Category Archives: Biting Insects

Masked Hunter Bugs: Another Kissing Bug Look-Alike

“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 cruzia 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 (Triatoma sanguisuga)—ranges from Latin America as far north as southern Illinois.

Eastern conenose kissing bug adult.
Eastern conenose kissing bug adult. Photo credit: Robert Webster, via Wikipedia

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.

Juvenile masked hunter bug camouflaged with debris.
Juvenile masked hunter bug camouflaged with debris. Photo Credit: Chiswick Chap, via Wikipedia

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.

Masked Hunter Bug Adult.
Masked Hunter Bug Adult. Photo credit: JP Hamon, via wikipedia

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:

  1. Masked hunter bugs are entirely dark while eastern conenose kissing bugs have red on their body
  2. Masked hunter bugs lack the projecting “conenose” present on the head of kissing bugs
  3. Masked hunter bugs have a bulging, “muscular” appearance of their prothorax (trapezoidal region behind the head) when viewed under magnification
  4. Masked hunter bugs have stout beak-like mouthparts while kissing bugs have long, slender mouthparts when viewed under magnification

Side-by-side comparison of a kissing bug and a masked hunter bug.
Side-by-side comparison of a kissing bug and a masked hunter bug. Photo Credit: Devon Pierret and PJ Liesch, UW Insect Diagnostic Lab. [Click for full sized version]
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: labs.russell.wisc.edu/insectlab/visual-id-guides/

Black Flies: Out for Blood

Mosquito season has officially kicked off in Wisconsin, meaning the omnipresence of repellents for the foreseeable future.  If mosquitoes have redeeming properties, it’s that they at least serve as food for a wide variety of animals and can even act as pollinators in some cases.  When mosquitoes bite, they do so with surgical precision that would make a phlebotomist green with envy.  Simply reading about mosquitoes might make you want to scratch, although on the spectrum of biting flies, things could be much more sinister…

Also very active at the moment in Wisconsin are black flies (Family Simuliidae) and our state is home to 30 species of these tiny sanguivores.  Black flies—or “buffalo gnats” due to their hump-backed appearance—are deceptive creatures for their small size (~ 1/8″ long).  You usually don’t notice them as much by sound like buzzing mosquitoes, but when they land to feed, these tiny flies are vicious.  Rather than using needle-like mouthparts to delicately probe for blood vessel like mosquitoes, black fly mandibles resemble the jagged edge of Rambo’s survival knife which they use in a “slash-and-slurp” approach.  These mouthparts slice into flesh to create a pool of blood which they then consume.  If this sounds unpleasant—it is!  Reactions to black fly bites can sometimes be severe, with fever and enlargement of nearby lymph nodes.  In addition, their sheer numbers can take a psychological toll and can be a strong test of one’s fortitude if you must be outdoors during peak black fly season.

Adult black fly taking a blood meal. Photo Credit: Credit: D. Sikes, via Flickr.

Of the 30 species in Wisconsin, only a handful actually bite humans.  Other species are “picky eaters” with a strong preference for other animals.  The species, Simulium annulus, specializes on common loons and in “bad” years the constant pestering can force adult loons to abandon their nests.  Other birds, such as purple martins and bluebirds can face high rates of chick mortality when the black flies are bad.  Pets, like dogs can commonly get bites and large pinkish welts on the soft skin of their belly.  Dairy cows can be harassed to the extent that feeding and weight gain is greatly reduced and milk production all but ceases.  In some cases, large animals including deer, cows, and horses have been killed outright by black flies.

With that said, if you’ve ever encountered an outbreak of black flies, you’d likely remember.  If you haven’t bumped into black flies before, you’re perhaps in a good spot on the map.  The larvae of many black fly species tend to be associated with streams and rivers, meaning that geography can play a role with outbreaks.  Within the state, areas near the Wisconsin River and other large rivers and streams tend to see the most intense black fly activity.  Black flies can be even worse to the north.  These insects can be notoriously bad in the Boundary Waters Canoe Area in June, and in Canada black flies have even been enshrined in film and a surprisingly catchy folk song.

Black fly larvae in a river. Photo credit: GlacierNPS via Flickr

If there’s good news about black flies, it’s that the adults are short-lived.  Wisconsin tends to see a blitz of activity spanning a 2-3 weeks in late spring.  When black flies are active, the best approach is to layer up with long sleeves, break out the repellents like DEET, and use a head net if needed.  If you’re in an area with intense black fly activity, cutting back on outdoor activities until these insects run their course for the year may be the simplest option.

What’s Trending? Ticks and Lyme Disease

This month’s post features contributions from Dr. Bieneke Bron


As stories about measles and vaccinations circulate in the news, it’s easy to lose track of other emerging health threats.  May is Lyme Disease Awareness month, and if you want to look at an emerging health threat particularly relevant to the Midwest, look no further than deer ticks and Lyme disease.

Adult female deer tick (Ixodes scapularis). Photo credit: Robert Webster / xpda.com / CC-BY-SA-4.0 via Wikipedia.

A Brief History of Deer Ticks and Lyme Disease:
The Lyme disease story is surprisingly new to Wisconsin and deer ticks are something that our grandparents didn’t have to deal with while growing up.  It wasn’t until the late 1960’s that our first deer ticks were documented in northern Wisconsin. At the time, this particular tick was known from more southern locations, so the first Wisconsin reports were noted as a curiosity in the scientific literature.  In actuality, this marked an early foothold of deer ticks in the region, which have spread rapidly.  Fast forward 50 years and deer ticks are widely distributed around Wisconsin and surrounding states.

Deer ticks are only one component of the Lyme disease equation. The spirochete bacterium Borrelia burgdorferi (or the closely-related B. mayonii) must be transmitted by these ticks to cause Lyme disease in humans.  Similar to the deer tick situation, Lyme disease has had an interesting recent history.  Research from the Yale School of Public Health suggests an ancient origin of Borrelia burgdorferi, but the first clinical cases of Lyme disease weren’t formally documented in the medical literature until the 1970’s.  At that time, an unusual cluster of juvenile arthritis cases with an accompanying rash helped researchers characterize the disease near Lyme, Connecticut*.  It wasn’t until the early 1980’s that the roles of deer ticks and Borrelia burgdorferi were recognized.

Skip ahead a few decades and the numbers for Lyme disease have increased steadily.  Today Lyme disease is the most commonly reported arthropod-borne disease in the US with over 40,000 confirmed and probable cases in 2017 alone.  Looking at Wisconsin’s statewide averages, approximately 20% of deer tick nymphs (juveniles) and 40% of adult deer ticks are carrying Lyme disease, which are alarmingly high percentages.

Deer tick nymphs (juveniles) next to chia seeds, sesame seeds, flax seeds and a penny for size reference. Photo Credit: Dr. Bieneke Bron, MCE-VBD.

Tracking Ticks with Mobile Technology:
With the changing tick and tick-borne disease situation over the last 50 years, understanding the factors that influence where and when ticks are encountered is more important than ever before.  Researchers at the Midwest Center of Excellence for Vector-Borne Disease and the Northeast Regional Center for Excellence in Vector-Borne Diseases have teamed up to develop The Tick App—a mobile app to help gather critical clues to better understand human exposure to ticks.  The app, available in iTunes and GooglePlay, not only allows the public to contribute valuable data to tick researchers, but the app provides helpful tips on tick identification, activity, and precautions to take.  During the tick season, the researchers will also identify ticks from the images submitted in the app.

As we move into peak tick season, Midwesterners should be aware of ticks and take appropriate precautions to protect themselves [Recommended reading: the ABCs of Tick Season].  Learn more about The Tick App by visiting thetickapp.org or follow on Twitter @TickAppOnTour.


*Interestingly, a 57-year old physician from Medford, Wisconsin, was diagnosed with the hallmark rash of Lyme disease (erythema migrans) in 1969 [Scrimenti 1970, Arch Derm].  Just imagine, Lyme disease being known as Medford disease…

September’s Mosquito “Madness”

While much of our insect activity in the Midwest slows down as summer draws to a close, some areas have seen an unusual increase in mosquito activity recently.  In Wisconsin, we generally expect mosquitoes to be “bad” from late spring through the summer months, but these pesky sanguivores typically fade away as autumn approaches.  September of 2018 has definitely bucked the trend, and mosquito pressure has been very high in many parts of the state and region this month.

As with other mosquito stories, the common denominator is water—in this case, the unprecedented rainfall events in late August and early September.  During this time, a series of storms dropped heavy rains across large swaths of Wisconsin and surrounding states.  Much of Wisconsin received several inches of rain, and some southern counties were bombarded with 10+ inches of rain in short periods of time.  Devastating flooding ensued, and it was only a matter of time before the mosquitoes responded as well.

Flooding caused over $200 million in damages in Wisconsin alone and set the stage for September’s unseasonably high numbers of floodwater mosquitoes. Photo Credit: PJ Liesch, UW Insect Diagnostic Lab

Surprisingly, not all mosquitoes can take advantage of floodwaters and some species have a strong preference for more permanent bodies of water, such as tree-holes, man-made objects, marshes, and other areas that can hold water for weeks or months on end.  Out of the 60+ mosquito species in the Midwest, it’s a much smaller subset that has flourished lately—a group appropriately called the “floodwater mosquitoes” for their ability to use temporary water sources to their advantage.  Members of this group, including the currently-abundant “inland floodwater mosquito” (Aedes vexans), tend to lay eggs in low-lying areas without water.  Laying eggs away from water may seem like a counterintuitive strategy, but the hardy eggs simply bide their time until heavy rains arrive—in some cases, years later.

Relying upon temporary resources can be a risky strategy; if the waters dissipate too quickly,  stranded larvae or pupae can be doomed.  Floodwater mosquitoes have evolved to race against the clock, with eggs that hatch shortly after exposure to water, followed by hasty growth and development.  Under the right conditions, it can take less than a week for these mosquitoes to make it to the adult stage.  This scenario is exactly what played out in our area—the rains came, followed shortly thereafter by hungry adult mosquitoes.

The “inland floodwater mosquito” (Aedes vexans) is currently abundant in the Midwest. Photo Credit: Sean McCann, via Flickr

With the unseasonably high mosquito pressure this September, one of the commonest questions has been, “when will it stop?!”  While the mosquitoes have undeniably been bad lately, we’re past the worst of the situation.  Mosquitoes and other insects are “cold-blooded” creatures, so there’s a general relationship between warmer temperatures and insect activity. Most of our insects in the Midwest become lethargic when temperatures dip into the 50s; below 50˚F mosquitoes are often too lethargic to fly, let alone pursue a blood meal.  We saw unusually high mosquito activity in early- and mid-September when temperatures remained in the 70s and 80s most days.  Looking at the weather for the near future, many parts of Wisconsin are expecting more seasonal temperatures, which will provide relief.  Mosquitoes might still be encountered on warm fall days, but evening temperatures may simply be too chilly for mosquitoes to go about their business and impending frosts will be the final “nail in the coffin” for September’s floodwater mosquitoes.

In the meantime, the best way to deal with the late season mosquitoes may be to embrace “flannel season” and put on some long-sleeved layers as a physical barrier to bites, and use  EPA-approved repellents as needed (such as on warm days).  Avoiding prime mosquito feeding times (dawn/dusk) and good mosquito habitat can help you avoid bites as well.  It may be sad to see summer go, but the changing leaves and cooler temperatures also signal the winding down of mosquito activity for the upper Midwest.

To Boldly Go Where Man Has Gone Before: Pests on the Move

Since the earliest days of mankind, we’ve excelled at exploring and expanding our presence to nearly every spot on the map With all our wanderlust, we’ve been equally adept at taking other species with us as we go—often with unintended consequences. 

In some situations, species have been deliberately moved by humans: livestock to the new world, the introduction of birds from Shakespeare’s plays into Central Park,  and even the notorious gypsy moth was transported from Europe in a failed attempt at an American silkmoth industry On top of that, there’s an extraordinarily long list of species that have been accidentally moved, with significant impacts Stowaway rats on the ships of European explorers and traders would be one of the most notorious examples Rats introduced to new island environments wreak havoc on native birds and reptiles by devouring vulnerable eggs Insects have also been transported around the globe with devastating results and some of North America’s most important and emerging insect pests originate elsewhere on the planet: Japanese beetle, emerald ash borer, brown marmorated stink bug, and the spotted lanternfly.

Aedes sp. mosquitoes preparing for a blood meal.  Photo Credit: Ary Farajollahi, Bugwood.org.

One of the insects best adapted to follow humans is the notorious mosquito Certain mosquito species (peridomestic species) possess traits that allow them to take advantage of conditions in areas disturbed by humans and thrive in those spots.  With humans came environmental modification, construction, and discarded trash of one kind or another.  Some mosquitoes might have originally relied on the water pooled in natural containers, such as rotted out tree stumps to reproduce, but can just as easily take advantage of water-filled containers, ditches, and other artificial habitats.

In modern times, automotive tires have become a key habitat for certain mosquito species Tires not only are perfect objects for holding water for extended periods, but they also provide the dark, sheltered habitat favored by some female mosquitoes looking to lay eggs Tires are an important way for mosquitoes, like the Asian Tiger Mosquito (Aedes albopictus) to be moved into and around the US (including the Midwest) Other species, like the Asian Rock Pool Mosquito (Ochlerotatus japonicus), are also easily transported in human materials.

Hyacinth flower sold from a local store, including a vase pre-filled with water. Photo credit: PJ Liesch, UW Insect Diagnostic Lab.

A recent case at the UW Insect Diagnostic Lab illustrates the ease with which non-native mosquitoes can be moved around the country In the first part of 2018, stores have been selling hyacinth bulbs in vases pre-filled with water as a way to force the bulbs to bloom into a flash of color during the dreary winter months In a recent discovery in southeastern Wisconsin, a vase purchased at a local store ended up yielding half a dozen larvae of the non-native Asian rock pool mosquito.  The exact origin of the mosquitoes isn’t known at this time.

A bonus surprise with the flowers—larvae of the Asian rock pool mosquito (Ochlerotatus japonicus). Animation credit: PJ Liesch, UW Insect Diagnostic Lab.

These mosquitoes won’t be much of a concern in the grand scheme of things as Ochlerotatus japonicus has been present in Wisconsin for over a decade and is already established hereHowever, such cases do leave open the possibility of non-native mosquitoes being moved into parts of the country where these pests have not been encountered beforeWhere humans go, pests will boldly follow.

Under the Microscope: Arthropod Trends of 2017

Over 2,500 cases flowed through the doors of the UW Insect Diagnostic Lab last year, ranging from the typical June beetles through bizarre creatures that most humans will never see in their entire lives (like the itch-inducing pyemotes grain mite).  Perhaps Forrest Gump said it best when he quipped, “life was like a box of chocolates—you never know what you’re gonna get.”  A distinction amongst insects, however, is that the “box” contains 20,000+ possibilities in Wisconsin alone and over well 1,000,000 globally.  With that said, a year at the UW Insect Diagnostic Lab is like having one humongous, box of really awesome chocolates, without all the calories.

Finding a pyemotes itch mite is like trying to find a needle in a haystack, except in this case these microscopic mites were in a farmer’s batch of corn. Photo credit: PJ Liesch, UW Insect Diagnostic Lab

With insects and related creatures, the weather can of course have a big impact and there definitely were examples of this in 2017.  The current cold winter aside, the last two winters had been otherwise mild, giving a few insects suited for warmer conditions a chance to inch their way northward.  Last spring and summer, this meant a bunch of sightings of an otherwise uncommon bee for our area known as the carpenter bee due to its habit of tunneling into unpainted cedar trim and other wood.  In a typical year, I might see a few cases out of the southeastern corner of Wisconsin, but 2017 had regular reports of these bumble bee look-alikes during the spring and summer months.  Similarly, praying mantids often meet their maker at the hands of a cold winter, but were surprisingly abundant in late summer and fall of last year.  Ticks were also extremely abundant last spring and with the rainy start to the summer, mosquito numbers were at an all-time high in some traps.  Mosquitoes were also a big deal in the news, with Wisconsin’s first confirmed reports of the Asian Tiger Mosquito last July.

Asian Tiger Mosquito (Aedes albopictus). Photo credit: James Gathany, Centers for Disease Control

The creature that amassed the most phone calls and emails in 2017 was the notorious Japanese beetle, which likely also benefited from the warmer than average winters these past few years.  For Wisconsin gardeners and farmers, the Japanese beetle is certainly a formidable foe, but at least there are ways to mitigate the damage.  In contrast, there’s another destructive pest wiggling its way into the spotlight in the state, which is much more difficult to control—an invasive earthworm commonly known as the jumping worm.  While they may not be insects, these earthworms are creepy-crawly and can wreak havoc in  gardens and flower beds, so I received a fair number of reports and questions.  What stood out to me in last year was the rapidity with which these destructive worms have been moved around the state (moved—as in humans have moved soil, plants, mulch, and similar materials).  Jumping worms were first found in the state in 2013 (in Madison), but have now been spotted in roughly half of the counties in Wisconsin.  To make matters worse, we don’t have any highly effective tactics to prevent these worms from turning rich garden soil into the consistency of dry, crusted coffee grounds—gardeners beware!

Speaking of invasive species, the emerald ash borer has continued its march through the state and now has footholds in some of our northern counties including Chippewa, Douglas, Eau Claire, Marathon, Marinette, Oneida, and Sawyer counties.  Unfortunately, our greatest concentrations of ash trees are in the northern part of the state (e.g. black ash in swampy areas), and the loss of ash from northern wetland areas could result in significant ecosystem effects.  Other recent invaders like the spotted wing drosophila and the brown marmorated stink bug had busy years as well.

Rusty patched bumble bee (Bombus affinis) visiting a flower in Middleton, WI. Photo credit: Rick Terrien

In other insect news, it seemed to be a good year for monarch butterflies in 2017, and the rusty-patched bumble bee finally made it onto the federal endangered species list. I was pleasantly surprised by a number of confirmed sightings of the rusty-patched bumble bee in the state as well. Perhaps my favorite “bug” story for the year involved black widow spiders.  It’s not common knowledge, but we do technically have a native black widow species in the state (Northern Black Widow, Latrodectus variolus).  It’s a reclusive species and is rarely encountered in Wisconsin, but reports trickled in once or twice a week at some points during the summer months (details to follow in a future blog post).

With so many cases last year, we’re really only touching the tips of the antennae.  If you’re interested in hearing more of the unusual stories from the UW Insect Diagnostic Lab, I’ll be giving a “highlight” talk on May 4th on the UW campus.

 

 

 

Free Couch? Think Twice About Bed Bugs

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”.

Free Mattress_opt
One of the many free items showing up around college towns these days. Photo Credit: PJ Liesch, UW-Entomology.

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.

Adult bed bug. Photo Credit: Gary Alpert, Harvard University, Bugwood.org
Adult bed bug. Photo Credit: Gary Alpert, Harvard University, Bugwood.org

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.

Bed Bug Signs_opt
Classic bed bug signs: black spots from digested blood and whitish eggs (~1mm long). Photo Credit: PJ Liesch, UW-Entomology.

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!

 

Zika: An Issue in Wisconsin?

With mosquito season nearly upon us and all the headlines about Zika Virus in the news, a big question at the moment is: will Zika be an issue for us in Wisconsin?  Based on what’s known about the Zika Virus and the mosquitoes that transmit it, it’s unlikely that Zika will be a major issue for us in the state.  Certainly, we’ll get cases of Zika in Wisconsin, but these will almost certainly be from individuals that have travelled to areas with active Zika infestations.  Overall, if we look at the bigger picture, a much bigger concern should be deer ticks and Lyme Disease, which affects thousands of Wisconsinites each year.

The Zika situation is an interesting one.  The Zika virus itself was first discovered in Africa in the 1940’s and has been found in parts of the eastern hemisphere for decades.  It wasn’t until very recently that it popped up the western hemisphere.  Because the Zika Virus is linked to a number of serious health issues, such as microcephaly in newborns, it certainly can pose significant health risks—hence the headlines and the concern.

However, the virus is only half of the story—the other half being the mosquito species (vectors) capable of transmitting the virus to humans.  Two mosquito species are associated with Zika virus and other viral diseases such as Chikungunya and Dengue: the Yellow Fever Mosquito (Aedes aegypti) and the Asian Tiger Mosquito (Aedes albopictus).  The good news for us in Wisconsin is that neither of these mosquito species are native to our area, and these species have never been found in the state (additional surveys are being conducted to look for them).  With that said, there may end up being some Zika cases in Wisconsin associated with travel to areas where Zika is widespread, but the absence of the two mosquito vectors responsible for transmission will greatly reduce the chance for transmission occurring within the state.

Estimated range of Aedes albopictus and Aedes aegypti in the United States, early 2016. Map source: Centers for Disease Control and Prevention.
Estimated range of the Asian Tiger Mosquito (Aedes albopictus) and the Yellow fever Mosquito (Aedes aegypti) in the United States, early 2016. Map source: Centers for Disease Control and Prevention.

While the Yellow Fever Mosquito and the Asian Tiger Mosquito don’t occur here, there still is reason to be vigilant about mosquitoes.  With as many as 60 or more different mosquito species in the state, there are a number of other mosquito-borne diseases that do occur in our area.  Our best example would be West Nile Virus transmitted by the Northern House Mosquito (Culex pipiens).  While West Nile cases can vary dramatically from year-to-year, we’ve historically had issues with West Nile in our area, and human deaths have occurred in the past.

Aedes sp. mosquitoes preparing for a blood meal. Photo Credit: Ary Farajollahi, Bugwood.org.

When it comes to mosquitoes in general, there are several approaches to keeping yourself and your family members safe. Around the yard, one of the most important things is to reduce or eliminate standing water to help eliminate mosquito breeding sites.  Toys left out in a sandbox, old tires, clogged gutters, birdbaths with stagnant water and anything else that collects and holds water could be a potential breeding site for mosquitoes.  Using EPA approved repellents, such as DEET, Picaridin, or others when working or relaxing outdoors will offer protection from bites.  Lastly, wearing long sleeves, avoiding outdoor activities during prime mosquito feeding times (dawn/dusk), or simply staying indoors can also protect you from mosquitoes.

 

Wisconsin’s Top Insect Trends of 2015 (#10 – #6)

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.

Deer Tick
Adult female deer tick. These ticks can now be found throughout the state and roughly 40% of adults are carrying the microorganism responsible for Lyme Disease. Photo credit: Scott Bauer, USDA Agricultural Research Service, Bugwood.org

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!

Lecanium Scale
Lecanium scales producing sticky honeydew (clear droplets).  Photo credit: Ronald S. Kelley, Vermont Department of Forests, Parks and Recreation, Bugwood.org

 

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.

Japanese Beetle
The infamous Japanese Beetle. Photo credit: David Cappaert, Michigan State University, Bugwood.org

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.

Up Next, Part III:  Wisconsin’s Top Insect Trends of 2015 (Numbers 5-1) 

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.