Guest Host: Diane Vogel

stink bugs

stink bugs

For some people the bugs of summer are pests to be avoided. For Mike Raupp, they’re creatures to be celebrated and studied. They’re also living sensors for our local environment. We explore the world of mosquitos, cicadas and “lightning bugs.”


  • Michael Raupp "Bug Guy" and Professor of Entomology, University of Maryland


  • 13:39:03

    MS. DIANE VOGELWelcome back to "The Kojo Nnamdi Show." I'm Diane Vogel, Managing Producer of "The Kojo Nnamdi Show" sitting in for Kojo. He'll be back tomorrow. For a lot of us the bugs of summer are pests to be avoided. We prefer to close the windows, patch the screens and hang out indoors around sunset. But not everyone feels this way. Some people, including our guest Mike Raupp, see the bugs of summer -- or, well, the bugs of any season, as creatures to be celebrated. They're fascinating in their own rights, but they're also fascinating as a kind of living sensor alerting us to all sorts of things about our environment, important things, things that we might not otherwise notice.

  • 13:39:46

    MS. DIANE VOGELSo what are the insect mysteries that are challenging Mike Raupp this summer? Well, he's wondering what's up with Monarch butterflies. I mean, they arrived on time, but in much smaller numbers than expected. And what about all those stink bugs? Where did they go? Is the stink bug invasion over or can we expect them to come back soon? And hey, what's with that 17-year cicada cycle, you know, the ones that are supposed to come back every 17 years? Why are they showing up this year in a corner of St. Mary's County? Mike Raupp is here, he's gonna join us and talk to us about all kinds of things bug related. You may know him as the Bug Guy.

  • 13:40:26

    MS. DIANE VOGELHe's a professor of entomology at University of Maryland, and he's very well known for his bug of the week website, which I encourage you all to check out. It's linked from our website. He's written numerous books about insects and bugs, and his most recent is a kid's book called "26 Things That Bug Me: A Special ABC." Mike, always a pleasure to see you.

  • 13:40:48

    MR. MICHAEL RAUPPOh, it's so exciting to be back, Diane. What a pleasure, and golly, how could anybody not adore those bugs out there?

  • 13:40:56

    VOGELIt is -- when you walked in, I knew I could trust you to bring something fascinating and oh, squirmy.

  • 13:41:02

    RAUPPWell, there they are, the stinkies. You know, I brought my stink bugs with me. They so enjoy getting out of those growth chambers in the laboratory because they know what's coming up next. So any chance to get out of the office, and they're here, but yeah. The stink bugs have been back and forth this year, Diane, and kind of on a little bit more serious note, they really have showed up to be, again, a pretty important problem, a serious problem for our fruit producers.

  • 13:41:30

    RAUPPThey've now kind of shifted a little bit out of apples and peaches, and they're starting to show up in places like sweet corn and vegetable gardens. I was in the community gardens this week, and they are there by the boatload, so a lot of stink bugs again this year.

  • 13:41:45

    VOGELNow, when we see stink bugs, a lot of times we see the stink bug carcass, I think.

  • 13:41:49

    RAUPPSure, mm-hmm.

  • 13:41:51

    VOGELYou know, people see them around their house, and I understand that from our point of view, we might think that they're trying to, I don't know, come in our house to feed or something.

  • 13:42:00


  • 13:42:01

    VOGELBut they don't. What is their story? Why are they in our gardens and why are they in our houses?

  • 13:42:07

    RAUPPRight. Okay. There's kind of a misconception that they're coming in to get warm in the wintertime. That's not really the case. What they're coming in for is refuge. They're in the -- in the natural world in a forest, they might find a great fallen tree, they might find a rocky outcrop, a protected place to kind of hunker down for the winter, chill out, and then when spring returns, when the earth warms, they'll leave these hibernation -- these over wintering sites, and move out into the vegetation to feed.

  • 13:42:40

    RAUPPWell, guess what, here in Bethesda, there aren't really a lot of big rocky outcroppings or fallen trees, so they're coming into your house. They simply want to find a refuge. They then move out. In the spring we saw this great exodus out of people's houses, back out into the landscapes, unfortunately into the fruit orchards, now into our crops, into our corn and vegetables. They're gonna feed, they're gonna fatten up.

  • 13:43:04

    RAUPPThey're gonna whip through one more generation, the numbers are gonna increase, and then when the temperatures start to cool, when the leaves start to turn, when the fruit starts to ripen and disappear, guess where they're showing up, Diane? It's your house again.

  • 13:43:18

    VOGELExactly. On every screen in every room...

  • 13:43:20


  • 13:43:21

    VOGEL...that is not protected.

  • 13:43:22

    RAUPPThat's how they roll, baby.

  • 13:43:25

    VOGELIf you have a question about summer insects, if you've noticed something different in your garden or in your yard or in your house, call and ask Mike about it. The number is 1-800-433-8850, or you can send e-mail to kojo K-O-J-O I know that one of the more serious bug-related issues that has happened recently is that the USDA has put our region under a federal quarantine, and they say they are worried about the Emerald Ash Borer. Tell us a little bit about that. What do I need to know?

  • 13:44:04

    RAUPPYeah. This is a real bad performer, Diane. This one was imported. First detected out in Michigan in about 2002. Probably came in with goods shipped from Asia in a container ship. It first arrived in our region in 2003 which a shipment of nursery stock that wound up in Prince George's County, and from there it's basically been Katie, bar the door.

  • 13:44:27

    RAUPPWe've been studying this thing. We thought it was gonna hit Baltimore in about 2022. Unfortunately, this year was its outbreak year. It was detected up in Howard County, 40 miles away from the infestation down in Brandywine. We knew it was knocking on the door of the district, and guess what, this year it got in. So the federal quarantine basically limits the movement of wood and wood products. Anything that might -- this beetle might hide, and this is a wood burrowing beetle, it gets inside trees.

  • 13:45:01

    RAUPPIt gets inside nursery stock. So the quarantine basically is designed to limit the movement of this thing and slow down the spread so our neighbors up in New Jersey, we're gonna take care of those guys in Jersey, and people in different states aren't going to receive a shipment that contains this Emerald Ash Borer. And this one is a hundred percent lethal to our ash trees. Diane, there are...

  • 13:45:24

    VOGELWhat does it look like? What should I be keeping my eye out for?

  • 13:45:26

    RAUPPThis -- oh, this is a beautiful animal. You're probably not gonna see the beetle itself until densities are very high. But people who have ash trees, the first thing to do is see if you have ash trees on your property, and there are numerous websites you can go to that will help you identify what an ash tree looks like.

  • 13:45:45

    RAUPPIf you see dieback in the canopy of your ash tree, that is, if you see dead limbs up there, that's when the first flag should go up. The second flag goes up when the woodpeckers come in. Now, this might seem odd to you, but think about this. Woodpeckers have spent 40 million years figuring out how to find borers in wood. They're very good at it. So if you see woodpeckers working on your ash tree, this is the light bulb number two that goes on.

  • 13:46:15

    RAUPPFinally, for diagnosticians, what we do is we look for their holes. These are like exit wounds in a body. We call them exit holes. When this beetle emerges as an adult it leaves a whole in three shaped like the letter D as in David. We have some native borers, but when they emerge, they leave a hole that's either round or oval. So if we see dieback woodpecker activity, and these D-shaped holes, it's almost a sure confirmation that we've got the dreaded green menace, the Emerald Ash Borer.

  • 13:46:47

    VOGELAnd what do we now do? Do we call an arborist, do we throw a net over the tree, do we have to say goodbye? Is there something we can do to save our ash tree?

  • 13:46:56

    RAUPPAbsolutely we can save our ashes, Diane. Absolutely on this one. No slips there. But there are some very potent chemicals which we can use. Even if a tree is infested, even if we see maybe 10 or 20 percent of that tree defoliated, we can still come in with a therapeutic chemical, treat that tree, and arrest that population build up. So we really can save our ash trees. The big problem is going to be in cities like Baltimore. Baltimore has 300,000 ash trees in it.

  • 13:47:30


  • 13:47:31

    RAUPPIt may cost as much as one to $2,000 to remove these ash trees. You do the math on this. We're talking about hundreds of millions of dollars once it arrives in Baltimore to simply deal with this pest or remove and replace those ash trees. That's where the big impact is gonna be. And, of course, once it moves out into our native forests where we have the, you know, the normal dynamics, the natural processes, it's gonna be very difficult to protect those ash trees out in nature.

  • 13:48:03

    VOGELWell, I want to get some of our callers in.

  • 13:48:05


  • 13:48:06

    VOGELSo let me go with Steven in Washington D.C. Steven, you're on the air.

  • 13:48:12


  • 13:48:12


  • 13:48:14

    STEVENI was talking to a friend of mine this morning who has just driven from Fort Collins, Colorado to San Antonio, up into Alabama, and he's now here in the District. The Colorado to Texas trip he used to make frequently when he was kid, and at every gas stop three or four hours apart, they would have to scrape windshield of all the bugs.

  • 13:48:35

    STEVENHe said he didn't have to scrape the windshield until they got to Alabama this time, and he's a little freaked out by the de-insectification of the country. And I'm wondering is it drought, is it Monsanto or insecticides or what's going on?

  • 13:48:50

    VOGELGreat question, Steven, thank you.

  • 13:48:51

    RAUPPGreat question, Steven, thank you so much. I don't think we need to point -- if we're gonna point a finger on this one, I think we'd point it to mother nature. The region he drove through, and I think you need -- you hit the nail on the head. It's the D-R-O-U-G-H-T right now. There's a pretty tight link between plant viability or plant vigor, and insect attack.

  • 13:49:14

    RAUPPIn some cases, insects like these borers really like trees when they get stressed, and they'll attack stressed trees. But the kind of bugs that would collect on your windshield or the grill of that car, many of our smaller flying insects are really gonna adversely affected by droughty conditions. It's been plenty buggy here in the northeast I think where we've have ample rain.

  • 13:49:37

    RAUPPI would suspect that your friend merely drove through a vast part of the country where the numbers of flies in particular -- the populations may be way, way down as a result of the drought. I think our ecosystems are okay, and these are -- these are kind of natural phenomenon I think. So no need to worry on this one, Steven, but thank you.

  • 13:49:57

    VOGELSpeaking of the natural phenomenon, I know that every August I look forward to the Monarch Butterflies.

  • 13:50:02


  • 13:50:03

    VOGELAnd I was surprised to see -- I have a number of butterfly bushes, and my neighbors do as well, so we usually get a really good turnout, a really nice colorful show. But this summer has been pretty lame. There -- I've seen a couple. Is there something going on with the Monarch Butterflies?

  • 13:50:20

    RAUPPYou know, it's a great question, Diane. I wonder the same thing. They really showed up early, and I think is probably part of global change. I think one of the things we've really seen in the bug world is everybody's advanced. So I actually saw my first Monarch a little earlier than I usually do. I think I saw these in the tail end of May, which is really quite early. But you're right. I'm watching my milkweeds very carefully right now, and frankly, they've been pretty skimpy in terms of production of those beautiful caterpillars.

  • 13:50:50

    RAUPPSo I really wonder if, again, maybe this is a drought phenomenon. You know, maybe the quality of the host, in other words, my milkweeds just don't look so hot. They look pretty yellow. I'm wondering if maybe it's a host quality effect that they perhaps just aren't as nutritious, or maybe this is just a better year for the predatory bugs, the natural enemies that would attack these beautiful Monarch caterpillars. So it could be a little of both here.

  • 13:51:18

    VOGELSo we understand the ecosystem story a little bit, the chain, you just said it's the quality of the milkweed. I think most of us don't realize that butterflies lay their eggs on an individual kind of plant. Every different butterfly has a different preference, and the pupa, I guess, is reliant on that plant. Tell us a little bit about that relationship between the milkweed and the Monarch Butterfly.

  • 13:51:41

    RAUPPOh, yeah. This is absolutely critical. You're absolutely right. The female will lay an egg on the plant. The egg hatches into what we call larvae. The tiny larvae then feed and will form the chrysalis from which emerges the next round of Monarch adults. Now, if the food quality is poor, in other words, if it's not nutritious -- pardon me -- it's the same as it might be for you and I. When we eat poor quality food, we're not gonna be healthy.

  • 13:52:08

    RAUPPIf the development of the Monarch larvae slows down, and it stays in this very vulnerable stage for a longer period of time, if it takes longer to develop because the food is not good, that gives the natural enemies, the bad guys, more of a chance to eat and kill this thing. So the host quality is vitally important in the success of the Monarch Butterfly.

  • 13:52:29

    VOGELInteresting. And I understand eating the milkweed makes the Monarchs kind of an untasty treat for the...

  • 13:52:36

    RAUPPOh, baby. They're full of something called cardiac glycocides. These are heart poisons. So when things like --if you were to eat a couple of these things, your heart might stop and you might croak, and birds find these very distasteful. They might eat them once, vomit, and never eat them again. So they learn pretty quickly to stay away from these things that are colored orange and black. Those are Mother Nature's warning signals. I suggest you do the same.

  • 13:53:01

    VOGELVery good advice, Mike Raupp, a man better known as the Bug Guy. He's a professor of entomology at University of Maryland, and is well known for his bug of the week website. He's the author of numerous books, most recently a kids' book called, "26 Things That Bug Me: A Special ABC," and you're listening to "The Kojo Nnamdi Show." I'm Diane Vogel sitting in for Kojo. I'm gonna go back to the phone and we'll go to Marcie in Columbia, Md. Marcie, you're on the air.

  • 13:53:31

    MARCIEHello, yes. Hello?

  • 13:53:33

    VOGELYes, you're on the air. Go ahead, Marci.

  • 13:53:36

    MARCIEGood afternoon. Yes. I have a question. I have always been very curious about something. Night insects whose natural habitat is in darkness, why do they flock to light all the time? It seems...

  • 13:53:51

    VOGELThat's a great question. That's a great question, Marcie. I'll let...

  • 13:53:54

    MARCIEI have -- I would love to find out.

  • 13:53:59

    VOGELWell, I think Mike has an answer for you.

  • 13:54:02

    RAUPPMarcie, wonderful question. Don't go the light. Don't go to the light. That's what we need to tell these guys. This is a very complicated story. I'll try to make it as simple as I can. Basically, night flying insects often use the light from distant stars and planets to navigate. In other words, they use the direct light beams to find a true course. Your light bulb, because it is a very close lighted object, the light rays that come from your light bulb are still diverging, in other words, they're no longer parallel because that's quite near.

  • 13:54:39

    RAUPPAgain, the light from the stars is fundamentally parallel. The light from a light bulb is still diverging. So what the moth does is correct and this correction turns the moth steadily toward the light, and eventually it spirals in with these corrections and winds up at your light bulb. So it disrupts the normal orientation pattern based on distant parallel light beams, it spirals in, winds up at your light, and unfortunately and they get toasted there. So this is the explanation I've heard. Quite curious I think.

  • 13:55:13

    VOGELInteresting. Ruth -- thank you, Marcie. I'm gonna go with one more call from Ruth in Herndon. Ruth, you're on the air.

  • 13:55:22

    RUTHHello. My question is about gnats. We're not able to put fruit out in our kitchen any longer, and also I've cleaned out the disposal with apple cider vinegar and baking soda to discourage gnats, but they're still there.

  • 13:55:43

    VOGELThey seem to be everywhere this year. I've certainly noticed a lot of them in the grass around my house.

  • 13:55:49

    RAUPPYeah. They're -- Ruth, good question. There are a couple different kinds of gnats. The one we see outdoors, we call chloropids. They're actually little gnats that breed an organic matter in soil. These are the ones that come up and buzz around your eyes in particular. They're attracted to the exudates in your sweat. The one we find indoor are usually fungus gnats, and you have done exactly the right thing.

  • 13:56:10

    RAUPPGet rid of all the fruit, look very, very carefully, see if maybe there's behind a garbage pail or a disposal somewhere you have a piece of fruit that might be still breeding these things. Throw that stuff out, get a fresh start. You did the right thing putting a disinfectant down your drain. They often can breed there. So you're on the right track, and I've got my fingers crossed that what you've done right now, Ruth, you may have licked this problem. So let's keep our fingers crossed on that one.

  • 13:56:38

    VOGELThank you, Ruth. I wanted to get back before we close, this goes so fast when we speak with you, Mike, always a pleasure.

  • 13:56:44


  • 13:56:45

    VOGELI wanted to ask you about the cicadas.

  • 13:56:47


  • 13:56:48

    VOGELWhat is with these -- is there a problem with the calendar, they don't understand 17 years versus 13 years?

  • 13:56:52

    RAUPPNo. No. No. No. Now, you know, these guys are just rocking. These are what we call our dog day or annual cicadas, and I don't know. These boys are just having a real cicada-palooza up in the trees. Now, these are not a periodical cicada. These are annual dog days. We're gonna see them every year, but for whatever reason, they just had a spectacular year this year.

  • 13:57:13

    RAUPPTheir full bore in my neighborhood. They are as loud as the periodicals were back in 2004. So no, nothing to worry about. This is just -- these are several different species, that's all.

  • 13:57:24

    VOGELSo everybody who's wondering about those incredible loud cicadas in their backyard, or their dogs who are eating the cicadas...

  • 13:57:31

    RAUPPYeah. A little extra protein.

  • 13:57:33

    VOGELExactly. Well, I know that you are a cicada lover, and we'll have you back to discuss many, many more bugs because there's never enough time. We had mosquito questions we couldn't get to, a million other questions, but Mike Raupp, thank you for joining us today on "The Kojo Nnamdi Show."

  • 13:57:48

    RAUPPAlways a pleasure, Diane, thank you.

  • 13:57:50

    VOGELMike Raupp is better known as the Bug Guy. He's a professor of entomology at University of Maryland, and has a great bug of the week website that's linked from our site. Please do go check it out. He's also written numerous books including the recent kids' book "26 Things That Bug Me: A Special ABC." I want to say thank you to the great team being "The Kojo Nnamdi Show."

  • 13:58:12

    VOGELYou've been listening to "The Kojo Nnamdi Show," which is produced by Brendan Sweeney, Michael Martinez, Ingalisa Schrobsdorff and Tayla Burney with help from Kathy Goldgeier and Elizabeth Weinstein. Engineer today is Andrew Chadwick, and A.C. Valdez is on the phone. Thanks for listening.

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