The Pentatomidae are coming!

This Asian import is not a threat to humans, but the brown marmorated stinkbug can damage crops.

No security fences or border patrols keep out these illegal aliens. They come from Asia, but no one seems to know exactly how they traversed the globe and entered the United States. They were first spotted in Pennsylvania about 10 years ago.

Like Yankee troops 150 years ago, they then apparently moved into Maryland, crossed the Potomac and invaded Virginia. But there is no modern-day equivalent of Stonewall Jackson to keep the offensive hordes away. Instead, the best we can do is learn as much as we can and try to understand them:

Their scientific family name is Pentatomidae — from the Greek “pente” meaning five and “tomos” meaning section — because their antennae are five-segmented. Their bodies are usually shield-shaped, and the wing covers are known as shields.

They often eject an unpleasant-smelling substance when disturbed or killed. This form of anti-predator defense is known as autohaemorrhaging. The liquid ejected contains cyanide compounds with a decidedly rancid scent. Some human noses detect a whiff of spoiled almonds; others, sweaty socks.

Yes, it’s the invasion of the body odors. The insects that emit the smells are naturally known as stinkbugs. Some people call them shield bugs because of their shape.

But the official name is brown marmorated stinkbug. “Marmorated” refers to the bugs’ marbled or streaked appearance. These are not to be confused with green stinkbugs, which are kept in check by natural predators in the United States.

In Asia, a parasitic wasp attacks the eggs of the brown marmorated stinkbug — preventing hordes of the insects from invading homes and agricultural enterprises as is happening in Rappahannock and elsewhere.

The reason they invade area homes is to look for warm places to hunker down for the winter, according to Tim Ohlwiler, Virginia Cooperative Extension horticulture agent. But more than simply a smelly nuisance, they are also very real agricultural pests because their large populations can cause severe damage to crop production, particularly in orchards.

While the pests have a voracious appetite for fruit and other plants — piercing and sucking plant fluids — they don’t harm humans. During the winter, they lie dormant, neither eating or breeding.

“They just come in, hang out, and leave in the spring,” Ohlwiler said.

But how to keep them from hanging out at your place? “The first line of defense is to make sure every crack and crevice in your house is sealed. Update your weather-striping,” says Jason Caldwell, who runs the Piedmont-area business called Pest Wrangler, based in Haymarket.

Stinkbugs are attracted to light, so close the curtains at night and have as few outdoor lights on as possible, advises the Pest Wrangler.

Among natural control methods, Caldwell suggests kaolin, a silicate clay mineral compound usually available through your local cosmetic store: “Try scattering some kaolin clay around your buildings . . . . Studies have shown that stinkbugs are unable to feed on plants covered in this natural clay and thus aren’t able to lay their eggs on the plant surface.”

But if they get inside your house, it’s every man for himself, as every Rappahannock resident interviewed for this story seems to have a different tactic.

Don’t squash them because they’ll stink, so scoop them up and flush them down the toilet, according to one Flint Hill resident.
The weapon of choice for a Washington homemaker remains her trusty vacuum cleaner.

A creative Amissville teenager uses Scotch tape to trap the bugs.

More creative still is what some Asians do: Known as bọ xít in Vietnamese, the stinkbug is featured in that country’s most delectable cuisine.