Category Archives: Bugs

Is This a Kissing Bug?

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:

Is this a kissing bug?
Distinguishing features of the Eastern Conenose Kissing Bug and Western Conifer Seed Bug; click for larger version. Photo Credit: PJ Liesch, UW-Entomology

Further reading:
Gwen Pearson recently covered the Kissing Bug story for Wired and included some excellent references.

Conifer Seed Bugs

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.

Brown Marmorated Stink Bug ID
Identifying features of the Brown Marmorated Stink Bug; click for larger version. Photo Credit: PJ Liesch, UW-Entomology

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.

Western Conifer Seed Bug-ID Guide_opt
Distinguishing features of the Brown Marmorated Stink Bug and Western Conifer Seed Bug; click for larger version. Photo Credit: PJ Liesch, UW-Entomology

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.

Why Such a Stink About a Bug?

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.

MALB Overwintering_opt
Multicolored Asian Lady Beetles often spend the winter in sheltered spots, such as beneath the bark of dead trees. However, they can just as easily sneak into buildings. Photo Credit: PJ Liesch, UW-Entomology

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!

Bad Bug Checklist-Upload

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 shrubsFruits 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.

Brown Marmorated Stink Bug ID
Identifying features of the Brown Marmorated Stink Bug; click for larger version. Photo Credit: PJ Liesch, UW-Entomology

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 (pliesch@wisc.edu) 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.

 

Wisconsin’s Top 10 Insect Stories of 2014 (Part I)

The year-end stats are in: a grand total of 2,092 insects, mites, spiders and other curiosities were submitted to the Insect Diagnostic Lab in 2014. With the ubiquity of smart phones and internet access, nearly 60% of the cases handled in the lab this year consisted either solely of digital images or as digital images accompanying a physical specimen. While the vast majority of cases came from within Wisconsin, there were occasional images and questions sent in from other states and even other countries (including Mexico, England, Ireland, South Africa, India, Guatemala, the Philippines, Spain, Portugal, Afghanistan, and Jamaica).

When it comes to the insects in Wisconsin this past year, several stories pop out. First of all, several of our “usual” pests were noticeably down this year: gypsy moth, Japanese beetle, and box elder bugs, to name a few. In contrast, the emerald ash borer had quite a year and was detected in many new locations, leading to over a dozen counties being added to the quarantined zone in the state. Then there were some cases that seemed to appear overnight: the spring mosquitoes and the massive mayfly hatch in late July.

Below you’ll find the first part of a three part series describing the Top 10 insect-related stories of 2014 from Wisconsin. Parts two and three will be released over the next two weeks.


10) Mosquitoes: Our unofficial “state bird” made news headlines across the state starting Memorial Day weekend. In some spots, the mosquitoes were so bad, that outfitters of recreational canoeing trips were turning customers away, lest they fall victim to the winged vampires.

What caused the mosquito problems in 2014? It boils down to some ideal conditions, as far as the mosquitoes are concerned. With over 50 species of mosquitoes in the state, each species has its own unique habits. Some rely on the moisture from melting snow to develop. Others wait for rain to flood depressions in the woods, where female mosquitoes had laid their eggs. Some other species rely on more permanent bodies of water, such as drainage ditches and rain-filled containers. With the late snowmelt and the heavy rains this spring and summer, our mosquitoes had plenty of moisture to use.

If there’s a silver lining of the 2014 mosquito season, it’s that the number of West Nile cases were down in the state. It turns out that our heavy rains created temporary pools out in the woods, which are favored by our “floodwater” mosquitoes. For the most part, these species are a nuisance, but don’t carry diseases like West Nile. The mosquitoes that spread West Nile tend to prefer more permanent bodies of water.  When you have lots of rain, it can sometimes cause these more permanent bodies of water to overflow, flushing the mosquitoes away. It may be counterintuitive, but our worst West Nile year of the past decade was actually the droughty year of 2012.

9) Invasive Leaf Beetles: Two different species of invasive leaf beetles (Family Chrysomelidae) were detected in Wisconsin this past year: the lily leaf beetle and the viburnum leaf beetle. Both of these beetles have unusually similar histories: they’re both known from Europe but were found in Canada in the mid-1940’s. Both made their way into New England in the 1990’s and have been popping up in other locations since then.

The lily leaf beetle was detected for the first time in Wisconsin in July in the Wausau area. This species feeds on true lilies in the landscape and has been found at a handful of sites in Marathon and Wood counties. The viburnum leaf beetle had technically been found once before in the state a few years ago in Dane county. At the time it had been found on a recently planted viburnum bush, which was removed and the insects were eradicated. Technically, the case that popped up in the Milwaukee area in late summer on an established viburnum bush is our second record in the state. Unfortunately, the original source of the insects and extent of the current infestation are not fully understood at this point.

Lily Leaf Beetle (Lilioceris lilii)
Lily Leaf Beetle (Lilioceris lilii); Photo Credit PJ Liesch

While these two beetles have only been found in a few isolated spots in the state, they have the potential to cause significant damage to their host plants, so gardeners should keep a watchful eye out for them in 2015!

8) Brown Marmorated Stink Bug (BMSB): This invasive pest was first discovered in the state in 2010. When I describe BMSB during presentations, I joke that it’s as if a mad scientist in a bad Sci-Fi movie had somehow crossed a Japanese beetle with a box elder bug.  Like Japanese beetles, BMSB will feed on hundreds of different types of plants: field crops, vegetables, fruits, and ornamental plants can all be damaged. In addition, BMSB has the habit of sneaking indoors in the fall like box elder bugs. In other parts of the US (such as Pennsylvania and Virginia), BMSM has been wreaking havoc on agricultural producers and homeowners alike. Luckily, this stink bug has been quiet the past few years in Wisconsin and we saw more of the same for 2014. While I only had half a dozen samples documented in the state this year, this is certainly a pest that everyone should be keeping an eye out for in the future.

Brown Marmorated Stink Bug (Halyomorpha halys); Photo Credit PJ Liesch
Brown Marmorated Stink Bug (Halyomorpha halys); Photo Credit PJ Liesch

Part 2: Coming soon

Miniature Walking Stick?

Every once in a while I get a report of a miniature “walking stick”.  We do have a few different species of walking sticks in Wisconsin, but the adults are typically 2″ – 3″ long.  We do, however, have some tiny insects called stilt bugs that pop up from time to time during the warmer months.  They’re often seen on flowers but can also be found at porch lights.  I usually find a few each year, although they can often be overlooked due to their small size.

At a quick glance, these insects can resemble small walking sticks but some key differences exist.  First of all, stilt bugs tend to be quite small: usually around 1/2″ long.  Their antennae are also very long with relation to their body and have swollen tips;  the antennae of our walking sticks lack these swollen tips.  A final difference is in the mouthparts of these insects.  Our walking stick species chew on the leaves of oak trees and other plants using mouthparts that function like scissors or pliers.  Stilt bugs consume a liquid diet of plant fluids and have a specialized “straw-like” mouthpart to suck up fluids.  In the image below, the straw-like mouthparts can be seen curling backwards under the body from the head.

Stilt Bug
A stilt bug (Family Berytidae). Photo courtesy of Beth McGrath.