Environmental Outlook: Stink Bugs

MS. DIANE REHM

11:06:56
Thanks for joining us. I'm Diane Rehm. An invasive insect unintentionally brought over from Asia poses a significant risk to the landscape and crops. It's also become a nuisance in American homes.

MS. DIANE REHM

11:07:13
It's commonly called the brown marmorated stink bug and 2013 is expected to be a banner year for this smelly pest. For this month's Environmental Outlook, USDA research entomologist Tracy Leskey and University of Maryland entomology professor and extension specialist, Michael Raupp, join me to talk about the biology, ecology and efforts to control stink bugs.

MS. DIANE REHM

11:07:45
I'm sure many of you have seen them. If not, you can go to our website drshow.org and see for yourself what these creatures look like. In the meantime, give us a call, 800-433-8850. Send us an email to drshow@wamu.org. Follow us on Facebook or send us a tweet. Good morning to both of you.

MS. TRACY LESKEY

11:08:15
Good morning.

MR. MICHAEL RAUPP

11:08:15
Even though it's a smelly day, it's great to be here, Diane.

REHM

11:08:19
And Michael, did you have to bring them with you?

RAUPP

11:08:23
The bugs travel with us all the time, Diane. You should know this. We're bug people.

REHM

11:08:29
I see that. and in our studio, we have a round, clear plastic container, about six inches in diameter and inside, I would guess, there are about 20 of these creatures, both male and female. Are they all the brown marmorated species or are there others, Tracy?

LESKEY

11:08:57
I believe Mike has brought you just the brown marmorated stink bug today.

REHM

11:09:01
Oh, thank you, Michael, that was so good of you.

RAUPP

11:09:04
We're purists today. We're being purists.

LESKEY

11:09:06
Indeed.

REHM

11:09:06
Tell me, Tracy, why 2013 is shaping up to be such a big problem?

LESKEY

11:09:13
Sure. One of the things that we have been doing over the last several years is monitoring the size of the population in the late season using some traps. And this gives us a gauge of the size of the population that is going into overwintering.

REHM

11:09:30
What does overwintering mean?

LESKEY

11:09:32
Overwintering is a phrase that we use or a term that we use to describe their diapause or hibernation. It's essentially insect hibernation. So what we're interested in is how many bugs are going into that overwintering phase because when they exit in the spring, that is the size of the population that our growers need to start dealing with.

LESKEY

11:09:54
And so what we knew in 2012 is that the population was about 60 percent higher than it was the previous year.

REHM

11:10:03
Sixty percent?

LESKEY

11:10:05
Sixty percent. So what we saw and what we have observed over the last four years, essentially, are some fairly large fluctuations in the size of that population from season to season.

REHM

11:10:16
Are they getting bigger as we go?

LESKEY

11:10:22
The bugs themselves?

REHM

11:10:23
Yeah.

LESKEY

11:10:24
Um, probably not, but the size of the population definitely fluctuates.

REHM

11:10:27
Okay, all right. Now, Michael, why are we seeing this growth in population?

RAUPP

11:10:36
Well, one of the big things, Diane, is these guys started out only in Allentown, Pa. We believe it was perhaps just a single handful of females or maybe a single female. But what's happened in the intervening, almost two decades now, is these guys have spread like a giant tsunami from Central Pennsylvania.

RAUPP

11:10:58
They're now found, I believe, in 39 states.

LESKEY

11:11:02
Forty.

RAUPP

11:11:03
Oh my, we picked up another one this week.

LESKEY

11:11:05
We picked up another one.

RAUPP

11:11:06
A couple of provinces in Canada. So part of this great tide of stink bugs is simply the distribution has expanded tremendously. They're now colonizing lots of different neighborhoods and crop systems that they never did before. So we're just seeing a lot more stink bugs.

REHM

11:11:23
You know they're on the ground. They're getting at crops. They're getting at fruit. They're getting at vegetables. But they're also flying.

LESKEY

11:11:37
Yeah, and one of the things that we have learned with our colleagues at Oregon State, Nik Wiman, as well as my post-doc Doo-Hyung Lee, they have been using these devices known as flight mills where basically you tether the bug to -- it's kind of like a treadmill, but essentially the bugs fly and these bugs can fly anywhere from one to two miles per day.

LESKEY

11:11:57
And in some cases, some of them fly as much as 20 miles so it's probably not difficult for them to reach your 14th floor abode.

REHM

11:12:07
So how many different species are there? I talked about the brown marmorated, but are there others?

RAUPP

11:12:15
Oh, golly yes. There are literally thousands or tens of thousands of stink bugs worldwide. This is a very large and a very successful group of insects that includes some pretty bad performers, frankly, like this brown stink bug and the green stink bug, which is a crop pest.

RAUPP

11:12:33
But also, surprisingly, some highly beneficial stink bugs. There's one called the spined soldier bug which turns out to be a predator on many kinds of our pests so they're not all good. They're not all bad, but this one is a very, very nasty performer.

REHM

11:12:49
We got them, we think, from a trip from Asia?

LESKEY

11:12:55
Correct, yeah. So these bugs are very good hitchhikers and they probably came in with a shipment of cargo and they have a behavior known as thigmotaxis or thigmotosis where they kind of like to be in contact with layers of stuff.

LESKEY

11:13:10
So they hunker down and hide between, say, layers of cardboard, something like that so they're highly concealed and probably just, you know, came in on a shipment of cargo and, as Mike said, you know, just a handful probably started the invasion back in Allentown.

REHM

11:13:26
Describe that stink bug.

RAUPP

11:13:28
Well, these are prehistoric-looking. I'm looking at these guys right now. They look like a shield. They look like a...

REHM

11:13:33
Yeah.

RAUPP

11:13:33
…Roman centurion shield with six legs. Now, the way we can tell the brown marmorated stink bug from some of our native stink bugs, many of which are also brown, they've got a characteristic pattern of white bands on their antennae. That's the real key.

RAUPP

11:13:52
They also have some banding on their legs. Other stink bugs have this to a certain degree. And the name marmorated, Diane, is very curious. When I first saw the word marmorated, I said, what in the world does that mean?

RAUPP

11:14:04
I think the root is from the Latin, marmorial, which means marbled and if we look along the margin of their abdomen right by those wings, it actually has the patterning of marble, hence the name, brown marmorated stink bugs. But we look for those white bands on the antennae, white bands on the legs and this marbled pattern along their abdomen.

REHM

11:14:25
Okay. So let me be clear, stink bugs have been in this country for a long time?

LESKEY

11:14:34
Oh absolutely, we have about 200 species of native stink bugs here in the United States.

REHM

11:14:39
Okay. But the brown marmorated stink bug is the one we think came from Asia and which is now populating beyond belief?

LESKEY

11:14:51
Right, yes. So this bug as we were talking about earlier, it has been officially detected in 40 states and certainly right here in the Mid-Atlantic are the areas that have been highly colonized, that homeowners and growers of many fruits and vegetables have experienced significant problems. But it continues to spread.

REHM

11:15:10
You know, I have a dear friend who lives out in the suburbs of Virginia. Last year, he told me he was literally sweeping stink bugs out of the house. They really do congregate in great numbers, don't they?

RAUPP

11:15:31
They like to hide out together. They're very gregarious. They like a crowd and they all come to people's homes or their native overwintering sites which are in the forests in fantastic numbers.

RAUPP

11:15:43
One of our good colleagues, Doug Inkley, lives up near Harper's Ferry, Md. and this gentleman has actually collected more than 24,000 stink bugs from his home in a six-month period.

REHM

11:15:56
What are they looking for indoors?

LESKEY

11:15:57
Ah, well, you know, they're looking for a cool, tight, dry, protected location just to spend the winter. You know, they're in overwintering mode. They're basically hibernating. So, you know, Doug Inkley, who Mike mentioned, was finding thousands of these in his attic and that's typically the types of places where we do see large numbers of these stink bugs.

REHM

11:16:19
And if you'd like to see large numbers of stink bugs, you can go to our website. You will certainly see stink bugs, but we've also got some links to a film that Mike Raupp did, also a talk that Tracy Leskey did, drshow.org And you can see people sweeping hundreds, thousands of these creatures. Now tell us why they stink.

LESKEY

11:16:59
Well, yeah, they stink because, you know, they do not want to be eaten so it's better to release a stinky compound, a defensive compound and hopefully, you know, someone will spit you out.

REHM

11:17:10
Another kind of creature?

LESKEY

11:17:15
Yeah, another kind of creature, a predator, maybe a toad, maybe a bird, maybe, you know, somebody's pet even. You know, we certainly know pets like to play with them.

REHM

11:17:26
Who are the predators?

RAUPP

11:17:26
Well, out in nature, I think Tracy hit the nail on the head. There are many reptiles and amphibians that love to eat these things. There are several different kinds of birds that like to eat these things.

RAUPP

11:17:39
One of the curious things, Diane, I don't know if you noticed, but those stink bugs have the distinct odor to many people of cilantro. And one of the fascinating things is one of the compounds in that defensive secretion is the same compound we find in cilantro. It's an aldehyde. It's highly reactive and I did attempt to eat one of those bugs just to test...

REHM

11:17:59
What?

RAUPP

11:17:59
...this out. Yes, indeed. It was the worst bug I ever tasted. I could keep it in my mouth for only four seconds. I spat it out. My tongue was numb for half an hour afterwards...

REHM

11:18:11
Wow.

RAUPP

11:18:11
...so please avoid the urge to eat those things.

LESKEY

11:18:15
A valuable lesson.

REHM

11:18:16
A valuable lesson.

RAUPP

11:18:18
It's no wonder nothing likes to eat these very much.

REHM

11:18:20
I mean, people do eat grasshoppers. People do eat some insects, which have good protein, which can keep people alive. Do not, repeat, do not eat stink bugs. Short break here. And when we come back, we're going to talk about what you should do with these creatures, not what I do, but what you should do if you find them in your house.

REHM

11:20:05
And welcome back. For the time being this is stink bug center. We've got a whole group of them here in the studio in a clear plastic container. And one of our guests, Michael Raupp, who is an entomology professor and extension specialist at the University of Maryland at College Park, was actually talking about having eaten one, which he said numbed his tongue but both tastes and smells like...

RAUPP

11:20:46
...cilantro to several people. Go figure.

REHM

11:20:48
To several people. So you had some colleagues doing the same thing?

RAUPP

11:20:53
Well, no, no. No one was foolish enough to attempt this except me. I take full credit and blame for all of this, Diane. Now, who else in the world would try this? But I couldn't resist.

REHM

11:21:01
It's a good question.

RAUPP

11:21:03
I know.

REHM

11:21:04
Now, Tracey, have you ever put one in your mouth?

LESKEY

11:21:08
Not intentionally but, you know, certainly when they're flying around, you know, buildings in the fall it's a good idea to keep your mouth closed.

REHM

11:21:16
Interesting. Here is a question from Peter who says, "It seems we're hearing about new invasive plant animal bug nearly every week and many are labeled destructive. Do we have any plants animal bugs that can hold their own against invaders? Do any of our plants animal bugs ever get transported over there and become destructive?"

LESKEY

11:21:53
Absolutely. You know, one of the things that happens with just global travel, global trade is that we can easily transport insects, plants, other creatures around the globe. And we try to minimize that as much as possible. But certainly we've had instances where we've -- somehow, you know, there have been creatures transported to Asia.

REHM

11:22:15
Such as.

LESKEY

11:22:15
So one that's very common now is the fall webworm, a very common caterpillar that we see late in the season here that defoliates trees. This is now becoming a big issue in China. So it can go both ways.

REHM

11:22:29
It can go both ways. Here is another, "Chemical burn warning. If one swats one on the skin, a chemical burn results that can last up to a week." Michael.

RAUPP

11:22:45
We've heard this. We've heard cases, particularly with farm workers where they've been working in the orchards and perhaps one of these little stink bugs falls down the back of their collar on a warm day and it gets inadvertently crushed on the skin. These compounds are highly reactive, so I wouldn't be at all surprised if you could -- if this would result in a chemical burn. So I think that could absolutely happen.

REHM

11:23:11
Do you think that that's a particular allergic reaction or do you think it could happen to anyone?

RAUPP

11:23:21
Yeah, I think these compounds are highly reactive. That's just the nature of these defensive -- I think anyone could get a chemical burn from this. The allergy usually is the result of the introduction of a foreign protein, so that's a little different I think.

REHM

11:23:35
Okay. So they stink. They stink if you crush them. They stink if you step on them. What I do and what your film told me not to do, I pick them up with a tiny touch of tissue paper without crushing them and I flush them down the toilet. And you're telling me that's the wrong thing to do.

RAUPP

11:24:09
Diane, it's a delightful thing to do to watch these guys spin their way into oblivion. And there is an element of retribution that is very therapeutic, there's no question. But frankly it just wastes a lot of water. So what I would recommend people do is maybe have a little glass with soapy water in it, simply put them -- and it doesn't have to be in sight.

RAUPP

11:24:32
You can put this in a corner somewhere, simply put them in a bucket of soapy water. They'll drown. And then what I like to do is after they've been treated with extreme prejudice in this regard and are well gone, I simply return them to my compost pile, kind of ashes to ashes. And I simply recycle them to the earth so they can help my plants grow.

REHM

11:24:53
But how about those of us who no longer have gardens, Michael?

RAUPP

11:24:57
Oh my. This is a dilemma.

REHM

11:25:00
Right.

RAUPP

11:25:00
I think this presents a problem.

REHM

11:25:03
I may have to go back to the toilet.

RAUPP

11:25:05
You may -- well, you may have to strain them out, I would say. Do you have some houseplants or some...

REHM

11:25:12
Yeah.

RAUPP

11:25:12
Well, you could surely add them to your houseplants when they've been effectively annihilated. The other possibility, Diane, as I show in my little video, is you can simply collect them in a very simple trap or in a cup. I seal them in a Ziploc bag, I toss them in the freezer for a week. And after they're well frozen, they will be finished and then you can simply...

REHM

11:25:35
Oh, I'm going to look at these things in my freezer for a week.

RAUPP

11:25:38
Well, I guess that would be a problem, wouldn't it?

REHM

11:25:40
Yes, it really would.

RAUPP

11:25:41
Oh, for me it's not a problem, you see.

REHM

11:25:43
Tracey, what do you do?

LESKEY

11:25:44
Well, yeah, I would say maybe an opaque bag. At least you wouldn't have to look at them. That's one possibility. In my house, you know, I have a lot in my attic.

REHM

11:25:54
You do.

LESKEY

11:25:54
I do. I have thousands, so I have a devoted dust buster that is my best friend. You know, we can use that to suck them up. And then I do what Mike says. I put them in the freezer.

REHM

11:26:05
You do.

LESKEY

11:26:06
I do. And then I actually take them to my compost, yes. But, you know, I have a garden.

REHM

11:26:10
Okay. We're going to open the phones because clearly there are lots of people who want to know about stink bugs. Let's go first to Doug, who's at Harper's Ferry and I think you know Doug. Hi.

DOUG

11:26:29
Good morning, Diane.

REHM

11:26:31
Good morning.

DOUG

11:26:31
Hello Tracey and Mike.

LESKEY

11:26:33
Hi Doug.

RAUPP

11:26:33
Hey Doug.

DOUG

11:26:35
Yeah, these guys have helped me out because I called them when I had these 24,000 stink bugs in my house and they killed my asparagus and destroyed my tomato crop. And I even ate one in my chili, so I've joined Mike's club.

RAUPP

11:26:49
Oh baby, oh baby.

DOUG

11:26:51
But, you know, it is a serious problem and it's driven me nuts. I've glad they're not dangerous. But, you know, I don't want this to happen again to me with some other insect. So Tracey mentioned it gets here in global trade. Mike, I really want to know, what can we do to heighten our awareness at the borders to keep this from happening again? This has not been fun.

RAUPP

11:27:13
Well, Doug, I really think this is an amazingly serious issue. Unfortunately we constantly find ourselves playing catch up with these exotic invaders. That really is the crux of the matter. And I think you hit the nail on the head, Doug. I think the way to stop this is simply to prevent these things from entering the country in the first place, rather than spending billions and trillions of dollars trying to undo the mess they make. And I'm going to kick it back to Tracey and see if she has some other thoughts on this.

LESKEY

11:27:48
Yeah, there are some things that everyone can do because, you know, we -- many of us are travelers. We come through airports perhaps from another country. And so if you're bringing agricultural products or things like that, declare them.

REHM

11:28:00
I thought you weren't supposed to?

LESKEY

11:28:01
Well, you know, it is possible but they have to be declared and cleared. And so, you know, following the protocols that are put out by U.S. border and protection and that kind of thing, you know, each of us can help with that. And there is actually a list of tips on I think it's HungryPests.com that will help if you're interested in trying to prevent spread.

REHM

11:28:21
I understand an invasion of another species was recently stopped at seaport in Baltimore. U.S. customs border protection officers found an Italian breed of stink bugs. I wonder if that one tastes like garlic, Mike.

REHM

11:28:43
At the Baltimore seaport in a shipment of tiles. So an emergency action notification was issued to the importer requiring the shipment be sent back or fumigated. The importer chose to have them fumigated. So that didn't even come in on produce, Tracey.

LESKEY

11:29:09
Exactly. That's another pathway, these products that we're importing. And so this is exactly what should've happened. The bug was detected at the port and it was annihilated there. It didn't make it past that point.

REHM

11:29:20
I see.

LESKEY

11:29:21
So that's how it should work.

REHM

11:29:22
Okay. And Doug, before you go I want to know how you managed to get rid of the thousands of stink bugs you confronted.

DOUG

11:29:34
Well, with difficulty because they keep coming out slowly all the time. And believe it or not, I purchased more vacuum cleaners, so now I have one on each floor of the house. And they're dedicated, as long as you can stand the smell of them coming out of the vacuum cleaner. But, you know, you have to do something so that's what I've done.

REHM

11:29:53
So are they all ending up in your compost pile?

DOUG

11:29:57
Yes, they are but I make sure they're good and dead before I put them there, because I don't want them back in my house nor in my garden, which I've pretty much given up on.

REHM

11:30:07
But how do you kill them once you have vacuumed them?

DOUG

11:30:12
They stay in the bag and they die there over time. Sometimes I -- instead of composting them I've actually burned them. Because I just need to get rid of them in any way that I can. And to tell you the truth, I put some of them in my freezer and I send them to Mike Raupp.

RAUPP

11:30:31
Yes, you do, Doug, and thank you very much for that. And the other thing I'd like to add to this. Doug has done a fantastic job of excluding these things from the home. We can't overemphasize the important of using caulking, screening on your windows, screening on your gable end vents. Because if you can keep them out of the house, you're going to eliminate the problem. And, Diane, the other thing, if it's good for keeping out stink bug, it's also good for energy conservation. So you're getting a double bonus by these kinds of exclusion methods I think.

REHM

11:31:05
Do they do any damage within the house besides replicating?

LESKEY

11:31:12
Well, actually they don't even reproduce. They just come into your house and they're basically nonpaying tenants all winter long. But, you know, in large numbers they can stain surfaces because they do excrete some feces over that time. And, you know, bug excrement so nobody really wants that.

REHM

11:31:30
Doug, good luck. Thanks for calling. Let's go to Charlotte, N.C. Good morning, Preston.

PRESTON

11:31:40
Yes. Hi, Diane. How are you?

REHM

11:31:41
I'm good, thanks.

PRESTON

11:31:43
Good. I'm a big fan of the show. This is the first time I've ever called in so thanks for taking my call.

REHM

11:31:45
I'm glad to have you with us.

PRESTON

11:31:48
Yeah, absolutely. My question was, so I'm actually from Texas and New Mexico and grew up in the mountains of New Mexico. And when I was younger my brother and I would be out on our land and there were these large black beetles that we always called stink bugs. And everybody around there called stink bugs. And they would spray this kind of acrid smelling, really, really irritating brownish red fluid. And when I finally moved out here I saw one of what you're referring to as stink bugs. And my wife called it a stink bug I Said, no that's not a stink bug. Those are those big black beetles that spray the red stuff. And she looked at me like I was crazy.

PRESTON

11:32:24
So I just kind of wanted from entomology standpoint just to hear what your guests' thoughts were on the delineation there between the different species and kind of how obviously there's -- just knowing the types of beetles. And I think Darwin said, God had an affinity for beetles because there's so many of them.

REHM

11:32:42
That's great. All right. Before you respond, Mike, let me just remind you, you're listening to "The Diane Rehm Show."

RAUPP

11:32:53
It's an excellent quote, Preston. I think actually it was Haldane, another famous biologist. But he was absolutely right. There are more species of beetles than any other kind of insect, or for that matter, metazoan higher life form on the planet. Now to get back to your point, there are a number of ground dwelling beetles, Tenebrionids, and some of the carabid beetles that live on the ground that are fully equipped with highly noxious chemicals.

RAUPP

11:33:22
In some cases -- again, these are defensive secretions. This is all part of the game for many different types of insects -- some of these beetles are called bombardier beetles. And they actually have a reaction chamber where they mix two chemicals. It has an explosion. So not only is it noxious but it comes out at a very high and scalding temperature. So next time you're in the desert camping, Preston, don't look too closely at those things or you might get a very nasty surprise. But the beetles are kin -- distant kin to our stink bug friends. But many of these things are chemically defended.

REHM

11:34:00
I see. Thanks for calling, Preston, What do they eat?

LESKEY

11:34:05
Well, this stink bug is not a fussy eater. This stink bug will feed on over 100 different plant species. So everything from tree fruit like peaches, apples, nectarines to veggies like tomatoes, eggplant, ochre, sweet corn. They feed on our row crops, soybeans, field corn, grapes, small fruit.

REHM

11:34:28
How much damage can they do?

LESKEY

11:34:30
They can wipe out a crop.

REHM

11:34:32
Really.

LESKEY

11:34:33
We've had growers, especially in 2010 when we had the very large outbreak year, that lost their entire crops.

REHM

11:34:40
Ah.

LESKEY

11:34:41
Yeah, yeah.

REHM

11:34:42
And is insecticide of any kind of use?

LESKEY

11:34:48
It is, you know. And one of the things that we have learned over the last few years are those insecticides that are effective at killing the stink bug. But certainly with each insecticide that a grower is required to use, each application, that adds cost. And there are also consequences to that use. It disrupts, you know, some of the integrated pest management tactics, which are sort of sustainable tactics that our growers use to kind of get the most out of the environment. So, you know, there are consequences to this, both financially and ecologically.

REHM

11:35:22
And here's a caller who is an organic gardener. Maggie, you're on the air.

MAGGIE

11:35:31
Thank you. I have a very small home garden and I do a lot of mechanical removal of pests. We have quite a few of our own stink bug family down here in Texas and each has its own scent, so you already answered my question about the smell. But what organic methods are there? Sticky traps? Is there some kind of bait that they will go to, orange oils, spinosad? Do you know of any of those that work on them?

RAUPP

11:36:02
Yeah, Maggie, you know, we're in the process, the final stages of evaluating some of these, what we call RTUs or ready-to-use compounds against these particular stink bugs. And we were very pleasantly surprised that a couple of the compounds, including some that you mentioned, the spinosad compounds, actually if you treat the young nymphs -- now remember the nymphs are the immature stages. So with a stink bug we have eggs. Those eggs hatch into what we call nymphs. Those nymphs will molt five times or have five nymphal stages before they molt to the adult stage.

RAUPP

11:36:43
And we find that if you can treat them with something like spinosad, which is one of the compounds that is very environmentally safe, or even things like insecticidal soaps and insecticidal oils can be highly effective in killing those young nymphs. And that's really the stage you'd like to control. The big guys quite frankly are pretty darn tough to control so...

REHM

11:37:11
Really.

RAUPP

11:37:12
Oh, I think so, yes. We don't have all that much luck with the big guys in a vegetable garden setting.

REHM

11:37:18
How about in a flower garden setting?

RAUPP

11:37:21
Similar, similar. But I think they've found some materials that work pretty well for our orchards.

REHM

11:37:27
All right. We'll talk about orchards when we come back and take more of your questions, comments on stink bugs.

REHM

11:40:02
And welcome back. We are talking in this hour about stink bugs, not only are they here in the studio, but also, Tracy Leskey. She's a research entomologist with USDA, project director of the Stop The Brown Marmorated Stink Bug Project. And we've got to talk about that project. Mike Raupp is an entomology professor and extension specialist at the University of Maryland, College Park. Let's talk about bio control, what you mean by that and how it can be accomplished with these creatures.

LESKEY

11:40:55
Well, one of the things we know, Diane, is that this bug is not just in one particular crop or one particular location. It's distributed across the landscape. It feeds on many different species of plants, including important crops, as well as wild host plants, like some of our deciduous hardwood trees. So what we're thinking about with biological control, which is essentially using predators, pathogens or parasites to attack this insect and help keep it in check, something that we can distribute and rely on across the landscape to help reduce these populations.

LESKEY

11:41:28
So it can be things like predacious beetles, uh, parasitic wasps and, you know, those individuals can attack and help keep these populations in check.

REHM

11:41:41
You know, I'm thinking back to the discovery of the first snakefish that showed up in this area. And now the lakes, the rivers are crawling with them. What is it in the environment that allows these creatures to multiply in such a way that virtually nothing can stop them, Mike?

RAUPP

11:42:16
Well, when they get here they enter what we call enemy-free space. So back in Asia where these things evolved there's an entire complex, an entire food web of organisms that feed on these stink bugs. And when they arrive in this country, hey, it's like welcome to America. You know, they've traveled on an airline and the baggage is lost. So when they get here, there simply are not the same kinds of organism or the rich diversity that helped their lower populations.

RAUPP

11:42:48
The good news here, Diane, as Tracy has alluded to, is right now there's an effort underway in USDA to discover the insects that attack, particularly the ones -- tiny wasps that attack the eggs of these stink bugs, vet them, bring them through quarantine and release them. The other interesting thing, the fascinating thing we're finding now is there's also significant pushback on these stink bugs by the indigenous natural enemies that are already here. So we're seeing some of our own tiny wasps begin to attack these things.

RAUPP

11:43:28
We're seeing in a very odd twist of fate, the Chinese praying mantis, which was introduced to this country accidentally in the late 1890's, actually loves to eat these stink bugs, which it evolved with. I think it's simply the reunion between two old friends.

REHM

11:43:47
But how long is that gonna take, Mike?

RAUPP

11:43:49
Well, you know these kinds of things do take awhile to adjust. The good news is it's happening. The other good news here, maybe Tracy can speak to this if we have time, is this other effort is fully underway and we hope in a couple years that we might be able to release some of these parasites.

LESKEY

11:44:06
Yeah, this is referred to as classical biological control, where we bring another one of its old friends back from Asia. So these are parasitic wasps, native to Asia, that attack the eggs of brown marmorated stink bug in that part of the world. And our colleague Kim Holmer has spent a lot of time traveling through China, Japan and Korea collecting these wasps, bringing them back. They're in quarantine, as Mike mentioned, and undergoing a screening process. And that screening process is pretty rigorous because what we have to do is ensure that it is not going to attack our native stink bug species.

LESKEY

11:44:40
And so it's going through a series of trials. It's in quarantine in Newark, Del., as well as colleagues in Oregon, Florida, Michigan and Mississippi are joining in.

REHM

11:44:50
Tell me why you want to protect the native species of stink bugs.

LESKEY

11:44:56
Well, as Mike mentioned, you know, these stink bugs are part of a greater food web. They are food for birds, for example. And so there may be a particular species of bird that specializes on a particular species of native stink bugs. So we don't want to disrupt that cycle.

REHM

11:45:12
But are you saying that a bird would turn up its nose at this…

LESKEY

11:45:17
Some birds don't, but some birds we hear do. So, you know, some birds are developing a real taste for brown marmorated stink bugs, but we hear from other people, for example, that their chickens will or will not eat them. So it's an open question, I think. There's good work being done to try to understand that, but as Mike said, you know, these are a relatively new addition to the ecosystem so the birds have to recognize it's a good food source.

REHM

11:45:44
And what is the -- if you can tell me -- the likelihood of danger that these wasps that are in quarantine might not themselves become some kind of over abundant, dangerous species?

LESKEY

11:46:04
Sure. So first of all, they're a non-stinging wasp species. They're about the size of a comma on a printed piece of paper. They're tiny. They're very tiny. And they attack stink bug eggs. That's all they eat. And so if they don't have stink bug eggs they starve and die. However, so, you know, this is this process of what we call host specificity screening. If they are not specific enough, you know, they may not be granted a permit for release. That's the whole idea, to ensure that something like that doesn't happen. That is why the process is in place.

REHM

11:46:34
And do they also sting human beings?

LESKEY

11:46:38
No, no, no. Just eggs.

REHM

11:46:39
Okay. Here we go to Cape Coral, Fla. Good morning, Jim.

JIM

11:46:46
Hey, Diane. My question is, I'm from Wisconsin and I've never seen a stink bug. I've lived in Florida 30 years and I just wondered, are they in Florida? Do you know? Because I've never seen one down here in southwest Florida, but I went to Wisconsin and my cousin's house was covered in them.

REHM

11:47:04
Oh, my.

JIM

11:47:07
So do they freeze out in the -- I've got -- I could ask a million questions. I just want to get one. Do they freeze out in the winter and if so, why aren't they dead there?

LESKEY

11:47:17
No. No.

REHM

11:47:18
Okay.

LESKEY

11:47:19
Sorry, Jim, they don't unfortunately do that. We have detected them certainly in Wisconsin, as well as Florida. There are established populations even in Hamilton, Ontario and Zurich, Switzerland. So they can survive some cold winters.

REHM

11:47:32
So it's interesting he's not seeing them in Florida.

RAUPP

11:47:36
We have detections in Florida, but the populations simply haven't established there. Remember, now, Diane, these guys were here for really a number of years before we realized the magnitude. Oftentimes what we find is there's a lag time between the detection of the first stink bug, when they become a nuisance problem in people's homes and then often in about a five-year time frame, that's when we start to see the damage on our agricultural crops.

REHM

11:48:05
Okay. So they started in Pennsylvania. That's where they first were discovered. Did they migrate south? Did they migrate west? What did they do?

LESKEY

11:48:17
So, yeah, so they definitely, quickly, went east into New Jersey.

REHM

11:48:23
East? Okay.

LESKEY

11:48:23
And then we started seeing them in Maryland in 2003, West Virginia 2004, Virginia 2005. And it continues. So it's radiated out from there. And as we were talking about earlier, they can fly fairly long distances, but also they're hitchhikers. So people can take them to new locales, as well.

REHM

11:48:39
All right. To Poplar Grove, Ill. Hi, Andy.

ANDY

11:48:44
Hi, Diane. Thank you so much for taking my call today.

REHM

11:48:48
You're welcome.

ANDY

11:48:50
Well, I am part of a mid-sized orchard, here in Northern Illinois. And although we haven't had a problem with stink bugs yet, my question was is there a specific reason why they're going after the fruit? We have other bad insects that will start to burrow into the apple after they may lay their eggs for example. So is there a particular reason why they're targeting our fruit or are they just hungry?

LESKEY

11:49:17
Well, they are hungry, that's for sure.

REHM

11:49:19
Yeah.

LESKEY

11:49:20
But they typically go for fruiting bodies. That is what they're looking for, whether it's an apple, a peach or a nectarine or some sort of seed pod on, you know, a woody plant. So, yeah, that's what they're looking for.

REHM

11:49:33
Do they ever get fat?

LESKEY

11:49:35
They do. They do actually. At the end of the season, the growing season before they enter overwintering we weigh them, actually, to look at how much they weigh because this gives us an indication of how…

REHM

11:49:45
I bet you love that.

LESKEY

11:49:48
You put them on a scale.

REHM

11:49:49
Yeah.

LESKEY

11:49:50
But we look at their weight loss over the period of the winter months because that's going to give us an indication of survivorship.

REHM

11:49:56
Tracy, what is their lifespan?

LESKEY

11:49:59
Well, in the field -- so, for example, when those first eggs are laid, it takes typically 50 to 60 days for them to complete development from egg to adult. After that, the adults that overwinter are going to spend about six months in that sort of semi-dormant phase and then emerge the next year. So potentially eight or nine months, would you say, Mike?

RAUPP

11:50:23
Um-hum, I think that's about right. That overwintering generation is much longer than the summering generation. There are two generations believed to be in this part of Maryland and West Virginia. And the summer generation, actually, is a little bit shorter because they simply don't have to endure that winter.

REHM

11:50:41
Okay. John, in Chapel Hill, N.C. has a funny story to tell us. Go ahead, John.

JOHN

11:50:50
Hi, Diane. Thanks for taking my call.

REHM

11:50:53
Sure.

JOHN

11:50:54
I was just calling because I have a funny story. Back in February, me and my girlfriend were celebrating our anniversary. We went out to western North Carolina and rented a cabin for the night. It had a lot of character, it was cozy, log cabin. It had a fireplace. And early in the night I noticed a bug walking around and I thought it was kind of gross, but didn't pay much attention to it. And as the night went on I saw more and more of them. So I called the owner to ask if these are dangerous.

JOHN

11:51:28
And she's like, oh, no. They're harmless. They're just stink bugs. And needless to say having the word stink in the name didn't reassure me very much.

RAUPP

11:51:36
Oh, the ambience was lost?

JOHN

11:51:40
Basically. And so I remember we were watching a movie, I look over to the table and there's a stink bug crawling around on my food and I flicked it off and I put it under a glass cup. I look again in three minutes and there's another on it. And I was just amazed at their ability to get into and onto anything that was left out in the room. And so finally we realized there was no containing these things. They were everywhere. They were flying around everywhere. So we just went to sleep under the covers because we were afraid they would crawling all over our faces that night.

RAUPP

11:52:15
Romantic memories made all the more memorable, John.

REHM

11:52:19
I should say.

JOHN

11:52:19
Absolutely.

LESKEY

11:52:19
Indeed.

REHM

11:52:20
But, John, here's what I wanna know, how did your girlfriend feel about your choice of vacation spot?

JOHN

11:52:29
Well, I think it's the thought that counts. So I'm pretty sure that I got a kudo for the trip.

REHM

11:52:33
You're right. You're right. Better luck next time. Thanks for calling. Okay. And to Harpers Ferry, W.V. Good morning, to you, Brian.

BRIAN

11:52:49
Good morning, Diane. Thanks for taking my call.

REHM

11:52:51
Sure.

BRIAN

11:52:52
I love this. I wanted to let you know what we do with our stink bugs up there in Harpers Ferry. My three-and-a-half-year-old son spots them, you know, from 15 feet away. And he runs and gets his BugZooka. You compress the back of the BugZooka, point it towards the stink bug or spider, press the button and a vacuum sucks it into a clear cylinder. He takes a look at them in there and just loves to watch them crawl around. And we get spiders and everything. The spiders seem to get bigger and bigger, but the stink bugs just die.

REHM

11:53:24
Tell me about BugZooka.

LESKEY

11:53:26
Yeah, the BugZooka is pretty effective. You know that vacuum power, when you sort of pull the trigger back, it really sucks up any bug that you might have crawling across your ceiling and that sort of thing. And it holds them in this collection chamber, so you can view them, you know, basically locked up for life after that.

REHM

11:53:41
Where do you buy a BugZooka?

LESKEY

11:53:43
You know, I'm not sure. I think they're available like probably through Amazon, but I'm not sure.

RAUPP

11:53:47
Yeah, I think you can get them online, Diane.

REHM

11:53:50
Is that where you got yours, Brian?

BRIAN

11:53:51
That is, Diane. And no batteries involved. So it's a cheap way to rid of them.

RAUPP

11:53:55
Pretty green.

LESKEY

11:53:56
Yeah.

REHM

11:53:56
Well, that's good.

RAUPP

11:53:57
I'm liking it.

REHM

11:53:58
Glad to hear it, Brian. Thanks for the call. And you're listening to "The Diane Rehm Show." To Cincinnati, Ohio. Good morning, Jed.

JED

11:54:10
Good morning, Diane. A question for you guys, the abrasive nature of the stink bug, has that ever been considered to be used as like an organic pesticide?

RAUPP

11:54:24
I think the defensive secretions you're talking about, Jed, are highly volatile. And, frankly, after that organism dries out a little bit, that odor, unfortunately dissipates. And it's a clever idea, but I don't really think we could, unfortunately, be able to harness that stinky power in a useful way.

REHM

11:54:47
Hope that answers it.

RAUPP

11:54:49
Good idea.

JED

11:54:49
Thank you.

REHM

11:54:50
Thank you. And to Franklin, N.H. Hi, Bill.

BILL

11:54:56
Hi, Diane. Bill Farren (sp?) from Franklin.

REHM

11:54:57
Good to have you with us.

BILL

11:54:59
Well, thank you. The reason I'm calling is because I once had a problem in my garden. I think they were stink bugs. They were black. They were an inch and a quarter long. They smelled horrible. And if you touched them your fingers would get little burn marks on them, rashes, like. And I never had them before until I started using hay and straw for mulch. Now, my question is, is it -- I stopped using hay and straw for mulch because of that. Is it the hay and straw that attracted or did they just happen to show up at the time I first used hay and straw for mulch?

REHM

11:55:36
Michael?

RAUPP

11:55:37
Yeah, I think what you had, Bill, was what we call blister beetles. Blister beetles tend to be very common in the autumn. You will find them in hay fields. In fact, in some cases they can be rather toxic. We've had cases where livestock, horse in particular, have been intoxicated by ingesting these things. As the name implied, they have a very, very nascent defensive secretion, which will cause blisters, fluid-filled blisters. And these are nasty characters so I'm glad you got rid of that straw. And I hope you can keep those blister beetles away from your horses.

REHM

11:56:13
Exactly. And finally, to Traverse City, Mich. Hi, Rick.

RICK

11:56:20
Well, hi, Diane. I love your show. Thank you for having me on.

REHM

11:56:23
Very quickly, sir.

RICK

11:56:25
Yes. I found one way to keep them out of my house. I've lived in this house in northern Michigan, Traverse City for the last three years. And I back to the Pere Marquette National Forest. And I found these stink bugs. I didn't know what they were for awhile and they're getting into my house, season after season. And then all through the winter they're coming out. What I found is, it's not the windows and the door walls they getting into because I had caulked everything and had the house painted. They're coming in the vents, the ceiling vents in the bathrooms.

RICK

11:56:54
And they sit there all winter inside of these vents and then they slowly come out during the winter and then they're flying around the room and now I'm having more trouble identifying where they were coming in, but my neighbor tipped me off. He says, it's the vents. He says we had the same problem and they were still getting in. And we capped our vents with screening and it keeps them out.

REHM

11:57:15
That's a great tip. And on that positive note, we will end. Tracy Leskey, Mike Raupp, thank you both so much. I did not appreciate having those (unintelligible).

RAUPP

11:57:33
Oh, I’m sorry.

REHM

11:57:34
Okay. Thank you all for listening.

LESKEY

11:57:35
Thank you.

RAUPP

11:57:36
Thank you, Diane.

LESKEY

11:57:36
Thanks so much.

REHM

11:57:39
I'm Diane Rehm.
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