MR. KOJO NNAMDIYou wouldn't know it this week, but summer is coming and there may be a silver lining to the polar vortex that brought us freezing cold and lots of snow this winter. There may be fewer bugs around this season. The cold temperatures may have killed off some of the pests which hail from warmer, southern climes, including a fairly new arrival in our area, the stink bug. But that doesn't apply to all six-legged invaders, like mosquitoes or ticks.

MR. KOJO NNAMDIJoining us to discuss what you can expect for your picnics and backyard cookouts this summer, Mike Raupp, the bug guy. He is a professor of etymology at the University of Maryland, who it is always a pleasure to welcome to these airwaves, even though we're in a new location since you were here the last time, Mike.

PROF. MICHAEL RAUPPThese are fantastic digs, Kojo. I love this here. The sun is shining, but it's a little chilly out there today.

NNAMDIIt is a little chilly out there. Hopefully you'll like the digs enough to come back fairly often. If you have questions or comments for Mike Raupp, give us a call, 800-433-8850. Anything you want to know about bugs? Are you hoping for a less buggy summer this year? You can send us an email to kojo@wamu.org. Mike, so the frigid, snowy weather we suffered through this year might actually mean good news when it comes to stink bugs in particular. What happens to them in very cold weather?

RAUPPWell, it depends on well the fattened up in the autumn. In other words, it depends how much meat they put on during the growing season, if they found a very good place to hunker down that's well protected, they're just going to do fine. I can tell you, Kojo, the ones up in my attic must have had a very good meal before they packed it into my attic because they've been wandering around my console in the evening time for the past couple of weeks.

RAUPPHowever, in other places, one of my colleagues over at Virginia Tech found that in his location, which got down into negative numbers, about negative five up in Blacksburg, Va., he saw as much as 95 percent mortality in the stink bugs that were over-wintering there. So what we're doing now is we're trying to establish a baseline to find out if this is way out of the ballpark, or if this is the kind of kill rate we might expect to see when we have these chilly temperatures.

RAUPPUnfortunately, some of the other results that are coming in now suggest that that kill rate might only have been in the ballpark of about 50 percent. So we're going to wait and see, but we're going to be cautiously optimistic that in some locations, if those stink bugs were not clever and if they went into winter skinny, that the polar vortex is going to put the beat down on those guys.

NNAMDIAnd now they're coming out because it's getting a bit warmer during the days?

RAUPPYeah, exactly. The ones that have come indoors, your attics are now getting warmer as we have the increased day length and the better sun angle. So your attic and the places where they've hunkered down inside your home are warming up. They think it's spring. They think the leaves are about to burst out on the trees and they'll blossom in fruit. They're a little bit premature in their optimism here, but that doesn't stop them from emerging, breaking their over-wintering torpor and beginning to move down into your study or on your picture window in the morning.

NNAMDIYou say this is a break their diapause?

RAUPPYes.

NNAMDIWhat's their diapause?

RAUPPSorry. It's a term we use with bugs. It basically is very much akin to hibernation. For insects that live in temperate climates, they must endure this inimicable season, when the leaves are gone from the trees, when it's simply too cold to survive outside. And to do this, they will find protected locations. They will create antifreeze in their blood so they simply do not freeze. And then they will reduce their metabolism, hunker down, chill out for four or five months until the warm weather returns. And that's the signal for their physiology to resume, for them to get up and get going and go out into the treetops and feed again.

NNAMDIBecause this is something people know about reptiles, but perhaps not about insects, they are cold-blooded. And so during the winter time what does that mean for them?

RAUPPWell, they basically are going to be whatever temperature the ambient is outdoors. Remember, now, 60 million years ago when these guys evolved there weren't a lot of nice houses and tool-sheds for them to over-winter in. What they had to do was find loose bark on trees, perhaps a rocky outcropping at a mountaintop. Climb in there, get away from their predators, chill out for several months. And then when Mother Nature warmed the Earth again, it was time to get out and get busy.

NNAMDIWe're talking with Mike Raupp. He is a professor of etymology at the University of Maryland. He's also known as the bug guy. If you have questions or comments for Mike, give us a call, 800-433-8850. Do you have a stink bug problem where you are? Many of us find stink bugs to be an annoyance in our houses, but they're more than that. What do they do to crops?

RAUPPYeah, the real punishment comes for our fruit growers, our orchardists, folks that are growing apples, peaches, pears, cherry. Back in 2010 when we had the first major outbreak here in the Mid-Atlantic region, our apple growers lost more than $37 million to stink bugs. So in addition to our fruit growers, folks that are trying to grow organic vegetables, organic peppers and tomatoes, these are two of the favorite foods of those nefarious stink bugs.

RAUPPAnd they can cause extreme damage. And for organic growers there are very little tools that we have to help them control those stink bugs. And for our homeowners, home vegetable gardeners, they can be a major problem.

NNAMDIIt's my understanding that this is the first winter that has tested the survival of these bugs. Stink bugs are relatively recent arrivals in our area. What is the species that we have here and where the heck are they from?

RAUPPYeah, this is Halyomorpha halys. And these are originally from Asia. They're very common in China, Korea, Japan. They first showed up in Allentown, Pa., of all places. Probably came in with a shipment of goods, perhaps through the Port of Elizabeth, in New Jersey. Would up on a semi. Somebody opened a warehouse in Allentown and out they popped. So they've been here from the middle or perhaps early 1990.

NNAMDIOnto Mike, who hails from Blacksburg, Va. Mike, you're on the air. Go ahead, please.

MIKEHi, I'm down here in Blacksburg, at Virginia Tech. And you were saying about -- talking about the high mortality rate. I have to live in an attic in the house I live in and it's just covered in stink bugs. And I was wondering -- I get a lot near my window. And I wonder if they're coming in from the outside or if they're all already somewhere inside my attic.

RAUPPHey, Mike, great question. And thanks for the call. Poor you. I think what you've got to do is open up that attic, Mike, bash out the walls, let some of that chilly air and freeze those babies out. Get out of town for a couple days and open that up, let them freeze. I'm kidding of course. They did come in in the autumn. In the autumn, as the days grow short and the temperatures chill, the stink bugs will seek refuge.

RAUPPSo the little tenants you find up in the attic -- and if you have a lot, I'd charge them a penny a piece. If you've got a million, you're going to come out ahead on that rental now. They're just going to hang out in the winter time, but they did come in in autumn. They are not moving into your house now. Because it's getting warmer in the attic, they're becoming active. And that's why you're seeing them move about.

NNAMDIMike, thank you very much for you call. Good luck to you. You, too, can call us, 800-433-8850. But stink bugs are southern pests. What are we seeing in terms of bugs normally in warmer southern areas coming north?

RAUPPYeah, we've had an increase influx of several different southern species over the years. One of the most common ones we have is called the harlequin bug. This one came out of Mexico. With our warmer winters this has been able to make inroads as far north as Maryland and even further north. And this one really likes our collards. This is after our cold crops. One of my favorite are greens. It'll get on cabbage. It'll get on radishes and it really rips them up.

RAUPPThe good news in this one, Kojo, is we know once those temperatures drop to the middle teens, as they did, once it gets below 20 down to 15, 14, 10, we're going to see very high mortality in those harlequin bugs and we expect them to be suffering a polar punishment here due to the vortex. We expect lower numbers.

NNAMDIWhat has this winter meant for other bugs around the region and around the country, especially for some of the more destructive pests?

RAUPPGood news for the folks living out West in places like Wisconsin and Minnesota. They've been exposed to the emerald ash borer which we also have here in Maryland. This particular wood-boring beetle has killed tens of millions of ash trees nationwide. And we know that when temperatures drop to about negative 20 to negative 25 that beetle, which is under the bark of the tree, is going to suffer very high levels of mortality.

RAUPPAnd indeed they have. So there's going to be a break in the Midwest where the emerald ash borer is resident. Also, up and down the Appalachian chain there's been a very bad performer called the hemlock woolly adelgid, that was first introduced in the 1950s in this region. It has since spread both north, south and west and has killed tens of thousands of hemlock trees in the Appalachian range, in the Shenandoah.

RAUPPAnd these are critical habitats. These are watershed regions. You can hike now in several places in the Blue Ridge and hike through a ghost forest that was at one time a magnificent forest of hemlocks. The good news here, in several locations up and down the Appalachians the temperatures dropped well below zero. And once temperatures hit about a minus seven to minus ten Fahrenheit, that's going to levy a heavy toll on these hemlock woolly adelgids.

RAUPPAnd in places where it dropped to minus 15 or 20, we might expect to see those things actually extirpated. So this is going to bring some very good relief to our poor beleaguered hemlock trees throughout the Appalachians.

NNAMDIIt hasn't been a good winter for gypsy moths either, has it?

RAUPPIn these cold locations, once those temperatures dip down into the negative teens and approach minus 20, it's going to put the beat down on the gypsy moth egg masses, as well. So there is a bright side to this polar vortex. My fuel bill isn't feeling it, but some of the trees and some of the bugs will certainly take it on the chin.

NNAMDIHere's Jason in Burke, VA. Jason, you're on the air, go ahead please.

JASONHey, Kojo. I was wondering if your guest would be able to comment on is this selection pressure, this really cold winter enough to -- may potentially breed a more resistant strain of these stinkbugs and caterpillars and things like that?

NNAMDIDo they adapt?

RAUPPYeah. You bring up an excellent point. This is Mother Nature's safety plan, isn't it, Jason? That basically there's variation in any population. I think this could be part of the reason behind the variation we saw in the stinkbug mortality. I'm looking at Kojo here, he's about six foot and a really handsome guy, I look more like a hobbit. It's just part of nature's plan that there's variation in any population, you're absolutely right.

RAUPPExposure to cold temperatures or warm temperatures for that matter will select, help select individuals that are better adapted for those environments. The good news here is that some southern pests like the harlequin bug, the cottony cushion scale, the Florida wax scale that have penetrated our region where we've been very mild for many, many years. They simply don't have time to adapt. And they are really going to get a beat down, I think.

NNAMDIJason, thank you so much for your call. We've got to take a short break. If you have called, stay on the line. We'll be returning to our conversation with Mike Raupp. If you're thinking about calling, then the number is 800-433-8850. Do you have questions for Bug Guy Mike Raupp? Are you a gardener? What pests do you deal with? 800-433-8850 or you can send email to kojo@wamu.org. You can shoot us a tweet @kojoshow. I'm Kojo Nnamdi.

NNAMDIWelcome back to our conversation with Mike Raupp. He's a professor of entomology at the University of Maryland. He's also known as the Bug Guy. Mike, we got an email from Michael in Falls Church, VA, "My attic is about three months ahead as far as warmth and comfort for box elder bugs. Would bombing the attic with bug killer help get rid of them? They are dumb, so stupid and walk around seemingly with a sign saying, please kill me."

RAUPPWell, Michael, I think you should let them have their way then. You can do these in, why not? But I think rather than bomb, what I guess I would recommend in this case is if you can lay hands on a Shop Vac, I think I'd rather see you -- if this is an attic and if this is a space that you use often, I'd recommend that you get a Shop Vac and you simply go up there with that Shop Vac, vacuum those little rascals up and then take them outside and you can treat them with extreme prejudice in whichever way you see most pleasant.

NNAMDIHow about garden pests that we might see around here? What has the winter meant for them and the plants that they feed on?

RAUPPWell, we're going to see a dent in some of our things. Things like the corned earworm are sensitive to these cold temperatures. They spend the winter as a pupa down in the soil. And when soil temperatures get very chilly and if you turn your soil, you will expose those pupa to the chilly temperatures and this will put a death in those guys. For our corn growers, also things like sap beetles are important. We expect their numbers to be lower during this kind of year.

RAUPPBut, unfortunately, pests such as our Japanese beetle tend to move only deeper in the soil. And I'm guessing that Japanese beetles are likely to escape the polar vortex because they simply are too deep. So some will take it on the chin, others I think are, unfortunately, going to be just fine.

NNAMDIThere are also good bugs for gardeners. Which insects are welcomed?

RAUPPOh, well, you know, now you've got me going. These are some of my favorites. Ladybird beetles, of course, are very high on my...

NNAMDIIt's my number one favorite, yes.

RAUPPNumber one favorite. Lacewings, these are maniacal predators, the juvenile stages have large saber-like jaws that they grab aphids with and exsanguinate them. They suck their blood out in 90 seconds they'll get another one. There are many parasitic wasps that are highly beneficial. In fact, last week, we had a warm evening and we saw our first parasitic wasps. These are called ichneumon wasps.

RAUPPThey are parasites of things like cutworms in my flower garden. So it's good to see that they've survived the winter in good order.

NNAMDIOn to the telephones again. Here is Joyce in Leonardtown, MD. Joyce, your turn.

JOYCEHi. I want to ask if there's anything we can do about chiggers. They seem to be attracted to me and they leave a serious bite that I suffer with for most of the summer and usually it scars. We've tried spraying and I don't really like to do that. But I don't know what to do besides stay inside all summer. And I wonder if there's an antidote. It's been suggested that we grow a certain, like a crawfish and holes around the property.

JOYCEBut we don't really have a place to do that. And that might be an old farmer's tale anyway. So do you have any suggestions? And is there an antidote to the bite? Nothing that I have heard just over-the-counter seems to work. And when I do go outside, I have to cover up so much that it's not pleasant. So, (unintelligible).

NNAMDIOkay. Here's Mike Raupp.

RAUPPJoyce, these are all good questions. And they only go after very pleasant and attractive people. So, unfortunately, you bear that burden. What I'd suggest is, number one, stick to the trails. You're going to pick up your chiggers in the ecotone, the places where the grasses are high. This is where the small mammals live, the small mammals and birds on which the chiggers normally feed. We're kind of incidental hosts.

RAUPPYou're doing the correct thing in terms of covering up. Try to wear long pants. You can actually buy a repellant or tick and chigger resistant and repellant clothing. You might give this a try when you walk about. When I'm in chigger territory, the first thing I do when I get back indoors is to hop in the shower and wash off my legs, any kind of exposed skin. This will help dislodge some of these tiny mites, which are what chiggers are and prevent them from boring into your skin.

RAUPPSo this is your best bet is actually prevention. The crayfish, I don't think that's a good idea because they've got nothing to do with chiggers. It's the small mammals, the grassy areas where these things breed. Try to keep them off. And when you get indoors, try to remove them. And if you do get chigger bites, don't do things -- another remedy is to put nail polish over the bite. The chigger is actually off of you before you feel that bite.

RAUPPWhat you're reacting to is a protein that the chigger leaves behind after it feeds. So you're not going to kill those chiggers once you start to feel the bite. Your body is simply reacting. So things like antihistamines, analgesics will help. But antihistamines in particular with the itching and irritation. So, unfortunately, that's your best bet.

NNAMDIJoyce, good luck. Go ahead please.

RAUPPYes, please.

JOYCEThank you so much, all right.

RAUPPYes.

NNAMDIGood luck to you and thank you so much for your call. I want to talk about mosquitoes in general, but one mosquito in particular because there's a somewhat worrisome mosquito-borne virus that's sweeping the Caribbean. Public health officials are concerned that it could spread to the U.S. Presumably, the worry is that mosquitoes travel from their native regions and along with disease. Talk a little bit about the chickungunya.

RAUPPThe chikungunya, not a good performer. This is what we call an arbovirus. I believe this one is carried by the yellow fever mosquito, Aedes aegypti, which again is one of the most important and serious vectors of these viruses known in the world. Now the chikungunya virus is one that will give you nausea, fevers, headaches, rashes. The real problem here will also cause joint pain and inflammation that may be rather long-lasting.

RAUPPAnd you're going to feel terrible. It's not all that severe in terms of cases of the fatalities. But I've read that you will wish you were dead if you get the chikungunya. Now it's moved into the West Indies. It's one several islands. The problem here, Kojo, is that the Aedes aegypti, the yellow fever mosquito is endemic in Florida and throughout our Gulf states. So the issue, as I see it, is people that may be traveling to some of these outer islands for vacations, school kids, college students for spring break, if they become infected with this virus, they can bring it back to the United States.

RAUPPAnd here we have the vectors and now we have the potential of bringing back a virus that can establish itself along the Gulf Coast and create many kinds of problems. So this is not good news.

NNAMDIHow many types of mosquitoes are we dealing with in this region and is that number growing?

RAUPPThat's a great question. The big introduction, we have hundreds of mosquitoes up and down the East Coast. And Maryland is a rich place for many, many kinds of mosquitoes. I think many people don't realize that in the 1800s, malaria was right here in Washington, D.C. So we have competent for many kinds. I think the big impact really came back in the '80s with the introduction of the dreaded Asian tiger mosquito.

RAUPPBecause prior to that, mosquitoes were basically dawn and dusk biters. Maybe they bit dust too, dusk biters. But now we've got a mosquito that bites all day long. This one came in through the Gulf states and it simple spread up the coast. But, again, this is part of a global change. As the world warms, these southern species again are able to penetrate further north and this winter has indeed done that.

RAUPPSo it's not with global trade, with the increase commerce. The Asian tiger came in with a shipment of tires to be recycled. They were filled with water, the larvae came in and, hence, it was introduced. So I think with global trade we can expect to see new arrivals of all kind to this country.

NNAMDIWell, globalization brought some of these pesky pests, just leave and go someplace else.

RAUPPAbsolutely. We've given the worst insect pest to Asia. China now has a species called the white moth, which we know here as fall webworm. It's become the number one forest pest in China.

NNAMDISomehow I take no comfort in that whatsoever. Do we know how mosquitoes have faired during this winter's harsh temperatures and can we hope for less swatting at this summer's cookouts?

RAUPPYeah. Well, the good news here on this, they have very, very clever adaptations for withstanding cold, unfortunately. We have mosquitoes that do very well in places like Greenland, which is much colder than here. Some of the 80 species. They, over winter, primarily as eggs. Some of the ones that spread west Nile will over winter as adults. But I don't really see that we're going -- we shouldn't expect a dent in those indigenous mosquitoes, I don't believe.

RAUPPThey've seen this kind of cold in their history. So, unfortunately, I think not. As cold persists, however, it causes the mosquitoes to have a later start. So, again, their development is based on temperature. So the longer we stay chilly, the further back in the season they will be pushed and there will simply perhaps be less time for them to complete more generations.

NNAMDIWe have Len (sp?) in Silver Spring, MD. Hi, Len.

LENHi, Kojo. Great show. We missed you when we lived in Florida for three years.

NNAMDIWell, glad to have you back.

LENI have a question on these electronic plug-ins that say they keep the bugs out of your house. The house-sitter who was in our house for two years, plugged them into all the outlets. Do you know anything about that? Does it work? Or is it just psychologically working?

RAUPPWell, what do you think, Len? Do you have less bugs now than you had before?

LENIt's winter, so I don't know.

RAUPPOkay. Well, you know, I get asked this question from time to time. I simply can't find a well-documented scientific study to support this. So that's why I asked. I was about to say, if you think they've worked for you, then that's good. And I certainly wouldn't dissuade you from doing so. But I cannot find a scientific report to back this up. So I'm just going to kind of leave it at that. I personally would not do this in my own home.

NNAMDILen, thank you so much for your call. Another worrisome and disease-carrying insect is the tick, which can carry illnesses like Lyme disease. Do we know what this cold winter has meant for ticks?

RAUPPAgain, ticks have been out an awfully long time, Kojo. They've been at it for tens of millions of years. They've seen warm. They've seen cold. I think the ticks are going to be okay. The good news here, however, is that the -- one of the hosts, the white-footed mouse, the small mammals from which these ticks often take their first meal and often pick up the, really, the bacterium that's the causal agent of Lyme disease, we know that severe winters will suppress the populations of these small mammals.

RAUPPSo what we might expect, we wouldn't necessarily expect to see a decline in the tick populations this years, but perhaps next year downstream if the mice populations have been impacted throughout their range by these cold temperatures and there are fewer mice for these larval ticks to feed on, this means fewer of these ticks will survive, fewer of these ticks will pick up the Lyme disease causal agent.

RAUPPAnd perhaps two years downstream, we might see a dip in the incidence of Lyme disease, which would be a very good day.

NNAMDIOn to Kim in Eldersburg, MD. Kim, you're on the air, go ahead please.

KIMHello. I have to say I have immensely enjoyed this discussion, you're quite witty. My question for you is, is there any hope of some kind of defense against the stinkbugs? They seem to have just been able to run rampant without any kind of, you know, predators or anything. And we don't have any traps or any kind of defense. I'm just wondering if there's any hope in the horizon even?

NNAMDIHere's Mike Raupp.

RAUPPYeah, Kim, there is hope on the horizon actually. We've learned a great deal over the past two years. There's a large team of scientists nationwide working on this project. For our commercial growers, we found some very clever ways, better ways to time treatments to help smack these bad boys down. For the homeowners, folks like yourself, we now know that in our landscapes, in our nurseries in particular, some of the native natural enemies, tiny parasitic wasps that formerly were attacking other stinkbugs that are native to this country have now jumped over and they're beginning to have an impact on our stinkbugs.

RAUPPThere's a whole host of predatory insects, crazy guys like the amazing wheel bug. It's an assassin bug. It loves to eat stinkbugs. Spiders are eating stinkbugs. So we're seeing a whole host of natural enemies now attacking and killing stinkbugs. And I think we can be optimistic that some of the good guys in this country are going to put the beat down on this exotic pest.

NNAMDIMike Raupp is the Bug Guy. He's a professor of entomology at the University of Maryland. Mike Raupp, always a pleasure.

RAUPPGreat to be here, Kojo. You caught me sipping on my water. Thank you so much, sir.

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