They’re the ultimate stowaways: bugs that hop into cargo ships or suitcases and travel abroad. The latest arrival in our area is a species of moth never seen in the U.S. It turned up in May at the port of Baltimore in a shipment of soybeans from China. In a world of international trade and world travel, we’ll look at the arrival of invasive species of bugs, the damage they cause and efforts to combat them.


  • Michael Raupp "Bug Guy" and Professor of Entomology, University of Maryland
  • Bob Nowierski Entomologist; National Program Leader for Bio-based Pest Management at the USDA’s National Institute of Food and Agriculture


  • 13:06:39

    MR. KOJO NNAMDIFrom WAMU 88.5 at American University in Washington, welcome to "The Kojo Nnamdi Show," connecting your neighborhood with the world. They're clever stowaways hiding out in shipments of grain from Asia, in wooden pallets loaded onto ocean-going cargo ships, even in your suitcase on the way home from a European vacation. Invasive species of bugs have been making their way to the United States for years. And as international trade and world travel increase, the variety of invaders is on the rise.

  • 13:07:18

    MR. KOJO NNAMDIIn May, inspectors at the Port of Baltimore found a moth they'd never seen before in a shipment of soybeans from China. For most Washington residents, the most noticeable foreign invaders are the brown marmorated stink bugs, which seem to hold conventions by the thousands, sometimes inside our homes. But lesser known invaders are also attacking trees and crops across the country. The challenge now, finding creative ways to halt the damage. And joining us in studio is Mike Raupp, the "Bug Guy" and a professor of entomology at the University of Maryland. Mike, good to see you again.

  • 13:07:50

    MR. MICHAEL RAUPPIt's great to be here, Kojo.

  • 13:07:51

    NNAMDIAs usual, you come bearing gifts. But we'll get to that later on.

  • 13:07:55

    RAUPPYeah, you...

  • 13:07:55

    NNAMDIAlso joining us in studio is Bob Nowierski. He's an entomologist and national program leader for Bio-based Pest Management at the USDA's National Institute of Food and Agriculture. Bob Nowierski, thank you for joining us.

  • 13:08:08

    MR. BOB NOWIERSKIYeah, good afternoon. Nice to be here.

  • 13:08:09

    NNAMDIIf you have bug questions or comments, you can bug us. Call us at 800-433-8850. Send email to What invasive bug species do you encounter most often? 800-433-8850. You can send email to Bob, in May, agricultural inspectors at the Port of Baltimore were sifting through a shipment of soybeans from China, when they found a type of moth never before seen in the United States. What's the process for checking food coming into the country?

  • 13:08:43

    NOWIERSKIWell, we have a Customs and Border Protection that sifts through the cargo containers coming into the U.S. They can't inspect them all, so they typically take a subsample of cargo containers, open some up. They may contain grain, they may contain plants or other sorts of organisms. So they take a subsample out of that cargo container to see if they see anything suspicious in there or moving or maybe it's a seed that doesn't look like a wheat grain that needs some attention. Or maybe they see an insect. In the case of the soybeans in Baltimore, they found this little moth in there.

  • 13:09:21

    NOWIERSKISo then they have the option of sending the whole cargo shipment back that contains a crop, in this case soybeans, or they can destroy it. So it's up -- at the discretion of whoever shipped this thing in and is responsible for the goods.

  • 13:09:36

    NNAMDIAnd if it's something that they have never seen before at the port or the airport, how do they detect and be able to define -- distinguish exactly what it is?

  • 13:09:47

    NOWIERSKIWell, typically, the Customs and Border Protection uses some diagnosticians with the U.S. Department of Agriculture. The Agricultural Research Service has a whole host of taxonomists that specialize on different insect groups and plants. They have a whole host of botanists. They rely on Smithsonian taxonomists that are entomologists as well as botanists and plant pathologists. So there's a whole army of folks that specialize on these various groups of insects, plant pathogens, weeds and plants in general.

  • 13:10:22

    NOWIERSKIAnd then, so they rely on them to get feedback. And if they find out that it's something that's exotic, that it's not approved for shipment into the U.S., et cetera, then they hold the shipment. They essentially seize it. And then back it goes or they destroy it. But unfortunately they can't check every shipment. So there's always a few that make it through. And the most active ports of entry, like Miami and Los Angeles and New York and those sorts of areas -- especially if it's in a climate that's more salubrious, like a Mediterranean climate or even a tropical climate -- those sorts of ports of entries tend to get the most arrival of things that may have a great chance of establishment.

  • 13:11:08

    NNAMDIAnd once they make it in, Mike Raupp is here to tell us where they are, what they are and what they're doing. Mike, as our trading patterns change, how does it affect the invasive species that arrive in the United States?

  • 13:11:19

    RAUPPWell, you know, the history of this goes back a long way, Kojo. We had our first forest or tree pest actually in about 1635. That was the codling moth. And by that time, Johnny Appleseed had distributed apple trees all over the eastern United States. And by golly, that was the first pest in. The real tipping point came in the 1860s. This was the age of the industrial revolution. We now had iron-hulled ships and the steam engine. So the trip across the Pacific Ocean was reduced from a matter of weeks to a matter of days.

  • 13:11:56

    RAUPPIt spurred a very intense period of exploration for new ornamental plants, for new crops, for new varieties. And with this influx of new crops came the pests. This is when we went from a gradual increase in pests to what we call the hockey stick, an exponential increase. And we still are right in that exponential increase to this very day. We have more pests coming in daily. The rate remains the same. It's an exponential increase.

  • 13:12:32

    NNAMDI800-433-8850. What stink bugs have you found in your house? What stink bugs have found their way into your house? 800-433-8850. Bob, anyone who has traveled abroad is familiar with the process of declaring any food or plants we bring -- we're bringing home and then going through customs inspections at the airport here after landing. You've already indicated what customs is looking for. At both the seaport and the airport, however, what happens to the bugs that turn up in luggage or in cargo?

  • 13:13:05

    NOWIERSKIOkay. It's kind of a two-step process. We have the Customs and Border Protection that will funnel through your luggage. If they have additional questions, there are usually Animal-Plant Health Inspection Service, Plant Protection Quarantine officials. This is an agency that's part of the USDA that also provides a regulatory role and also a backup for -- if there's anything abnormal in these shipments that deals with plants, such as weeds or invasive arthropods or plant pathogens. So the two kind of provide a tandem.

  • 13:13:45

    NOWIERSKIAnd then APHIS PPQ or the Animal-Plant Health Inspection Service Plant Protection Quarantine also reviews permits, as does Customs and Border Protection, because people are constantly trying to get new plants -- exotic plants in to be able to market them in the U.S. or around the world. And then also we have biological control agents that we're trying to get in, which is one of the more environmentally-friendly approaches to manage invasive weeds and arthropods and even plant pathogens.

  • 13:14:22

    NOWIERSKISo those have to go through a very rigorous process of years of testing -- sometimes four to ten years it takes for, say, a bio-control agent like an insect or even a pathogen on a weed, has to go through all kinds of host-specificity testing to make sure it's focused only on that target weed and at most a few select relatives. And that's it, or it doesn't get approval. So APHIS is looking for permits that demonstrate that this has gone through that careful testing. It's been approved for introduction and release in the areas in the U.S. or North America, where these weeds or arthropods may be problematic.

  • 13:15:03

    NNAMDIIn the case of the mystery moth at the Baltimore Port, NPR reports that the inspector captured the insect, put it into a little glass vial and shipped it off to the experts at the U.S. Department of Agriculture. But what if it's the case that it's a well-known invasive species? Do they sometimes just exterminate it on the spot?

  • 13:15:20

    NOWIERSKII would guess that -- that'd probably be a good approach. So they have autoclaves and they have incinerators and other sorts of things that they can do. Or they can put it in alcohol. Or they can even freeze it. So...

  • 13:15:34

    NNAMDIPutting it in alcohol doesn't sound like such a bad fate. But that's another story. Mike, you studied the brown marmorated stink bug...

  • 13:15:42


  • 13:15:42

    NNAMDI...which is an invasive species from Asia.

  • 13:15:44

    RAUPPIt is. Yes.

  • 13:15:45

    NNAMDIWhat's the history of its arrival in the United States? And have you brought any today?

  • 13:15:48

    RAUPPOf course I've brought some, Kojo. Here they are right here on this little...

  • 13:15:51

    NNAMDISo excited to be brought here.

  • 13:15:52

    RAUPPI know. This guy got so excited, this little one, it actually molted. When it heard I was coming down, it went from the second instar to the third instar. It's gorgeous.

  • 13:16:02

    NNAMDIThat's -- that's the effect we have on these...

  • 13:16:03

    RAUPPI know.

  • 13:16:04

    NNAMDI...brown marmorated stink bugs.

  • 13:16:05

    RAUPPThat's "The Kojo Nnamdi Show." There you have it. But, yes, this one we believe came in sometime in the middle 1990s perhaps, which was actually a very important decade, because that was also the time that the Asian longhorned beetle and the emerald ash borer, we believe, arrived here in the United States. This one showed up first around Allentown, Pa. It's been moving outward ever since. It's now in more than 41 states. It's in Canada as well. And this has become a serious pest. Back in 2010, I think, we had $37 million of damage to our apple industry alone here in the Northeast.

  • 13:16:44

    RAUPPThis is a guy that's going to feed on your plants. It's going to feed on your tomatoes outdoors and your trees in your landscape. And then it's coming inside your home.

  • 13:16:53

    NNAMDIWhy? Why do they want to come indoors? And what's the extent of the damage they cause?

  • 13:16:57

    RAUPPWell, you know, let's start with the damage first. The damage -- these are sucking insects. These guys have a proboscis, a beak, that they put into the plant. They secrete proteolytic enzymes that break down the tissue. And then they slurp back up the predigested food. So on things like apples and peaches and tomatoes, they're going to cause a lot of damage on these things. We also found something very bizarre. They will actually feed through the bark of several of our landscape trees and shrubs. And also they'll feed on the fruit and developing (word?) on these trees.

  • 13:17:34

    RAUPPSo now the trees in your landscape, the plants in your garden become breeding sites for these insects that are going to enter your home. Now there's a common misbelieve that they enter homes to get warm for the winter. That's not...

  • 13:17:48

    NNAMDIThat's not the reason?

  • 13:17:49

    RAUPPNo, sir. I guarantee it, six...

  • 13:17:51

    NNAMDIIt's the pleasure of my company?

  • 13:17:52

    RAUPPThey love your company. They actually are -- it's more like a gimme-shelter phenomenon here. Remember 60 million years ago, there weren't a lot of big McMansions for these guys to get into. So what they would do is wedge themselves underneath the bark of the tree or perhaps in a rock crevice, chill out for the winter, when there was no longer food. And then in springtime, when the weather warmed again and there were leaves and fruit on trees, they would emerge and -- from these overwintering sites, and go out and resume their lifecycle.

  • 13:18:28

    RAUPPYour house looks like the bark -- this is no offense, no offense taken here -- looks like an excellent place to wedge in, spend the winter, chill out and then emerge. The problem is, as your home warms up in February and March, that's when they become active. And this is when they'll move out of your attic or from beneath your siding and they'll begin to stack up on those windows inside. So they really come in to seek shelter, a place to overwinter, protected from the wicked winter and also from their predators.

  • 13:18:58

    NNAMDIOver the winter, researchers in Virginia reported that stink bugs that they were studying seemed to have a hard time surviving that polar-vortex cold that we had. Now that summer's here, is there any evidence that the harsh winter reduced the stink-bug population?

  • 13:19:12

    RAUPPIt's an excellent question. The jury's still out on this one. One of the important factors for these stink bugs, Kojo, going into winter, is their nutritional status. In other words, like a bear, if they're full of fat, if they have lots of reserves, they're much more likely to be able to survive that winter period of non-feeding. It could be that some of the populations studied down in Virginia actually might not have had quite the reserves to be able to withstand that cold of the polar vortex. Whereas the stink bugs in my attic must have gotten very fat, because they survived just fine.

  • 13:19:51

    RAUPPSo we're still waiting to see. But in general, the stink bugs have shown up later this year, in part due to the cool spring that we enjoyed. And my impression is, the numbers are actually a little bit lower than they were back in 2013. So perhaps the polar vortex did put a little bit of the beat down on these guys. And that would be a very good thing.

  • 13:20:14

    NNAMDIThat may not be the case for John in Falls Church, Va. John, you're on the air. Go ahead, please. Hi, John. John, are you there? One more try for John. Okay. In that case we will go to Gloria in Davidson, Md. Gloria, you're on the air. Go ahead, please.

  • 13:20:34

    GLORIAExcuse me. Thanks. I'm so fascinated by this because I've been watching, collecting them and I see their little babies. And then they get to-- I've been saving them, little babies and then a little older and then teenagers and that kind of thing. And so is there a way to have -- has your guest written a book or pamphlet or something? I would love to get it.

  • 13:21:05

    GLORIAAnd I do have a question about the temperature...

  • 13:21:08

    NNAMDIYou mean a book specifically about stink bugs?

  • 13:21:11

    GLORIAYes, yes.

  • 13:21:12

    NNAMDIHere's Mike Raupp.

  • 13:21:12

    GLORIAAnd I just wondered about the change of the -- I was thinking that maybe the stink bugs got confused or whatever by it being cold and then hot and then cold and then hot and that kind of thing there seem to be changes.

  • 13:21:26

    NNAMDIWhy do you find them so fascinating?

  • 13:21:29

    GLORIAWhy do I? Well, it was because I was infested with them here. And I thought I'd better get to know them. And so I now have the magnifying glass. I pick them up with a grabber and put them on a thing...

  • 13:21:45 them.

  • 13:21:45

    GLORIA...I would love to study them.

  • 13:21:47

    NNAMDIHere's Mike Raupp.

  • 13:21:48

    RAUPPWell, Gloria, right, they are fascinating. I'm watching these guys in my Petri plate at this very moment and they are astounding, you're right. I have not written a book on this. I've written several articles, some stories about the use of the stink bug traps and whether they might help control stink bugs. And found that probably your best scenario here, if you're going to use these stink bug traps, which will catch and kill stink bugs by the millions, their best placed far away from your plants. Because if you put this near your tomato plant they'll actually kind of hang around there and cause a little bit more damage.

  • 13:22:27

    NNAMDIWhat that you're holding your hand right now?

  • 13:22:29

    RAUPPThis is the stink bug trap. And you can see the little cadavers.

  • 13:22:32

    NNAMDII see them, yes, yes, yes.

  • 13:22:32

    RAUPPAren't they fascinating also? Yes. So we gave these -- we did a study last year with some of our master gardeners. We gave have of the groups stink bug traps and told them to put them near their tomatoes per the recommendations on the label. We gave another group, was a control group that had no traps. And we found the folks that had the stink bug traps indeed had more stink bugs in their gardens and more damage to their tomatoes. So these will catch vast numbers of stink bugs but please, Gloria, put them far away from those tomato plants and the things you're trying to protect.

  • 13:23:07

    RAUPPI think we'll have a video actually that you can go to following the show today, which will give you my take on how to manage these stink bugs in and around your home. I think the producer said that would be available. So you might want to watch that YouTube.

  • 13:23:24

    NNAMDIAnd yes, you will be able to find that at our website Right now we're going to be taking a short break. When we come back we'll be continuing this conversation. But you can still call us at 800-433-8850 with your questions or comments about invasive bugs. You can send email to or shoot us a tweet @kojoshow. I'm Kojo Nnamdi.

  • 13:25:37

    NNAMDIWe're talking about invasive bugs with Bob Nowierski. He's an entomologist and national program leader for Bio-based Pest Management at the USDA's National Institute of Food and Agriculture. He joins us in studio with Mike Raupp the Bug Guy. He's a professor of entomology at the University of Maryland. We're taking your calls at 800-433-8850. Bob, in the Rocky Mountains, the bark beetle is an invasive species that's damaging lodge pole pine trees. How did it arrive and how is it causing a chain reaction that affects the drinking water?

  • 13:26:11

    NOWIERSKIWell, actually it's a native insect species, the mountain pine beetle, and its populations have been exasperated by climate change. So they've driven this insect into more frequent outbreaks and larger outbreaks. And so I think the latest tally is something like 112 million acres of pine trees have been destroyed by this beetle. So what it essentially does is it attacks the (word?) of the pine trees and it really prefers a lodge pole pine.

  • 13:26:45

    NOWIERSKIAnd it has an aggregation pheromone. So as it enters the bark tree it puts out a little perfume that attracts other bark beetles and gives them the signal, come and get it. And so they mass attract these trees and overwhelm it. And in the process of attacking the tree, they cut off the floum or the nutrient supply to the tree and it eventually ends up killing it. But in the process of entering the tree, it also is accompanied by a fungus that ends up attacking many of the trees which causes dehydration and actually reduces their defenses. So they're more susceptible to the bark beetle.

  • 13:27:24

    NOWIERSKIAnd so climate change has increased the rate of reproduction of these beetles. It's increased their rate of development. So they used to have -- maybe they'd have one generation per year and now they have two generations a year. So more beetles, faster reproduction, it's resulted in more frequent and larger outbreaks now.

  • 13:27:48

    NOWIERSKINow what is the effect on the tree? Once the tree begins to die, its needles start to weaken and they eventually drop off. And without needles to hold the snow, the snow then hits the ground and then it evaporates more -- it, yeah, it evaporates more quickly and doesn't stay on the ground as long. So there's quicker runoff and less of a water supply. And then the needles taint the water supply. So they make the water distasteful. And they even have some heavy metals that are associated with the needles that further may cause some toxicity in the water supply. So it really has to be reprocessed to make it drinkable. And so it's had a devastating impact on the Rocky Mountain watershed.

  • 13:28:39

    NNAMDINow that is a native species however.

  • 13:28:40

    NOWIERSKIIt's a native species.

  • 13:28:41

    NNAMDIMike, there are invasive beetles that have destroyed trees in our region. How did the Asian longhorn beetle and the emerald ash borer get here and what damage are they causing?

  • 13:28:50

    RAUPPWell, we think these guys were hitchhikers. They came in probably much the same way that our brown marmorated stink bug did. That's a good stowaway. This is a little bit different because the larvae of these particular beetles are what we call wood borers, Kojo. So oftentimes when they crate up big factory parts, valves, steam fittings, things like this, they'll use a very low grade lumber to build these crates or the pallets on which they're shipped.

  • 13:29:17

    RAUPPIt turns out as these containers sail across the ocean from Asia, inside those crates are smaller crates. And inside that wood are the larvae of these beetles. So when these crates and cargo arrive here in North America, they open up a container and out flies a beetle. This is how we believe that the Asian longhorn beetle arrived in places like Chicago and New York. And the Emerald ash borer came in in about 2002, probably a little bit earlier. That's when it was discovered. But sometime in that window I talked about, that 1990s period into Detroit.

  • 13:29:57

    RAUPPFrom there they've dispersed out across the nation. Emerald ash borer has now killed more ash trees than there are people living in Washington, D.C. and New York City. And so on the march it's in 42 states and two provinces in Canada. The worry here, much like Bob has said, do you know how many ash trees there are in North America, Kojo? Take a guess.

  • 13:30:21

    NNAMDINo, I can't even guess.

  • 13:30:24

    RAUPPTake a wild guess.

  • 13:30:25

    NNAMDIHow many ash trees there are?

  • 13:30:27 North America.

  • 13:30:28


  • 13:30:34

    RAUPPThat's pretty close, but we think it's about 8 billion. Eight billion, so right now we have 8 billion ash trees at risk. The ecological damage, the loss of these ash trees in our cities is one thing. And we've already lost some 40 plus million. But 8 billion trees at risk, it's going to dramatically alter our ecosystems if we can't find a way to stop this thing.

  • 13:30:57

    NNAMDIWell, I was close. Here's Don in Annapolis, Md. Don, you're on the air. Go ahead, please.

  • 13:31:04

    DONYes. Basically I actually worked on emerald ash borer program, but what I did was find ash trees and then find which ones were infected. And we would harvest the larvae. We would try and inject some of the trees and try insecticides, this, that and the other. But I guess the whole thing started out that -- I guess you well know, that the reason they got to Maryland, some trees -- the mission was quarantined but they shipped trees into Maryland anyway. And all of a sudden we had them.

  • 13:31:35

    DONAnd I guess we started out by we knew what nursery they were at and we tried to build a fire line around that nursery by cutting down every ash tree within a two-mile radius just about. But of course that didn't work because the wind blew them and everything else so...

  • 13:31:50

    DONBut anyway, also I guess I've worked on invasive snails in Baltimore Harbor where we actually harvested the snails off the railroad track just so you had a -- they spray it they would hitchhike on the rail cars that came into the Baltimore Harbor. And, as you said, get dispersed all over the country on railroad cars.

  • 13:32:08

    RAUPPThat's crazy. So those snails could really move fast, couldn't they?

  • 13:32:12

    NNAMDIIf they were boarding trains.

  • 13:32:14

    DONOh yeah, they'd get on -- you'd go out there, they'd be all over the tracks. And you'd even see them on the rail cars themselves. And I'm not sure -- because again my job was just find them and harvest them. You know, what they were doing about it I have no idea. I'm just stating my part of it. But, you know, I'm not a conspiracy guy but I've always though, does anybody ever think about the fact that maybe some of these invasive insects are sent in this country intentionally to cause those problems?

  • 13:32:39

    NNAMDII'm sure a lot of people think about that, Mike Raupp.

  • 13:32:44

    RAUPPYou know, Don, it's a very interesting question. I think the best case study I'm aware of is the one involving eucalyptus in California. Eucalyptus was brought in again during the late 1800s. And it went for almost a century without a single pest on it. Then suddenly during the era of the 1960s on out, there was basically one or two new pests of eucalyptus every year. And there's actually been a paper written suggesting that some of the folks that really don't like eucalyptus that consider it an invasive species perhaps were actually importing these pests to try to rid California of the eucalyptus tree.

  • 13:33:29

    RAUPPSo I'm not big on conspiracy theories anyway but I will tell you there's at least one paper that would suggest this could indeed be the case. How diabolical is that?

  • 13:33:40

    NNAMDIBack to beetles, here's James in Laytonsville, Md. James, you're on the air. Go ahead, please.

  • 13:33:46

    JAMESGood morning. I'd like to make one comment and report on one little situation. When the (word?) shield beetle stink bug first arrived, we were sucking it off the side of our house by the bucket loads with my shop vac. This year we see maybe one or two a day. Just an observation. I have no idea why. It seemed to like the south side of our house more than the north side of the house.

  • 13:34:12

    NNAMDIBut this year they don't seem to like it quite as much.

  • 13:34:15

    JAMESThis year I haven't seen very many at all. You know, it's just like any other bug. We just see one or two a day maybe.

  • 13:34:20


  • 13:34:21

    JAMESMy next comment is since the American chestnut tree, you know, was destroyed by the Chinese blight, I've been interested in invasive species and things like that. What I'm wondering is, have we ever exported any invasive species to someplace else from America -- from North America that is threatening stuff in some other continent?

  • 13:34:45


  • 13:34:46

    NOWIERSKIYeah, one of the favorites of Europe and into Eurasia a little bit is the ragweed or ambrosia. So that's a very problematic weed that we exported. We also have the corn root worm that was introduced into Europe that's causing devastating crop losses in the Ukraine and other areas. So those are two examples, one on the weed side and the other on the insect side.

  • 13:35:16

    RAUPPThere's a pest we have here, James, it's fairly innocuous. It's out there working right now in our trees. It's called the fall webworm. It makes a little nest on the (word?) of the branches here. It's pretty innocuous because it's controlled by a whole complex of natural enemies that attack it. In China there's a moth called the white moth which has now become the number one pest of their forests. That is what we call fall webworm.

  • 13:35:40

    RAUPPSo it's kind of tit for tat. We do trade back and forth. It's pretty much a global economy. And what that translates into I think, James, is a global biota. I think we now share a world biota. And that's really what we're talking about I think.

  • 13:35:57

    NNAMDIJames, thank you very much for your call. Bob, in many cases nonnative species are harmful. But you're actually been involved in importing some nonnative bugs on purpose to prey on invasive plants that are damaging ecosystems. How does that process work? There was a piece in today's New York Times along similar lines.

  • 13:36:16

    NOWIERSKIYeah, there was an article on saltcedar that's damaging especially the water supplies and some forage damage in the southwest that they've imported little beetles called diorhabda that feed on the leaves. And so they defoliate the plant. And after a number of years of defoliation it eventually kills the plant. Now some of these are a little bit controversial. Now if the weed doesn't have any relatives, any other plant species that are related to it, it's an easier target. If it has just one reproductive mode, just reproduces vegetatively, those are easier targets. They tend to be more genetically similar or homogeneous.

  • 13:37:02

    NOWIERSKIBut when they have sexual reproduction, so they produce seed as well as they reproduce by stolons or rhizomes, the underground roots that spread laterally, boy, look out. I worked on a weed called leafy spurge that had all those characteristics, lots of native relatives. And it spread by seed. In fact the seed capsules would (word?) or fire.

  • 13:37:28

    NOWIERSKIAnd when I was a professor at Montana State I brought a bouquet of this back to my office. And I knew I had to work on this weed since it was so problematic in Montana and the northern Great Plains. And I was concentrating reading a paper and I got hit in the face. And I'd go, you got to be kidding me. This plant has some character.

  • 13:37:49

    NNAMDIPlant has some -- it sounds like personality.

  • 13:37:51

    NOWIERSKISo we went -- we were involved in the process of providing resources through our nocuous weed trust fund to Montana to help screen new natural enemies. And most of these tended to be flea beetles or other foliage -- or stem borers and those sorts of things. But the flea beetles turned out to be most successful. And some of them preferred certain habitats more dry, sandy (word?) soils with more spindly leafy spurge versus others, had a broader ecological amplitude and could work in dry sites and more moist sites with heavier spurge and you name it.

  • 13:38:30

    NOWIERSKISo -- but the process of getting natural enemies is a very lengthy one again. So you have to do the whole specificity testing to make sure they're very focused on the target weed and at best a few close relatives.

  • 13:38:44

    NNAMDI800-433-8850. How do you deal with invasive bugs in your yard? You can also send us email to Mike Raupp, our least favorite bug of summer is probably the mosquito. And it has an invasive cousin that's taken up residence here, the Asian tiger mosquito. How did it get here? What's being done to combat it?

  • 13:39:06

    RAUPPYeah, this was another nasty story. Recently we've had -- over the past 20 or 30 years we've had a real influx of these pests from Asia. You know, we talked about the emerald ash borer. Again this is an Asian pest. And the damage every year is running about $1.6 billion it's costing us every year, this particular pest, the Asian longhorn beetle, the brown marmorated stink bug. But to cap it all off we've got -- well, mosquitoes used to bite us at dawn and dusk. You'd go out in the garden and you'd be working but you didn't have to worry. Unless it was dawn or dusk you were not being bitten in the middle of the day.

  • 13:39:45

    RAUPPThat all changed in the late 1980s...

  • 13:39:48

    NNAMDISure did.

  • 13:39:48

    RAUPP...when the Asian tiger mosquito invaded our realm. It was brought in through one of the southern ports. I believe it was Mobile, Ala. in a load of tires to be recycled from Asia. Now, the tires were full of water. The water was full of mosquito larvae and, hence, we got the Asian tiger mosquito, which is a day biter.

  • 13:40:12

    RAUPPThe other problem here, of course, is the Asian tiger mosquito is one of those bad performers that's on the list of mosquitoes that convect our West Nile virus. So in addition to just being a nuisance, now we have additional concern that this may be implicated in the transmission cycle of West Nile virus.

  • 13:40:34

    NNAMDIOn to the telephones again because Joseph, in Springfield, Va., I think has a suggestion for us. Joseph, you're on the air. Go ahead, please.

  • 13:40:43

    JOSEPHOkay. Reducing the stink bug or other bugs on the tomatoes or on the green beans -- this is organic, old method, that you spray with flour. And the flour gets into the legs of those insect and overnight get a little wet and become hard. They cannot move any longer and they die.

  • 13:41:05

    NNAMDIMike Raupp?

  • 13:41:05

    RAUPPI like it. If you think it works and you've…

  • 13:41:09

    JOSEPHI try it every year…

  • 13:41:10


  • 13:41:11

    JOSEPH…on my green beans…

  • 13:41:12


  • 13:41:12

    JOSEPH…on the tomatoes. And I suggest it also the Amish people…

  • 13:41:17

    RAUPPVery good.

  • 13:41:17

    JOSEPH…that they try it on their green beans.

  • 13:41:19


  • 13:41:20

    RAUPPThere's another fairly organic product. It's called Kale and Clay Surround. And it has a very similar motive of action. It acts as an abrasive. We also just published a paper where we evaluated several of these commercially available retail-store type products. These are called ready-to-use. These are the kind of things you would buy and squirt. And we found that Safer's Insecticidal Soap and also some of the horticultural spray oils were very effective in killing the little nymphs -- those little tiny black guys that you see.

  • 13:41:57

    RAUPPIt's tough to kill the adults, but if you can treat your tomatoes when this stinkbug is in the nymphal stage -- and some of these products, including insecticidal soap actually had ovicidal activity. That means that if the eggs are on your tomato plants and you treat them, you'll probably kill eggs as well. And this is good news because these kinds of compounds are very benign to the pollinators and the other beneficial insects that you're going to find in your vegetable garden.

  • 13:42:26

    NNAMDIJoseph, thank you very much for your call.

  • 13:42:28

    JOSEPHThank you, thank you.

  • 13:42:29

    NNAMDII want to move on to Ken, in Gaithersburg, Md., who wants to know how to get rid of them, I guess, indoors. Right, Ken? You're on the air. Go ahead, please.

  • 13:42:37

    KENYes. Thank you. Can you hear me?

  • 13:42:39

    NNAMDIYes, we can.

  • 13:42:40

    KENOkay. Yes. I have a stinkbugs indoors. And although my cats think they are great fun, it interferes with their digestion and I end up cleaning up after the cats.

  • 13:42:50

    RAUPPUh-oh. That sounds very unpleasant, Ken.

  • 13:42:52

    KENSo how can I get them the heck out of my house?

  • 13:42:57

    NNAMDIMike Raupp?

  • 13:42:57

    RAUPPWell, you know, the best thing -- the thing I like to think about on this, Ken, is anything that's going to be good for energy conservation for your home is going to help keep those stinkbugs out. So caulking, any place where utility runs in and out, your electrical service, your air handler, your air conditioner, foam those places up. What I do is I go up into the attic -- my home has gable-end vents on it. Put window grade screening on those gable-end vents. And if you have soffit vents and you can convince somebody to go up in the attic and screen off those soffit vents, this will help keep those stinkbugs out of your home.

  • 13:43:36

    RAUPPOnce they're in your home, I think the easiest thing to do is either vacuum these up with a shop vac or a little Dust Buster or something this, get rid of the bag so they're not stinking up the closet where you keep the vacuum. Or the other thing I do is just take a water bottle. I'll clip the top off water bottle, invert it. Now I've got a little funnel. And if you fill that with soapy water and hold it underneath the stinkbug, they have a great desire to kind of jump off the wall and commit suicide in that little bucket of water.

  • 13:44:09

    RAUPPIt's quite entertaining, almost as much fun as watching the cats chase these things, but it's a really excellent way to get rid of the stinkbugs. Once they're dead, I simply take them outside, add them to my compost and return them to the circle of life.

  • 13:44:23

    NNAMDIWe're going to take a short break. When we come back we will continue this conversation on invasive bugs and take your calls at 800-433-8850. You can send email to I'm Kojo Nnamdi.

  • 13:46:30

    NNAMDIWelcome back to our conversation on invasive bugs. You should know that you can see a video on our website with Mike Raupp explaining all of his tricks for getting rid of stinkbugs. That's on our website, Mike Raupp joins us in studio. He is a professor of entomology at the University of Maryland, also known as "Bug Guy."

  • 13:46:48

    NNAMDIHe is joined by Bob Nowierski, who is an entomologist and national program leader for Bio-based Pest Management at the USDA’s National Institute of Food and Agriculture. Bob, one way to cope with invasive bugs in the realm of agriculture is to use what's called integrated pest management. What is it? How does it work?

  • 13:47:05

    NOWIERSKIWell, integrated pest management uses all the available tools to manage pests in the most environmentally-friendly and economically-friendly and also sustainable fashion. And so what we use are tools like biological control. We use cultural management where we can. So if we're talking about crops, you can rotate crops or interplant some things that might provide refuge for natural enemies that will work into the cropping system. We can plant early. We can plant late to avoid a pest that's feeding on a crop.

  • 13:47:39

    NOWIERSKIWe can harvest early. We can harvest late. All these are various tools. We can use host-plant resistance. So we can have -- produce some plants that have little hairs or trichomes that produce sticky compounds. So if a bug's walking across, they get stuck and they can't lay eggs. And eventually they'll die on the plant -- some of them. Tomatoes have these glandular trichomes, for example. And then we can also use pesticides.

  • 13:48:08

    NOWIERSKINow, there are some more friendly pesticides than others. Some of these are called neonicotinoids and insect growth regulators. Now, you also have to be careful with the safer reduced-risk pesticides because some of these have non-target impacts on pollinators and also natural enemies, like predators and parasitoids. And so sometimes it's unavoidable to use a pesticide.

  • 13:48:34

    NOWIERSKIAnd I can think back in my days back in Montana, when I was on the county wheat board and I actually encouraged the county to be able to provide a cost-share for bugs. Why not? They were doing it for herbicides, why leave our good guys out? So we got cost-share for people to be able to have bugs purchased by the county and then they were released against leafy spurge and spotted nap weed and some of these other problem weeds.

  • 13:49:00

    NOWIERSKIBut there are areas along roadsides that had weeds that were problematic and they had no bio-control agents available for them. So the landowners had an option of either pulling these out, if they didn't want anything to be treated, or let the county do it. And so we talked the county into providing a couple of different kinds of spray booms and tanks so that we could do selective spraying and be careful about groundwater levels, how deep the groundwater was.

  • 13:49:29

    NOWIERSKIAnd then to replant, we engaged the soil conservation service to give us some ideas of what would be the optimal mix of seed that we could replant following herbicide application. And so integrative pest management, again, integrates all of these tools in the pest management tool box, but you choose the most environmentally friendly and sustainable and economically feasible options first, and then you expand from there.

  • 13:49:57

    NOWIERSKIBut, again, some of these things are so new -- if we're talking about a spot infestation of a brand-new weed, you can't wait for bio-control. You need to get on it with an herbicide and eliminate before it becomes a problem. But once these weed infestations become so large it becomes not economically feasible to apply an herbicide, so then we integrate herbicides in the spot infestations and around the periphery to contain an infestation. And then use bio-control and sheep grazing and other approaches in the middle.

  • 13:50:27


  • 13:50:28

    NOWIERSKISo that's an example of integrated pest management.

  • 13:50:31

    NNAMDILynn, in Annapolis, Md., however, wants us to think into the future, I think. Lynn, you are on the air. Go ahead, please.

  • 13:50:37

    LYNNHi, Kojo. I love your show and you're a remarkable person. And thank you for having a show today. Just a quick comment, it's not specific, but I was listening in my car and have been doing a lot of reading. I'm a science environmental teacher by training. And I've been a park ranger as well. And the Iroquois Nation that was here in the eastern part of North America when Colonial Europeans sailed up the Bay not too long ago -- because I'm getting old now.

  • 13:51:07

    LYNNThey devised a wisdom that said that when we do things we need to consider the next seven generations. And there's a healthy series of home-care products called Seventh Generation and named after that idea. But I just -- when I was a park ranger I watched people go out in the woods with gunny sacks and take box turtles for export in the pet trade to places like China where they were…

  • 13:51:38

    NNAMDIAnd today?

  • 13:51:38

    LYNN…considered an exotic pet. And I just -- there are not very many left.

  • 13:51:42

    NNAMDILet me have Mike Raupp address that. Mike?

  • 13:51:45

    RAUPPYeah, I think there's enormous wisdom in what you've said here, Lynn. I think that's really what's at the heart of these kind of careful decisions that Bob has spoken about. You know, what will it mean to our ecosystems when we introduce a new biological control agent? What impact will it have? And, again, this all has to be weighed against this very new paradigm, where in an unprecedented experiment in the history of this planet, the movement of species between continents is a natural phenomenon, but it happens over eons.

  • 13:52:23

    RAUPPWhat we've done is compressed these eons into decades or in certain cases, years. So now it's an entirely new world. So we have to weigh these kinds of very difficult decisions. The inactivity -- or not to deal with a pest like Emerald ash borer may change dramatically the shape not only of our natural forest, but of the hundreds of thousands of trees that basically shade our cities and provide eco-system services. So what is the best mix?

  • 13:52:57

    RAUPPYou know, the -- again, it's a very difficult issue. We don't want to rush into something. But, again, what price is inactivity when we have this continuous onslaught of these egregious, lethal invasive species. So it really is a dilemma.

  • 13:53:14

    NNAMDIBefore you leave here today, you brought some other species with you. You brought some other bugs with you. Can you give us a rundown of exactly what I'm looking at?

  • 13:53:22

    RAUPPYeah, one of the -- these characters right here, this is gypsy moth. This is one actually which I'm very closely familiar with. This is the one they actually hired me to work on, some three decades ago, to help people understand the biology of this particular pest. And also to implement these kind of integrated pest management programs that Bob talked about earlier. This continues to be a problem.

  • 13:53:54

    RAUPPIt's causing about $240 million annually, in terms of costs to try to eradicate it, contain it, the loss to the value of trees around people's homes. So this is a very expensive one. I've got another -- and for those of you who can't see…

  • 13:54:11

    NNAMDIThey're all so attractive.

  • 13:54:11

    RAUPPThese are beautiful. They -- these particular insects --I brought some to studio with me today. It's unfortunate you can't see them because they really are gorgeous. This is the Asian longhorn beetle. This is the one we spoke of earlier. It's a major pest of our shade trees, particularly in cities like Chicago, New York, New Jersey, places in Ohio. One of the big concerns now, it's in New England. And there's a great concern that it's going to move over to the maple trees, which are one of the favorite hosts.

  • 13:54:43

    RAUPPThe whole sugar maple industry in New England is concerned about this one. And to try to manage this particular pest, the price tag on that one is about $200 million a year to try to deal with this particular pest and the lost property values. So we're in a time I think the -- Bob, you might correct me on this, but I think the estimate is something like $120 billion a year invasive species are costing this country in terms of trying to eradicate them, trying to reduce their damage, trying to manage these pests. So these come with an enormous price tag.

  • 13:55:20

    NNAMDII'm glad you mentioned the economic impact because, Bob, how would you describe the trajectory for more -- for invasive species of bugs? Are we seeing more as international trade and world travel increase?

  • 13:55:31

    NOWIERSKII think they go hand-in-hand. And we just have to be more and more vigilant. And unfortunately our resources are really stretched these days with budget difficulties, etcetera. So I don't see a lot of additional folks being added at all our ports of entry. In fact, possibly the converse.

  • 13:55:50

    NNAMDIWe've got an email from Sarah, who said, "My problem is centipedes. I've had this problem since I moved into my house in 2009. It's better than it was. I've had treatments from Orkin and am now using an independent exterminator, but I'd like to get rid of the completely. Although, I imagine their harmless, I'm pretty unhappy when I wake up in the night and there's a creepy three-inch bug on the wall near my head. Any suggestions?"

  • 13:56:09

    RAUPPYeah, they creep me out, too. These are the guys with the really long legs. They're called house centipedes. If there's an upside on this -- I'm not sure if it's going to make you feel better -- but these are predators. And what they're doing is they're kind of murdering and cleaning up some of the other arthropods that have found their way into your house. These are denizens of the dirt. You'd normally find them outdoors in your flower beds. That really is their home.

  • 13:56:31

    RAUPPBut, again, one thing you might try is check your door sweeps, particularly if you have a walkout in the basement or perhaps around -- if you've got casement windows, try to caulk those windows. Try to replace those door sweeps. Again, your best bet is to try to exclude these guys. And if you have mulched beds, try to move those mulched beds about 18" away from your foundation. That creates a little no-man's land that these centipedes aren't going to like to cross to find a little hole to get into your bedroom and terrify you at 2:00 o'clock in the morning.

  • 13:57:06

    NNAMDII'll let Joseph, in McLean, Va., ask the last question. Joseph, you have about 30 seconds, but go ahead, please.

  • 13:57:10

    JOSEPHAll right. I want to know how important it is, really, to go after some of these species. Because nature naturally affords a vacuum and if there's a food source, it's going to after it. (unintelligible) the gypsy moth, the Japanese beetle, I don't see them as a problem anymore.

  • 13:57:30

    NNAMDIThirty seconds, Mike Raupp.

  • 13:57:31

    RAUPPYeah, here in the East, Joseph, we imported a fungal disease. It's called Entomophaga maimaiga, which basically has collapsed the gypsy moth populations. Along the front though -- if we moved out to Wisconsin and places like that, this thing is still roaring along causing a lot of injury. Japanese beetles have been down for several years, but with a couple wet springs that we've had -- hey, I got Japanese beetles all over the place in my yard.

  • 13:57:55

    RAUPPI've been murdering them by the hundreds. So, again, these things will cycle. You're right. Mother Nature will take care of these things, but unfortunately sometimes her solution takes a little bit of time.

  • 13:58:06

    NNAMDIMike Raupp is a professor of entomology at the University of Maryland, also known as the "Bug Guy." Mike, always a pleasure. And Bob Nowierski is an entomologist and national program leader for Bio-based Pest Management at the USDA's National Institute of Food and Agriculture. Bob, thank you for joining us.

  • 13:58:20

    RAUPPOur pleasure. Thank you.

  • 13:58:22

    NOWIERSKIIt's great to be here.

  • 13:58:22

    NNAMDIThank you all for listening. I'm Kojo Nnamdi.

Related Links

Topics + Tags


comments powered by Disqus
Most Recent Shows

The Politics Hour: July 10, 2020

Friday, Jul 10 2020Metro General Manager Paul Wiedefeld talks about the future of WMATA and what reopening will look like. And D.C. Councilmember Vincent Gray walks us through city budget and gives us an update on building a hospital east of the Anacostia River.

D.C. Police Reform, Past And Present

Wednesday, Jul 08 2020The D.C. Council's emergency police reform bans chokeholds and the use of pepper spray on peaceful protesters. But D.C. Auditor Kathy Patterson says these and other proposed measures are already on the books.