Category Archives: Pollinators

2018’s Top Trends from the Diagnostic Lab (Part 2)

In this post, we’re continuing to count down the University of Wisconsin Insect Diagnostic Lab’s top arthropod trends of 2018. This is the second half of a two part series; the first half can be found here.


5) White-Lined and Other Sphinx Moths:
The white-lined sphinx moth (Hyles lineata) can be a common species, so encountering one of the 3 inch long hornworm caterpillars isn’t unusual. However, these caterpillars can also be encountered in massive road-traversing hordes if the conditions are just right. From midsummer onwards, large numbers of these caterpillars were observed around the state—in some cases by the tens of thousands. If you didn’t spot any of the caterpillars themselves, you might have encountered the large adult moths with their hummingbird-like behaviour in late summer. Several other sphinx moths species also had a strong presence in 2018, such as the clearwing hummingbird moths and the tobacco and tomato hornworm caterpillars which can regularly be encountered in gardens as they munch away on tomato and pepper plants.

Large, dark-colored hornworm caterpillar of the white-lined sphinx moth on a plant
Large, dark-colored hornworm caterpillar of the white-lined sphinx moth. Photo submitted by Ted Bay, UW-Extension

4) Sawflies:
Sawflies, the caterpillar copycats of the insect world, are a diverse group, so they’re always present to some extent. Last year saw an unexpected abundance of two particular types in Wisconsin—the dogwood sawfly and the non-native Monostegia abdominalis, which feeds on creeping Jenny and related plants from the loosestrife group (Lysimachia species). While sawflies are plant feeders, dogwood sawflies can also damage the soft wood of a home’s siding or trim when these insects excavate small chambers to pupate in. The UW Insect Diagnostic Lab saw a distinct bump in reports of wood damage from the dogwood sawfly last year.

Whitish larva of the dogwood sawfly curled up on a dogwood leaf
Larva of a dogwood sawfly showing the whitish, waxy coating. Photo Credit: PJ Liesch, UW Insect Diagnostic Lab

3) Armyworms:
True armyworms (Mythimna unipuncta) can be a dynamic and sporadic pest in the Midwest. This species doesn’t survive the cold winters of our area, so adult armyworm moths must invade from the south each spring. Depending on national weather patterns, the arrival of the adult moths can vary significantly from year to year. If an early mass arrival is followed by abundant food and ideal conditions for the ensuing caterpillars, large populations can result. Once they’ve arrived, true armyworms can go through 2-3 generations in the state and this second generation of caterpillars made an alarming appearance in mid-to-late July. Under the conditions last summer, massive hordes of these caterpillars decimated crop fields before marching across roads by the tens or hundreds of thousands to look for their next meal. In some cases, that next meal included turfgrass, meaning that some Wisconsinites came home from work to biblical hordes of caterpillars and half-eaten lawns in late July.

Striped caterpillar of the true armyworm
Caterpillar of the True Armyworm (Mythimna unipuncta). Photo Credit: Lyssa Seefeldt, University of Wisconsin-Madison Extension

2) Monarch Butterflies:
Much to the delight of fans and conservationists, the iconic monarch butterfly (Danaus plexippus) appeared to have a banner year in the Midwest in 2018. Reports and observations of high numbers of monarchs poured into the Insect Diagnostic Lab during the summer months. As comforting as these reports were, the butterflies still faced a perilous 2,000 mile journey to reach their overwintering grounds in Mexico.  The most consistent measurement of the eastern monarch population comes from estimating the area occupied by the densely-packed overwintering butterflies.  In late January the latest count was released with encouraging news—the eastern monarch population is up 144% over last year and is estimated to be the largest in over a decade.  In contrast, the western monarch population overwinters in southern California and has recently dipped to alarmingly low numbers. Regardless of the winter assessments, monarchs face tough challenges and Wisconsinites are encouraged to help conserve this iconic species.  The Wisconsin Monarch Collaborative recently launched a website with resources for those wishing to join the effort.

Seven monarch butterflies nectaring on a flower
Multiple monarch butterflies nectaring on a single plant in August. Photo Credit: PJ Liesch, UW Insect Diagnostic Lab

1) Floodwater Mosquitoes:
Mosquitoes snagged the top spot on 2018’s list for good reason. The upper Great Lakes region is home to over 60 different mosquito species, but one subset—the “floodwater” mosquitoes—drove the storyline last year and impacted outdoor activities through much of the spring and summer months. Mosquitoes in this group, such as the inland floodwater mosquito (Aedes vexans), flourish when heavy rains come. Last year’s mosquito season kicked off in force with a batch of pesky and persistent floodwater mosquitoes just before Memorial Day weekend. Mosquito monitoring traps in southern Wisconsin captured record numbers of mosquitoes shortly thereafter. Later in the year, the Midwest experienced an unprecedented series of severe rainstorms, setting the stage for an encore performance of these mosquitoes. It was this second explosion of mosquitoes that caught the attention of anyone trying to enjoy the outdoors in late summer—a time of the year when mosquitoes are typically winding down in the state.

Ephemeral pools of water created ideal conditions for floodwater mosquitoes in late summer. Photo Credit: PJ Liesch, UW Insect Diagnostic Lab

Sphinx Moths—Hovering at a Flower Near You

If you’ve watched the flowers in your yard or local park recently, you might have noticed some surprising visitors hovering at the flowers—the hummingbird-like sphinx moths.  Several species in the “sphinx” or “hawk” moth group (Family Sphingidae) are known for their day-flying, hummingbird-like behavior.  From a distance these moths can easily be mistaken for hummingbirds as they skillfully maneuver from flower-to-flower sipping nectar with their long mouthparts.

One of the commonest members of this group in Wisconsin is the white lined sphinx moth (Hyles lineata).  With a wingspan of nearly 4 inches, it’s easy to understand why this species can be mistaken for a hummingbird as it feeds.  The greyish adults are easy to pick out and a white stripe on each forewing helps identify them in the field.  The caterpillars (hornworms) of this species reach nearly 3 inches in length and can feed on a wide range of plants.  While this species is regularly encountered in the Midwest, this year has been especially good for white-lined sphinx moths in Wisconsin.  In mid-to-late July I received many reports of the caterpillars—sometimes in astounding numbers.  In several instances, “outbreaks” of tens of thousands of these large caterpillars were spotted as they migrated across roadways from agricultural fields.  The multitudes of caterpillars have since pupated and transformed into nectar-loving moths—leading to a recent spike of sightings.

White-lined sphinx moth (Hyles lineata). Photo Credit: Andy Reago & Chrissy McClarren; Wikipedia

In addition to the white-lined sphinx moth, several other hummingbird-like sphinx moths have been common this year—the “clearwing” hummingbird moths (Hemaris spp.) and the Nessus sphinx moth (Amphion floridensis).

The rusty-colored “clearwing” moths (Hemaris spp.) are smaller than the white-lined sphinx moth, and have a wingspan of approximately 2 inches.  Their shaggy appearance and patches of yellow coloration lend a resemblance to large bumble bees.  Characteristic transparent “windows” in the wings help identify these moths.  Several Hemaris species can be encountered in the Great Lakes region with subtle differences in appearance and biology.  Both the “hummingbird clearwing” (Hemaris thysbe) and the “snowberry clearwing” (Hemaris diffinis) can be common, while the “slender clearwing” (Hemaris gracilis) is associated with pine barrens and is rarely encountered.

The hummingbird clearwing moth (Hemaris thysbe) showing the transparent “windows” in the wings. Photo Credit: Andy Reago & Chrissy McClarren; Wikipedia

The “Nessus Sphinx” (Amphion floridensis) is another hummingbird mimic that was commonly reported earlier in the summer.  Although somewhat similar in size and coloration to the Hemaris clearwing species, the Nessus sphinx moth has opaque wings and two distinct yellow bands across the abdomen.

The Nessus sphinx moth (Amphion floridensis) in action. Photo Credit: PJ Liesch, UW Insect Diagnostic Lab

In addition to being a joy to observe, sphinx moths are a great example of “non-bee” pollinators.  Their unique behavior and anatomy allows them to form interesting relationships with some of the plants they pollinate.  In an extreme example, the Christmas Star Orchid (Angraecum sesquipedale) from Madagascar possess extremely long tube-like floral structures which contain the nectar.  Upon learning of the unique anatomy of this orchid, the famed naturalist Charles Darwin speculated that a moth with equally long mouthparts must exist to pollinate them.  It took over a century to document, but a sphinx moth wielding foot-long mouthparts was finally observed pollinating the Christmas Star Orchid.

Wisconsin’s Top Insect Trends of 2015 (#5 – #1)

In this post, we’re continuing to count-down 2015’s top insect trends in the state.  This is the final post in a three part series.  Part I (2015’s diagnostic lab statistics) can be found here and Part II (Top Insect Trends Numbers 10-6) can be found here.

5) Pollinators
With all the headlines about bees, it’s not surprising to see pollinators in the top insect stories again in 2015.  Similar to other years in the recent past, honeybees and other pollinators have been facing declines.  Unfortunately, Wisconsin saw some of the highest honeybee losses in the country, with over 60% colony loss during the 2014-2015 period.  Some good news over the past year has been the development and release of pollinator protection plans.  A federal pollinator protection plan was released in May with the goals of reducing honeybee losses, increasing the population of Monarch butterflies, and increasing pollinator habitat.  In addition, a Wisconsin pollinator protection plan was announced in 2015, and was just released in January of 2016.   Due to the recent declines and their importance to agriculture in the state and nation, pollinators will continue to be in the spotlight in the future.

A ground nesting bee (Colletes sp.) near the stump of the former President's Oak on the UW-Madison campus. Photo Credit: PJ Liesch
A ground nesting bee near the stump of the former President’s Oak on the UW-Madison campus. Photo Credit: PJ Liesch

4) Spring caterpillars
An unexpected insect trend in the spring of 2015 was the surprising abundance of a number of caterpillar species feeding on plants in the landscape.  Caterpillar species, such as the humped green fruitworm, speckled green fruitworm, eastern tent caterpillar, forest tent caterpillar, gypsy moth caterpillar, and the euonymous caterpillar are typically present to some extent, although their numbers have been low the past few years.  For a number of potential reasons, these species had a great spring and during a period in May and June, caterpillars made up roughly 30% of the cases coming in to the diagnostic lab.  Weather patterns (i.e., rainy weather) and natural predators/parasites/diseases can have significant impacts on caterpillar populations each year, so it’ll be interesting to see if we’re faced with a plethora of caterpillars again in 2016.  Additional details of this story were featured in a blog post last June.

3) Viburnum Leaf Beetle
In terms of a new emerging pest with the potential to impact a commonly planted landscape shrub, Viburnum Leaf Beetle is near the top of the list.  As of late 2014, we only knew of a single infested viburnum bush in northern Milwaukee County, which raised the question: is the infestation small enough to contain and/or eradicate?  Some ground truthing this past spring identified many new infestations in SE Wisconsin, in many cases miles from the original site.  At the moment, the viburnum leaf beetle seems to be centered around the four county area where Milwaukee, Waukesha, Washington, and Ozaukee counties meet.  While this insect only feeds on viburnums (and related plants like Arrowwood), the damage can be significant.  It may be some time before this pest spreads elsewhere in the state, but if you have viburnum plants in your yard in SE Wisconsin, be weary!  Additional details of this case were featured in a post last June.

VLB Damage
“Skeletonizing” feeding damage from adult viburnum leaf beetles. Photo courtesy of Paul Weston, Cornell University, Bugwood.org

2) Brown Marmorated Stink Bug
Populations of the invasive Brown Marmorated Stink Bug increased dramatically in 2015 and this insect takes the overall #2 spot in this list (up from #8 last year).  This invasive species was first spotted in the state in 2010, and each year a handful of lone adults have been found in Wisconsin.  In the fall of 2015, we had more sightings of BMSB (30+), than in the past 5 years combined! (Spoiler: this trend has continued into early 2016)  At this point, the “hot spots” in the state are: Dane County, the greater Milwaukee area, and the Fox River Valley.  In addition to being an indoor nuisance pest, BMSB can also feed on and damage a wide variety of plants in home gardens, agricultural fields and orchards.  In other places in the country, the first reports of plant damage have typically been noted ~3-5 years after the initial detection of this species.  With that said, 2016 could be the year that BMSB really takes off and starts wreaking havoc for gardeners and agricultural growers alike.  Additional details of this case can be found in this post from last October.

1) Magnolia Scale
While scale insects have already been mentioned in the “sucking insects” section (#9 on the list), one species in particular, the Magnolia scale (Neolecanium cornuparvum), seemed to stand out amongst all other insects in 2015.  This species is often present in low numbers in the state, but the conditions must have been perfect for their populations to explode last year.  During the months of June and July, reports of Magnolia scale were coming in on almost a daily basis.  Being one of the unusual scale insects, Magnolia scale adults look more like a fungus than an insect (note the whitish blobs in the image below).  Not only did this bizarre looking species pummel Magnolia shrubs and trees in many parts of the state, but the honeydew produced by these insects rained down below, attracting ants and yellowjackets and leading to the growth of unsightly black sooty mold.  A number of predators, parasites, and diseases typically keep Magnolia scale in check, but with the extremely high infestations noted last year, it’s likely that we’ll continue to see some Magnolia scale activity into 2016.  If you experienced magnolia scales first hand, there’s a helpful factsheet available here.

Magnolia twig coated with whitish, fuzzy magnolia scale adults.

Be Thankful for Insects

As we’re sitting down for the Thanksgiving feast, there’s one thing we should all be thankful for, whether we realize it or not: insects.  It turns out that insects are involved one way or another with many of the foods we’ll be stuffing ourselves with.  Without those very insects, the dinner table would have a drastically different appearance.

Squash Bees (Peponapis pruinosa) inside of a cucurbit flower. These bees are partially responsible for your pumpkin pie. Photo Credit: USDA ARS
Squash Bees (Peponapis pruinosa) inside of a cucurbit flower. These bees are partially responsible for your pumpkin pie and squash dishes. Photo Credit: USDA ARS

Think about the ubiquitous pre-dinner veggie platter at the family get-together.  If you already have seeds of carrots, celery, broccoli, and cauliflower, you can technically grow a batch of these crops just fine.  But with many vegetables, insect pollinators help produce that next batch of seeds.  Then there’s the cheese and cracker appetizer plate.  Being made from wheat (a wind pollinated plant), crackers technically don’t require insects to be produced.  You might also think that cheese (being a dairy product) is also unaffected by insects.  However, insects play a role in the production of alfalfa, which is a common food source for cows.  Without alfalfa, cheese, butter, and other dairy products would be harder to produce, and could be tough to find at the grocery store.  Oh, and without insects as pollinators, we wouldn’t have the almonds on the outside that smoked cheese log anymore.

Some of the items from the main course don’t rely on insects to make it to the table: turkey and potatoes.  Technically, wild turkeys can feed on insects as part of their diet, although they can feed on many other things as well.  If you’ve recently seen The Martian, you’ll remember astronaut Mark Whatney growing potatoes sans insects to survive, so those mashed potatoes would still make it to the table.  Bread and dinner rolls (from wind-pollinated wheat) would still be around.  We could also have certain vegetables that can self-pollinate without insects, such as lima beans (who doesn’t love a great big helping of lima beans…).  However, some big players on the dinner table rely on insects for pollination, including the many types of squash.  One of the most crucial Thanksgiving dishes, the cranberry sauce, wouldn’t be around as cranberries rely on bees for pollination.  It’d be a sad Thanksgiving if there were no cranberry sauce.

As we finish dinner and get ready to watch football, it’ll be about time for dessert and coffee to perk up. Unfortunately, that’s where some bad news comes in.  Without insect pollinators, we wouldn’t have pumpkins to make the traditional pumpkin pie, or some of the spices, like nutmeg, to flavor it.  The whipped cream to go on top?  Well that’s one of those dairy products that could be hard to come by in a world without alfalfa.  Maybe you don’t care for pumpkin pie and prefer apple, cherry or blueberry pie instead?  Those fruits all rely on insect pollinators as well.  Maybe we’ll forget about dessert and go right for that coffee so we don’t fall asleep on the couch.  Just keep in mind that insects are also responsible for the pollination of coffee plants.

When it comes to Thanksgiving tomorrow, be thankful for family, friends, good health, and also the insects that helped put a lot of that great food on the table.

The Plight of the Monarchs

Just like the bees, the beloved Monarch (Danaus plexippus), is facing declines in North America.  Unlike the bee declines, which seem to be the result of a complex amalgam of factors, a major factor jumps out when it comes to monarch declines: habitat loss.  Simply put, we’ve gotten rid of much of the formerly ubiquitous milkweed in the Midwest.  There’s a number of reasons for this, ranging from continued land development, farm subsidies that have resulted in the cultivation of non-crop land, and heavy use of herbicide resistant crop varieties.  One scientific report suggests that the Midwest has lost nearly 60% of its milkweed over the past fifteen years.

Reared adult monarch prior to release, August 2008; Photo credit: PJ Liesch

We all probably learned the general story of the monarch in elementary school: a spring northward migration, milkweed, eggs, more milkweed, striped caterpillars, even more milkweed, orange and black butterflies, and finally migration down to Mexico after a few generations (there’s a great migration video here).  It’s bad enough that the sole summer food source of the monarchs (milkweed) has been disappearing, but monarchs are actually fighting a multi-front battle, as their overwintering habitat is disappearing as well.  Over the past few decades, much of the overwintering territory in Mexico has been lost, degraded, and fragmented by logging (both large and small scale).  What’s really concerning is that the overwintering territory isn’t all that big to begin with, making the insects vulnerable to extreme weather events.  A brutal winter storm in January of 2002 killed roughly 75% of the monarchs at some overwintering sites.  If monarchs keep getting squished into smaller and smaller areas, all it could take is a few bad winter storms to crash their numbers. Talk about putting all your eggs into one basket. . .

So why the fuss about monarchs now?
Over the past two years, the number of monarchs overwintering in Mexico has been the lowest in the history of the annual surveys.

Monarch Population Chart

With enough support, could we also pull the iconic monarch out of harms way?  Having the assistance of the President of the United States certainly helps.  Just yesterday, the white house announced that the Pollinator Task Force (created in 2014) has released its plan to help pollinators.  The three main goals of the plan are: 1) reduce honey bee losses to sustainable levels, 2) preserve the monarch population in the US, and 3) increase and improve pollinator habitat (full details here).

This isn’t the first time we’ve recognized a species at risk and created a recovery plan.  A classic success story: the iconic bald eagle.  It’s estimated that in the mid 1900’s there were just over 400 pairs of bald eagles left in the contiguous US.  These days, anyone passing through Sauk City, can tell you bald eagles have certainly rebounded.

While the Pollinator Task Force’s plan will take some time, there are things we can all do to immediately provide assistance for monarchs:
1) Plant milkweed to create a habitat for monarchs
2) Get involved with citizen science projects to educate ourselves and others
3) Use caution when using pesticides in the landscape to minimize impacts to monarchs, bees, and other beneficial species

 

Busy as a (Native) Bee

I think it’s safe to say that just about everyone knows and appreciates honey bees (who doesn’t love honey after all). Humans have a long history with honey bees and European settlers purposefully brought them over to the Americas. However, there’s another piece of the pollinator picture which is often overlooked and under appreciated: our many native bees.

Native Bee_opt
A native bee visiting flowers in the Allen Centennial Gardens on the UW-Madison campus, July, 2014. Photo Credit: PJ Liesch

How could they go unnoticed? A bee’s a bee, right?
Not quite—If you take the time to learn about Wisconsin’s bees, you might be surprised to discover that we have approximately 500 species of bees in Wisconsin alone. (Then there are the many flies and wasps that are often mistaken for bees, but I’ll save mimicry for another day.)  A common example of a native bee would be the metallic green “sweat bees” (Family Halictidae), although many different species exist within that family alone.

Most of our bee species are native, solitary creatures with their own unique habits.  With their solitary nature, each female makes her own nest and there’s no colony of relatives to defend (unlike honeybees).  With that said, our native bees tend to be rather docile, allowing for plenty of opportunities to observe them foraging at flowers or constructing their nests. Depending on the species, our native bees tend to nest in the ground (the females dig tunnels) or inside of hollow chambers.  These hollow chambers could be a tunnel made in wood or a hollow plant stem. Regardless of the nesting site, the story is similar: the female bees gather food (pollen and nectar) to stash away in the nests for their young. Depending on the species of native bee and the type of plants in the area, native bees can actually be more effective at pollinating than honey bees. Thus, the importance of these native bees is often overlooked and under appreciated.

A ground nesting bee (Colletes sp.) near the stump of the former President's Oak on the UW-Madison campus. Photo Credit: PJ Liesch
A ground nesting bee near the stump of the former President’s Oak on the UW-Madison campus. Photo Credit: PJ Liesch

Like honey bees, many native bees are facing declines for a number of reasons. One of the best things to do is to learn about native bees and other pollinators and to make your yard pollinator friendly by providing floral resources and nesting habitat.

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

Below you’ll find the third and final part of a series describing the Top 10 insect-related stories of 2014 from Wisconsin.


4) Hexagenia Mayflies and Fishing Spiders: If you love insects and/or fly fishing, you might have been thrilled to hear about the massive mayfly hatch along the Mississippi River in late July. These emergences happen yearly, but the mass emergence in the evening of July 20th was one of the largest in decades. We’re not talking about thousands or millions of insects, but billions of insects emerging at the same time. So many mayflies emerged simultaneously that the insects showed up on National Weather Service weather radar (read the full details here).  When these emergences occur, the insects can accumulate on bridges and streets making roadways slippery.

Hexagenia 20 July 2014
Mayfly emergence on the evening of July 20th. Source: National Weather Service.

The insect involved is the Hexagenia mayfly. The young (nymphs) live in the sediment at the bottom of the Mississippi River and feed on bits of organic matter in the water. The presence of the adults above water is truly an ephemeral phenomenon; it’s even reflected in the name of their group: the Order Ephemeroptera. Adult Hexagenia mayflies only live for a matter of hours, which leads them through a frenzied courtship period. Shortly thereafter, they’re done for.

Around the same time as the mayfly emergence, the fishing spider stories made their way around television, radio, and Facebook and the phone calls and emails came flooding in. Despite the hype, fishing spiders are native to Wisconsin and can actually be fairly common. Fishing spiders aren’t truly aquatic, but they do tend to hang out near water. They’re among our largest spiders in the state, and can be large enough to capture and feed on small minnows.

3) Spotted Wing Drosophila: One of our newest invasive species had another strong year in 2014. The spotted wing drosophila (SWD) is originally from parts of Asia, and was discovered in the US in 2008. Within two years, it had popped up in Wisconsin. Like other fruit flies, SWD loves fruit.  The main difference is that our run-of-the-mill fruit flies lay eggs in overripe or spoiled fruit.  In contrast, SWD females have a hacksaw-like egg-laying structure, which can be used to slice into ripe or ripening fruit to lay eggs. As a result, SWD has become a major issue for fruit growers in the state.  Late-season berry crops (raspberries, blackberries, strawberries) are hit the hardest. SWD has been found statewide, and will continue to be a major concern for late-season fruit growers for the foreseeable future.

2) Pollinators: You don’t have to listen to the news very long before you hear a reference to pollinators. Unfortunately, much of the news on the topic paints a bleak picture: pollinators of all kinds are in decline at the moment. Honey bees, bumble bees, other native bees, and butterflies like the Monarch are all facing declines. Unfortunately, it’s not a black-and-white situation, and there’s no simple solution to the issue at hand. Instead, many different factors, such as habitat loss, diseases, parasites, land-use practices, pesticides and other factors may all be involved one way or another.

We may not think of the connection to pollinators when we visit the grocery store, but without the pollination services of insects, the produce section would be scarce. It turns out that roughly a third of the world’s agricultural crops rely on pollinators. Without pollinators, you’d have a hard time finding apples, strawberries, melons, tomatoes, and many of our common food items.

Flowering plants in your yard provide resources to bees. Photo Credit: PJ Liesch
Flowering plants in your yard provide resources to bees. Photo Credit: PJ Liesch

If there’s a silver lining to the situation, it’s that attention has been brought to the topic. In June of 2014, the White House announced the creation of a pollinator health task force to develop a national strategy to help prevent pollinator losses and help improve pollinator habitat.  While it may seem like a small step, individuals can help pollinators by making their own yards pollinator friendly. Incorporating native plants into the landscape, providing nesting habitat for solitary bees, and using caution with pesticides are all ways to help pollinators in our own yards.  Tips for accomplishing this can be found here.

1) Emerald Ash Borer: The emerald ash borer (EAB) continues to be one of the biggest insect stories in the state. This invasive pest is originally from Asia, but has been wreaking havoc on Wisconsin’s ash trees since 2008. Spread within the state seemed to progress slowly at first, but 2014 saw dramatic changes in our quarantine map in the state. In early 2014, we had a total of 21 Counties quarantined for EAB. By the end of the year, 16 additional counties had been added to the map to bring the total up to 37 counties. While most of the quarantined counties are in the southern half of the state, Douglas and Oneida counties in the north are also quarantined. Unfortunately, this destructive pest is difficult to detect and easily transported in firewood, which means that this pest will only spread and the situation will worsen over time. While we have options to protect individual ash trees (available here), we don’t have a way to protect ash trees in woodlots or forested areas. Since its introduction into the US, the emerald ash borer has killed tens of millions of ash trees. With over 700 million ash trees in the state, Wisconsin has a lot at stake.