STEVE INSKEEP, Host:
Now we have the latest coverage on a plague of stink bugs. Stink bugs look like brown shields with legs. They are native to Asia but showed up in the United States, in the mid-Atlantic region, in the 1990s. And they have now spread to 30 states. But as Sabri Ben-Achour, from member station WAMU, reports, help may be on the way.
SABRI BEN: By now, it almost seems like everyone in the mid-Atlantic knows these invaders.
M: They're everywhere in the house.
M: In the couch, in clothing.
BEN: The brown marmorated stink bug.
M: During the daytime, when they swarm, they all come. You know, it was all black on my walls.
BEN: If you try to crush a stink bug, it gives off a smell like cilantro and burning rubber - pretty annoying in your home. But for farmers like Bob Black, it's about money.
M: This thing is really going to put a big chapter in my book of life. I've never had anything affect me like this.
BEN: Black is out checking his stink bug traps at his orchard in Thurmont, Maryland. Like a lot of mid-Atlantic farmers, he's seen some of his crops decimated by marmorated stink bugs. They take their long, needle-like mouthpiece and stick it into the flesh of fruits and vegetables, leaving them bruised and disfigured.
M: One of my late varieties - Pink Lady, which a lot of people like - we had up to 50 percent damage on that. I can handle a few percent. But you know, it gets up to 25 to 50 percent - that's pretty devastating for me.
BEN: And this year will probably be worse. Mike Raup is an entomologist at the University of Maryland.
D: We're going to hear a collective wail up and down the East Coast as hordes of these things come out of people's attics and try to find their way back outdoors.
BEN: He says the problem is pretty basic.
D: When they escaped Asia, they simply arrived here without their natural enemies.
BEN: And taking me down a series of dark, glowing red corridors.
(SOUNDBITE OF ZIPPING)
M: You see that all the light is red to minimize insect flight movement - because most insects can't see red. This looks like a dark room to them.
BEN: Hoelmer takes out try after tray of vials and petri dishes. Inside, rafts of tiny, pearly green orbs sit on leaves. They're stink bug eggs.
M: This is a typical example of a fresh brown marmorated stink bug egg mass. And we're exposing them to female Trissolcus wasps.
BEN: Is that what's crawling around in there right now?
M: That's what's crawling around in the vial right now.
BEN: Parasitoid Trissolcus wasps, from China, Japan and Korea. Just two millimeters long, they don't look like much more than gnats. They don't bite or sting. But Hoelmer tells me that in Asia, they are the mortal nemesis of the brown marmorated stink bug.
M: These small wasps will deposit their eggs inside the stink bug eggs. And then the parasite egg hatches, and its immature stage feeds on the inside of the stink bug egg.
BEN: In a few weeks, out pops a new wasp and no stink bug. Hoelmer says these wasps are extremely specialized.
M: If they can't find stink bugs eggs to lay their own eggs in, they'll die. They can't survive on anything else.
BEN: But there are almost 300 types of stink bugs in the U.S., and a lot of them are helpful because they eat other pests. So Hoelmer needs to know: Will these wasps ever go after them?
M: If they won't attack any of the close relatives, they will not be as likely to attack any of the more distant ones.
BEN: For NPR News, I'm Sabri Ben-Achour in Washington, D.C.
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