiled from last spring. But reports from the field say the stink bugs are swarming. Judging by the bug's behavior last year, we are entering the first of two spikes in its population, said Steve Allgeier, Home Horticulture and Master Gardner Coordinator for the University of Maryland Extension in Carroll County. Bug watchers say the two prime times for stink bug activity in Maryland are from late June to mid-July and from mid- to late August.

Now the females are laying eggs, a clutch of 20 to 30 eggs in a cluster, under the leaves of crops that they like to eat. The stink bugs are far from picky eaters, so there a lot leaves to examine. While their first choice is fruit, the stink bugs also chow down on corn, beans, peppers, tomatoes and other garden vegetables. Adult bugs punch a hole in a vegetable or fruit and inject materials which spoil portions of the flesh. This presents no health threat to humans but necessitates carving out damaged chunks.

Mother Nature has not been much help in the stink bug battle. The search is on for an effective stink bug predator. The praying mantis and spiders do like to dine on stink bugs, but they don't eat enough of them to be significant deterrents. A parasitic wasp, which keeps the bugs at bay in Asia, is being studied in a secure laboratory in Delaware. But even if it is determined that it is safe to let the wasp fly here — and that process could take three years — there is no guarantee that some native creatures would not wipe out the wasp. It is a bug eat bug world.

Researchers also are trying to come up with pesticides that will poison stink bugs without killing beneficial insects. In addition they are working on repellants that will deter stink bugs and fungi that will attack them. A USDA lab in Beltsville is trying to identify pheromones — sex lures — that will work with the Asian invaders.

In the meantime, a small, simple stink bug fighting strategy is go out in the garden, turn up the leaves of the plants, and squash the egg clusters, which resemble white to yellow grains of rice. This tactic, which Mr. Allgeier referred to as hand-to-hand combat, can be supplemented by spraying the eggs with insecticidal soap which dissolves the egg casings. Spraying under the leaves, in effect spraying upside down, can be tricky, he said. But eliminating the egg clusters early in reproductive cycle could result in fewer stink bugs in August.

So on when looking for something to do this summer, sidle outside, lift up some leaves, and squash some eggs. It is a messy act that could benefit fruit growers, gardeners and the environment.

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