Perhaps you’ve heard some buzz about periodical cicadas (Magicicada spp.) lately. These insects resemble our typical “dog day” cicadas, which we see in mid-to-late summer in Wisconsin, but they are orange and black with vibrant reddish eyes instead of a dull greenish color. Parts of the US are currently seeing mass emergences of periodical cicadas, which appear by the millions every 13 or 17 years depending on the species. I’ve had a number of questions this last month asking if this was “the year” for us to see them in Wisconsin, but it’s not time for the big show…yet.
Periodical cicadas are sorted into cohorts known as “broods”, which occur in particular geographic areas and emerge at specific points in time. For the most part, these insects are excellent timekeepers and some broods have been documented as far back as the 1600’s in the eastern US. There are entire websites and apps dedicated to these insects and their schedules, and scientists have labelled broods with Roman numerals to help differentiate the cohorts.
With all the broods out there, some parts of the US do see these cohorts overlap in space, but these can be separated by the years in which they emerge. In Wisconsin, the situation is fairly straightforward as we only see a single brood: Brood XIII. Brood XIII’s 17-year cicadas last emerged in 2007, meaning that we’ve got four more years to wait until their mass emergence in 2024.
Interestingly, I’ve received a number of photos and reports of periodical cicadas in Wisconsin over the last month or so. I’ve had several confirmed reports from the Lake Geneva area (Walworth County) a confirmed report from southeastern Dane County, and a suspected report from Sauk County. While most periodical cicadas stick to the schedule, occasionally some of these insects veer off course. These out-of-sync individuals are referred to as “stragglers” and it turns out that Brood XIII has a history of these stragglers. In the late 1960’s, large numbers of stragglers were documented in the Chicago area. Likewise, many of the Chicago suburbs are seeing a similar phenomenon this year. With that said, we did technically see some periodical cicadas this year, but we’ll have to wait a few more years before the real “fireworks”.
“I think I’ve found a kissing bug and wanted to report it” is a surprisingly common line I get at the UW Insect Diagnostic Lab.
I’ve previously written about kissing bugs, but to quickly recap: these are blood-feeding assassin bugs found primarily in South and Central America. Kissing bugs tend to be associated with vertebrate nests outdoors but can bite humans and can also carry Trypanosoma cruzi—a parasite that causes Chagas disease. Due to this concern, I see a spike in website traffic and “reports” of suspected kissing bugs just about any time there’s national news coverage of these insects. While many kissing bug species exist, the vast majority are restricted to tropical and subtropical areas. The northernmost species—the eastern conenose kissing bug (Triatomasanguisuga)—ranges from Latin America as far north as southern Illinois.
Insects don’t care for geopolitical boundaries, but when humans shade in the entire state of Illinois on a distribution map of kissing bugs, it gives the false impression that these insects are on the tollway marching towards Wisconsin’s southern border. However, the eastern conenose kissing bug is rarely spotted in the northern parts of its range and there has never been a verified case of kissing bugs from within Wisconsin.
The regular occurrence of false reports can likely be attributed to hype in the news combined with a good ol’ case of mistaken identity. It turns out that there are a number of common insects that can resemble kissing bugs. One of these, the western conifer seed bug (Leptoglossus occidentalis), is regularly encountered in the upper Midwest because these insects sneak indoors in the fall just like boxelder bugs. Recently, the commonest look-alike I’ve been getting reports of is the masked hunter bug (Reduvius personatus), which can also be encountered indoors.
If you aren’t familiar with masked hunter bugs, there’s a good reason why these insects can sometimes mistaken for kissing bugs—they’re technically kissing cousins. Both kissing bugs and masked hunter bugs belong to the assassin bug family (Family Reduviidae). This is a diverse family of approximately 7,000 species worldwide and we have dozens of common species in the Midwest. The vast majority of these species (including masked hunter bugs) are really beneficial predators of other arthropods and are of little medical importance. In theory, if you picked up and mishandled one of our Midwestern assassin bugs species, it could bite—likely feeling similar to a wasp sting—although that’s about the worst it could do.
Masked hunter bugs are readily identifiable, although the nymphs (juveniles) can have you scratching your head if you haven’t encountered them before. The nymphs are often ¼” – ½” long and camouflage themselves with bits of lint and other debris—as a result, they can resemble miniature walking dust bunnies. Once you recognize this disguise, they’re easy to identify.
Adult masked hunter bugs are slender, roughly ¾” long, and entirely dark coloured. They have long, thin legs & antennae and stout beak-like mouthparts which they use to feed on insects and other arthropod prey. Several key features help distinguish masked hunter bugs from eastern conenose kissing bugs:
Masked hunter bugs are entirely dark while eastern conenose kissing bugs have red on their body
Masked hunter bugs lack the projecting “conenose” present on the head of kissing bugs
Masked hunter bugs have a bulging, “muscular” appearance of their prothorax (trapezoidal region behind the head) when viewed under magnification
Masked hunter bugs have stout beak-like mouthparts while kissing bugs have long, slender mouthparts when viewed under magnification
When it comes to kissing bugs, we simply don’t have these insects in the Upper Midwest, but we do have look-alikes. For side-by-side diagrams showing an eastern conenose kissing bug compared to common look-alikes, visit the ID Guide page on this website: insectlab.russell.wisc.edu/visual-id-guides/
Each year the University of Wisconsin’s Insect Diagnostic Lab receives thousands of arthropod samples and reports from around the state and region, providing a unique perspective into insect and arthropod trends in Wisconsin and beyond. This post is the first half of a series counting down the top arthropod trends in our area last year. The second part will be posted in early February and can be found here.
10) Dagger and Tussock Moths:
A few species of fuzzy caterpillars were surprisingly abundant last year and there’s a good chance you might have bumped into these in your own neighborhood. Two similar-looking yellowish species, the American dagger moth and the white-marked tussock moth, were extremely common around Wisconsin and were two of the most widely reported caterpillars last summer. Another tussock moth associated with milkweed was also surprisingly common in 2018. With many Wisconsinites growing milkweed to attract monarch butterflies, the black and orange caterpillars of the milkweed tussock moth were also noted in abundance around the state last year.
9) Fungus Gnats:
Pick any spot on a Wisconsin map and 2018 was most likely a soggy year. Understandably, rain encourages insects and other creatures that thrive under damp conditions. Last year’s rains created great conditions for fungus gnats, which became quite abundant by late summer. While fungus gnats are harmless to people and pets, they can be an annoyance if present in high numbers. Fungus gnats thrive in damp organic materials, meaning that rich soil, compost piles, and decaying plants can produce masses of these tiny, dark-colored flies. The larvae of these insects can also be common in the soil of houseplants. As Wisconsinites brought their favorite potted plants indoors in autumn to avoid approaching frosts, reports of indoor fungus gnats were common.
8) Purple Carrot Seed Moth:
With several new, non-native insects showing up in Wisconsin every year, the impacts of each species can vary significantly. Some exotics, like the emerald ash borer make massive waves, while others cause merely a ripple. The impacts of one of our newest invasive insects, the purple carrot seed moth (Depressaria depressana), are not yet fully known. This European species was spotted in Wisconsin for the first time last summer and the tiny caterpillars love to feed on the flowers (umbels) of plants from the carrot family. Below-ground plant structures (e.g., the taproots of carrots) aren’t impacted, but notable damage to herbs like dill, fennel, and coriander can occur. As a result, this pest may be a concern for seed producers, commercial herb growers, or home gardeners with a fondness for dill and related herbs. The purple carrot seed moth has been reported in 8 Wisconsin counties thus far [Brown, Columbia, Dodge, Kewaunee, Milwaukee, Racine, Sheboygan and Washington Counties], so new county-level reports are encouraged at the UW Insect Diagnostic Lab.
7) Odorous House Ants
Imagine the stereotypical black ants zeroing in on sugary foods at a picnic and you’d have a fitting profile of the odorous house ant (Tapinomasessile). Of the 100+ ant species in the Midwest, the odorous house ant stood out in spring and early summer last year with its sheer abundance. The UW Insect Diagnostic Lab was flooded with calls about these sugar-loving ants during 2018’s rainy spring, especially when these ants wandered indoors. The spring rains may have forced the ants from waterlogged colonies to seek out higher-and-drier locations, making odorous house ants the most commonly reported ant at the diagnostic lab last spring.
6) Stink Bugs:
While the Midwest is home to over 50 species of stink bugs, one particular species—the invasive brown marmorated stink bug—stands out to give the rest a particularly bad reputation. If you live in a part of the state with the brown marmorated stink bug, you may have already encountered this species. With its habit of sneaking indoors in the fall, this insect replaced boxelder bugs in some areas as the top home-invading nuisance pest of 2018. This Asian species has made the diagnostic lab’s Top 10 list for several years now and unfortunately doesn’t show any signs of slowing down. In 2018 alone, BMSB was detected in 8 new Wisconsin counties, which hints at potential damage to fruit and other crops in those areas in the coming years.
To see the rest of Wisconsin’s top arthropod trends of 2018, check out part 2, available here in early February.
Author’s Note: Original post updated in January, 2019 due to a confirmed report in Waupaca Co. and suspected report in Oneida Co.
One of the most concerning invasive insects to appear in Wisconsin in the last decade is the brown marmorated stink bug (Halyomorpha halys).This Asian species delivers a double-whammy of not only damaging crops and other plants, but also being a significant nuisance when it sneaks into buildings in the fall. Since its initial detection in the state in 2010, populations of this insect have built up slowly but steadily.
What’s the current status of BMSB in Wisconsin?
As of late 2018, 28 counties have confirmed reports of the brown marmorated stink bug and a handful of other countries have suspected sightings.This insect has a strong foothold in the state and was confirmed in eight new counties in 2018 alone—Eau Claire, Jackson, La Crosse, Marquette, Monroe, Richland, Trempealeau, and Waupaca counties.
Two core areas currently stand out for brown marmorated stink bug activity in Wisconsin: the Highway 41 corridor from Fond du Lac up to Green Bay and southern Wisconsin from Dane and Rock Counties east to the Milwaukee metro area.These two areas have the longest history of BMSB in the state and account for the majority of reports thus far.
Much of the state has yet to encounter this insect or truly experience its impacts.When the brown marmorated stink bug is first detected in an area, there’s a proverbial “calm before the storm”. The pattern observed in the state thus far has been a few “quiet” years where low initial populations of this insect result in only a few sightings annually. However, after a few years in a given area, BMSB populations build up to the point where nuisance problems around structures are noted and reports of potential plant damage begin to trickle in.
What’s the Outlook for BMSB?
Unfortunately, Wisconsin has yet to see the full impact of this invasive insect.Observations over the last few years have found that BMSB is able to survive our winters and reproduce in the state, so this adaptable pest will most likely continue to build its numbers in the coming years.
Over time, the brown marmorated stink bug is likely to emerge as one of the top structure-invading pests in the state alongside the likes of boxelder bugs and multicolored Asian lady beetles.In the eastern US, where BMSB has been established for over a decade in spots, problems can be significant. In some cases these malodorous insects have been documented invading homes by the tens of thousands.
While widespread crop damage has not yet been observed in Wisconsin, it may only be a matter of time as population of this insect continue to build in the state.Agricultural problems have also been significant in the eastern US, giving us a glimpse into what could potentially happen in coming years. For example, brown marmorated stink bug caused $37 million dollars in losses to apples in the mid-Atlantic states in 2010 alone.
Having been detected in Portage County in 2017, brown marmorated stink bug may soon start to pose a threat to vegetable production in central Wisconsin.Similarly, specimens confirmed from Door County in 2017 are forcing fruit growers in that part of the state to keep a close watch on their orchards and vineyards.With the recent detection of BMSB in several western Wisconsin counties, we’ll likely see BMSB populations slowly build in that part of the state over the next few years as well.
It was over 170 years ago that Wisconsin was granted statehood. While much has changed over the decades, some things haven’t—like the omnipresence of agriculture. It’s hard not to notice agriculture in Wisconsin, be it crop fields, orchards and vineyards, or our famous dairy farms dotting the landscape. To many, Wisconsin is practically synonymous with dairy, and America’s Dairyland is even enshrined on our license plates. While Wisconsinites may take our dairy prominence for granted, it turns out we weren’t always the Dairy State—at one point in history, you might have even called us the Wheat State.
It’s easy to understand why Wisconsin has a long history of agriculture. The region received an influx of rich soil with the last ice age which allowed us to become a top wheat producer in the early days of statehood. To early farmers in Wisconsin, wheat was a profitable crop in high demand. For a period in the 1800’s, Milwaukee was even the busiest wheat shipping port in the entire world1. Fast forward to today and Wisconsin is best known for its dairy production, while states like Kansas, Nebraska, and the Dakotas are known for their bountiful grains.
It was the mid-to-late 1800’s when the course of Wisconsin’s history was forever altered by a number of factors. Fluctuating wheat prices and overworked soil might have been the primary drivers, but dry weather and a tiny insect also pulled on the reins of history. Just as mosquitoes can thrive after heavy rains, other insects thrive under hot, dry conditions. Droughts of the 1860s, 70s, and 80s set the stage for biblical outbreaks of some of these insects. Farther to the west, fields in the Great Plains fell victim to swarms of Rocky Mountain locusts so massive that they darkened the sky for thousands of square miles.
Closer to home, the pest delivering a coup de grâce to wheat fields was the humble chinch bug, which thrived under the dry conditions at the time. Chinch bugs aren’t much to write home about: at roughly an eighth of an inch long, most folks wouldn’t take the time to examine these tiny, black and white insects. It was by their sheer abundance that these creatures decimated Wisconsin’s wheat fields in the 1800’s. Using needle-like mouthparts, these insects sucked the life out of wheat plants, leaving behind wilted, yellowed stems.
When a pest outbreak occurs in a given year, a farmer might chalk it up to bad luck, bad weather, or other factors and hope things improve the next season. With falling wheat prices and chinch bugs regularly devastating wheat crops in the late 1800’s, Wisconsin wheat farmers realized that their efforts yielded little profit. Without an effective way to prevent the ravages of the chinch bugs, attentions shifted to more fruitful possibilities.
Understanding the biology of the chinch bug was crucial to discovering the limitations of that insect’s destruction. It turns out that chinch bugs are picky eaters with a taste for grasses—wheat, corn, and similar. Unrelated plants, including forage crops like alfalfa, weren’t affected by these insects and could be grown to feed livestock at the very time that the dairy industry was budding in Wisconsin. Decades later our dairy prominence is featured on our license plates.
When enjoying those Wisconsin cheese curds, ice cream, and other dairy treats during national dairy month, chances are you probably wouldn’t have thought about insects—but now you know how the tiny chinch bug helped make dairy a BIG deal in Wisconsin.
1Harbor and Marine Interests. History of Milwaukee City and County Vol I. Ed. W.G. Bruce. 1922. Print.
2J.G. Thompson. The Rise and Decline of the Wheat Growing Industry in Wisconsin. Bulletin of the University of Wisconsin No. 292. Economic and Political Science Series. Volume V(3): 295-544. 1909. Print.
Right around this time of the year in Madison and other college towns across the country, a smorgasbord of furniture and other goods appear along the sidewalk as tenants are frantically moving in and out of apartments. For historical reasons related to the need to register for classes in-person at UW-Madison, many of the leases end and begin in Madison around August 14th-15th each year, leading to an abundance of items on the curb free for the taking. This is such a well-known and easily observable occurrence around Madison, that some have even affectionately referred to it as “Hippie Christmas”.
As the old saying goes, “one man’s trash is another man’s treasure” and this certainly could be the case with free things on the curb. That free couch along the sidewalk might look like the perfect addition to that larger apartment, and it can be hard to beat the price of that curbside armchair. However, there’s the real possibility of unwanted hitchhikers: bed bugs. While I’m all for reducing waste, reusing items, and recycling, the concern about bed bugs should not be overlooked.
Until the mid 1900’s, bed bugs (Cimex lectularius), been a common pest around the world. With the invention of synthetic insecticides around the time of World War II, these insects had nearly been wiped out. Given time, bed bug populations developed resistance to some of those insecticides. The insecticide resistance coupled with the rise of international travel and the bed bug’s stealthy stowaway tactics, meant that it was only a matter of time before they came roaring back onto the stage. That very phenomenon has happened in the past two decades, and bed bugs can now be found in every US state, and in a wide variety of situations––from student apartments to five star hotels. When bed bugs are detected, they can be eliminated with diligent tactics, although the task can be challenging and is best left to pest control professionals. Costs to eliminate bed bugs can easily be $1,000 or more.
Absolutely need to have that nightstand from the curb? A few steps can help prevent issues. The first is to simply know how to look for bed bugs and their telltale signs. Many folks seem to believe that bed bugs are too small to be seen with the naked eye, but this is far from reality. It turns out that adult bed bugs (image above) are roughly the same size, color, and shape as a small apple seed. Juveniles will have the same general shape, but will be smaller. Very tiny whitish eggs (~1mm long) and black spots (from digested blood) on furniture are other classic signs of bed bugs. [A useful guide to identify bed bugs and their signs can be found here].
Before bringing any item in from the curb, examining it thoroughly for any signs of bed bugs is well worth the effort in the long run. Objects with a simple design (ex. a nightstand with few grooves for bed bugs to hide in) are easier to inspect than large upholstered furniture and mattresses. For larger, hard to inspect items, it may not be worth the risk to grab such items. For small items, one easy step is to place them into a large Ziploc bag and put them in the freezer for 7-10 days as a precaution. Bed bugs, or any other insects present in such an item would freeze during that time.
What if you’ve moved into a new apartment and suspect it has bed bugs?Getting a suspected bed bug specimen properly identified is a crucial step. It turns out that there are a number of nearly identical species that can only be told apart under the microscope. These related species are associated with bats and birds; they don’t pose the same headaches as bed bugs and are controlled differently. If you’ve confirmed that bed bugs are present in your apartment, starting a conversation with your landlord is an important step; ignoring the situation is about the worst thing that could be done in such as case. Overall, it’s much easier for a pest control company to come in and eliminate a small bed bug infestation than a large one. This is especially true of large apartment and condo complexes, where bed bugs can spread from unit-to-unit over time, making control much more difficult. In addition, if you happen to be moving out of an apartment that has or might have bed bugs, it’s best to mark any items being discarded with spray paint so that others looking for furniture will know not to bring those items home with them.
For bed bug questions in rental situations and many other tenant-related topics, the Tenant Resource Center of Wisconsin offers assistance. Safe moving and keep an eye out for bed bugs!
What were Wisconsin’s top insect trends of 2015? In this post, we’ll look at the first half of our count-down.
This is the second post in a three part series. The first post of the series (2015’s diagnostic lab statistics) can be found here.
10) Mosquitoes and ticks:
Like most years, Wisconsin had a pretty good mosquito season. Overall, we were close to the average rainfall mark during much of the year, which meant the typical batch of mosquitoes starting after Memorial Day. In many parts of the state, mosquitoes were prevalent throughout June, July, and August. However, this is Wisconsin after all, and mosquitoes seem to be one pillar of summer culture along with beer, cookouts, and fishing. The silver lining of the mosquito story is the fact that West Nile Cases were low for the year, with only four confirmed human cases reported in the state in 2015.
While there wasn’t anything out of the ordinary with the mosquitoes last year, ticks seemed to have a particularly good year in the state. Deer ticks, which can vector Lyme disease can be found essentially statewide. From the standpoint of an emerging health threat, deer tick populations have exploded in the past few decades (our first deer tick wasn’t found in the state until the 1960’s). A recent nation-wide study found that deer ticks were found in nearly half of the counties in the U.S. One of the more alarming trends is urban encroachment. Historically, ticks seemed to be the type of creature you’d pick up if you were out hunting or hiking through the woods. In the recent past, we’ve noticed an increase of ticks found in more urban environments, such as parks and backyards. With roughly 40% of the adult ticks in Wisconsin carrying the microorganism responsible for Lyme Disease, this is an issue that will continue to exist in the state for years to come.
9) “Sucking Insects”
A certain group of insects (the Order Hemiptera) are sometimes known as the “sucking insects” because they possess tube-like mouthparts which are used by many species use to drink fluids from plants. Two of the members of this group, the aphids and the scale insects had a great year in 2015. When these insects feed on plants, a common sign is the presence of sticky, sugary honeydew, which attracts ants and yellowjackets, and can result in the growth of black sooty mold. Aphids and scale insects are common and typically present in low numbers, but the conditions must have been just right for their populations to thrive in 2015. As a result, there were many reports throughout the state of honeydew “raining” down from trees and shrubs onto vehicles, decks, outdoor furniture, and people below. If you felt “rain” on a sunny day last summer, the actual cause may have been honeydew dripping down from aphids or scales in the trees above!
8) Long Lost Pests: Japanese Beetle and Gypsy Moth
Two of our best-known landscape pests, the Japanese Beetle and the Gypsy Moth had been very quiet in 2014, but resurfaced last year. Japanese beetles had been low across the state in 2014, likely due to the brutal winter of 2013-14 killing many of the soil-dwelling grubs. While we did see an increase in beetle activity in 2015 compared to 2014, their numbers still seemed low compared to the long term average. However, with a milder el Niño winter, it’s possible that we could see increased winter survival and higher Japanese beetle populations in 2016.
Gypsy Moth populations have been low the past few years in Wisconsin. Damp spring conditions can result in a fungal disease killing many of the caterpillars, which likely helped lessen populations in the recent past. It’s also not unusual for some long-term cyclic patterns to be involved with insect populations. For a number of potential reasons, Gypsy Moth populations seemed to rebound a bit in 2015, and many reports of sightings and damage came in to the diagnostic lab, particularly from the south central portion of the state (Dane, Rock, Walworth Counties). Because Gypsy Moth can be a destructive defoliator of hardwood trees, it’ll be good to keep an eye out for this one in 2016 to see if the populations continue to climb.
7) Emerald Ash Borer
This is our most destructive forest pest in the state, and unfortunately, there doesn’t seem to be anything capable of completely stopping this pest. While we didn’t see many additional counties added to the quarantine map in 2015, there were many municipalities that detected EAB for the first time. At the moment, 39 of the 72 Wisconsin counties are quarantined for EAB and this number will continue to increase over time. Like Dutch Elm Disease in the past, Emerald Ash Borer is changing and will continue to change the appearance of our urban forests and woodlands for years to come.
6) Spotted Wing Drosophila
This invasive pest first showed up in the state in 2010, and became a significant fruit pest almost immediately. Since its introduction, SWD has spread widely and can be found in most counties in Wisconsin. Very similar to 2014, SWD was detected in dozens of counties across the state. SWD can attack a wide variety of fruit, but due to the fact that this insect doesn’t seem to become active until July, the late-season raspberry and blackberry crops are hit the hardest. Luckily Wisconsin’s famous cranberry crop does not seem to be favored by this invasive pest.
“Kissing” and “bugs”—two words you wouldn’t expect to be put together in the same sentence have been strung together rather frequently in the news lately. No, this isn’t some poorly understood internet phenomenon amongst the youth of the country. Rather, when you hear about “kissing bugs”, we’re really talking about a group of blood-feeding assassin bugs (Family Reduviidae, Triatoma species).
So what’s the story behind these insects and why the hype?
Kissing bugs are similar to bed bugs as they both feed on the blood of vertebrate hosts. However, unlike bed bugs which have anthropophilic habits, kissing bugs are typically associated with animal nests in wooded areas. Kissing bugs don’t go out of their way to sneak indoors, although if they do happen to wander in they can be attracted to the heat and carbon dioxide of a sleeping human. When human bites do occur, it can often be on the exposed, softer skin of the face, hence the nickname of “kissing bugs”. The biggest concern with kissing bugs is that under the right conditions they can serve as a vector of American trypanosomiasis (aka Chagas Disease), a serious disease that can lurk in the body and ultimately affect the heart and other organs.
What does the kissing bug story have to do with Wisconsin and the Great Lakes region?
In brief: not a whole lot. While there are nearly a dozen species of kissing bugs in the western hemisphere, these insects are primarily found in rural Central and South America. I recently spent some time amongst the Wisconsin Insect Research Collection’s 8 million+ specimens, and found no verified cases of kissing bugs in Wisconsin. Technically, these insects have been found in some of the southern states, although they tend to be quite rare in the US and there isn’t any evidence to suggest that they’re expanding their range or increasing their numbers. Unless you’ll be spending an extended amount of time in Central or South America, the threat posed by kissing bugs and Chagas disease is basically non-existent. Overall, the hype about kissing bugs is more bark than. . .bite.
Think you’ve found a kissing bug in Wisconsin (or elsewhere)?
There are a few look-alikes that could potentially be confused with kissing bugs. Boxelder bugs (Boisea trivittata) share the red and blackish coloration of certain kissing bugs, while the masked hunter assassin bug (Reduvius personatus) shares a similar body size and shape. However, due to the slender body and similar “checkerboard-like” pattern around the abdomen , the insect getting confused the most with kissing bugs at the moment seems to be the western conifer seed bug (Leptoglossus occidentalis), which can be very common in Wisconsin and in many parts of the country.
Why the western conifer seed bug? As described in an earlier post, western conifer seed bugs frequently try to sneak indoors in the fall to seek out a sheltered spot to spend the winter. As a result, encounters with these harmless insects occur on a regular basis. Want some peace of mind that the insect you’ve seen is a western conifer seed bug and not a kissing bug? Check out this handy side-by-side guide comparing the eastern conenose kissing bug (Triatoma sanguisuga) with the western conifer seed bug:
Further reading: Gwen Pearson recently covered the Kissing Bug story for Wired and included some excellent references.
Since last week’s press release on the Brown Marmorated Stink Bug by the Wisconsin Department of Agriculture, Trade and Consumer Protection (DATCP) and my own blog post on this invasive pest, I’ve been getting many reports of this insect from Wisconsin residents. It’s always great to get reports from the community as it helps us keep track of this invasive pest.
Interestingly, there have also been many cases of an insect that somewhat resembles BMSB: the Western Conifer Seed Bug. Both insects try sneaking into buildings to look for shelter and possess “checkerboard” patterns at the back of the body. However, when you have the insects side by side, they can be easily separated. The western conifer seed bug is longer and more slender in appearance, has dull reddish and orange patches on the body, and has distinctly dilated hind legs (think “bell-bottoms”). In addition, these insects possess a unique zig-zag (“lightning bolt”) pattern on each wing, which can easily be seen with the naked eye as illustrated in the ID guide below.
While the western conifer seed bug can sneak into buildings in the fall, they tend to invade in relatively low numbers. This species feeds on the seed cones of pines and other conifers, but doesn’t seem to cause much (if any) harm to the trees. Overall, they can be a bit of a nuisance, but that’s about it, unlike BMSB, which can potentially damage many different types of plants.
Have western conifer seed bugs around the house and want to know more about their biology and management? Check out this handy factsheet from UW-Extension.
Every fall, residents throughout Wisconsin and many other parts of the country face an invasion by a number of insects: boxelder bugs, multicolored Asian lady beetles, western conifer seed bugs and cluster flies, to name a few. With the coming frosts, these insects are simply trying to find a sheltered location to settle for the winter. Out in nature, many of these insects would simply crawl into a rock pile or beneath the loose bark of a dead tree to overwinter.
But why rough it out in nature if there are perfectly good buildings to sneak in to? Next time you’re cleaning the gutters, take a moment to peek around the outside of your house. Small gaps in siding, soffit areas, around door and window frames, and cracks in the foundation are all potential spots for insects to sneak through. And if they make it through? Well, you could be in for some extended visitors. . .
In addition to the usual fall invaders, a relative newcomer starting to pop up in Wisconsin and other parts of the Midwest is the invasive Brown Marmorated Stink Bug (Halyomorpha halys). Like the boxelder bugs and multicolored Asian lady beetles, brown marmorated stink bugs (BMSB) like to find their way indoors for the winter. This Asian species was first detected in Wisconsin back in 2010 and for reasons we don’t fully understand, their numbers have been quite low the past few years. As of late 2014, BMSB has been confirmed or suspected in 10 Wisconsin counties, with most of the reports coming out of the Madison and Milwaukee area. A handful of sightings each year has been the pattern.
Unfortunately, we may be at the beginning of a shift in BMSB populations in the state. In early 2015, there were at least 6 specimens found in Wisconsin by early March. Despite the quiet summer, the sightings have started popping up again in late September and October of this year. What’s more concerning is that we’re starting to see groups of these insects clustered together (previous sightings had consisted almost exclusively of lone individuals).
Not only are these unwanted houseguests a nuisance, but quite frankly, they smell bad. True to their title of “stink bug”, brown marmorated stink bugs possess glands that can emit a pungent odor. Some consider the odor to be coriander-like, while others say it resembles musty gym socks. Invasive species [check]. Nuisance invader [check]. Smells bad [check]. That’s all, right? Unfortunately, not quite. Just like a bad late-night infomercial: Wait! There’s more!
It turns out that brown marmorated stink bug has the potential to be quite a nasty plant pest and rivals the Japanese beetle in the breadth of its palate. Brown marmorated stink bug seems to feed on just about anything under the sun: field crops like corn and soybeans, vegetables like tomatoes and peppers, and even ornamental trees and shrubs. Fruits like apples and grapes can be hit especially hard. In some cases, the mere presence of BMSB can be a problem: imagine being a vintner and having your batch of wine tainted by the presence of a few squished stink bugs! In the eastern U.S. there are regular reports of agricultural problems and growers have to spray to control these insects. We haven’t had any reports of plant damage in Wisconsin yet, but that could change over time if BMSB populations continue to climb.
So what can you do about brown marmorated stink bugs? For starters, learning to tell them apart from our native stink bugs is relatively easy. Look for the alternating “checkerboard” pattern along the back edge of these half-inch long insects and the two light bands on the otherwise brown antennae.
With relatively few sightings in Wisconsin at this point, we’re still trying to get a feel for where this insect is. If you suspect that there may be brown marmorated stink bugs around your house, take a picture of the insect and email it to me at (firstname.lastname@example.org) for identification. Another option is to collect a physical sample and mail them in to the Insect Diagnostic Lab for identification (instructions on how to submit samples can be found here).
If brown marmorated stink bugs or other fall invading insects are trying to get into your house, one of the best things to do is to inspect the outside of your home and physically seal up cracks and crevices where they’re trying to sneak in. Once fall invaders are indoors, hauling out the hose attachment on the vacuum cleaner is often one of the best steps to remove them.