New York State IPM Program

September 28, 2017
by Joellen Lampman
Comments Off on In praise of messiness

In praise of messiness

KEMPTVILLE, ONTARIO. — On my twice-monthly drive on Highway 416 between Prescott and Ottawa, I pass the sign for Kemptville, a town of about 3,500 which lies roughly 40 km north of the St. Lawrence. It has a rich history, and no doubt is a fine place to live, but one of these days I need to stop there to verify that Kemptville is in fact a village of surpassing tidiness. (It’s Exit 34 in case anyone wants to take some field notes and get back to me.)

Most of us would prefer not to live in totally unkempt surroundings, but Western culture may have taken sanitation a bit too far. Claims that cleanliness is next to godliness have yet to be proven by science, but research does indicate a neat, well-coiffed landscape is bad for bees and other pollinators.

Dandelions are an essential early-season flowers for our 416 species of wild bees in New York.

With all due respect to honeybees, they are seldom required to produce fruits and vegetables. Please don’t spread this around, as I do not want to tarnish their public image. But the fact is that wild bees, along with other insects and the odd vertebrate here and there, do a bang-up job pollinating our crops, provided there are enough types of wild plants (i.e., messiness) around to keep them happy for the rest of the season.

As landscapes become neater and less diverse, wild bees cannot find enough natural foods to keep them in the neighborhood for the few weeks of the year we’d like them to wallow around in our apple or cucumber flowers. In sterile, highly manipulated environments like almond groves and suburban tracts, honeybees are critical.

Dr. Scott McArt, a bee specialist at Cornell’s Dyce Laboratory for Bee Research, says there are an estimated 416 species of wild bees in New York State. When I estimate stuff, the numbers tend to be less exact, such as “more than three,” but I’ve met Dr. McArt, and I trust him on this count. Dr. McArt is quick to point out that wild critters take care of things just fine in most places. He has cataloged exactly 110 species of wild bees visiting apple blossoms in commercial orchards, and in the vast majority of NYS orchards studied, honeybees have no bearing on pollination rates. My object is not to malign honeybees, but to point out that if we learn to live with a bit more unkemptness, we will improve the health of wild bees, wildflowers, food crops, and ourselves in the process.

Dr. McArt has cataloged exactly 110 species of wild bees visiting apple blossoms in commercial orchards, and in the vast majority of NYS orchards studied, honeybees have no bearing on pollination rates. There was a presentation about it at the 2015 Pollinator Conference.

Messiness also takes pressure off managed honeybees, an increasingly fragile species, by providing them a rich source of wild, non-sprayed nectar and pollen. Orchardists do not spray insecticides when their crops are flowering because they know it will kill bees. But many fungicides, which are not intended to kill insects, are sprayed during bloom. One of the unexpected findings of research done through the Dyce Lab is that non-lethal sprays like fungicides are directly linked with the decline of both wild bees and honeybees. But banning a particular chemical is not a panacea—the situation is far more complex than that. What is needed to save bees of all stripes is a real change in mindset regarding landscape aesthetics.

This garden at Bethpage State Park Golf Course is an excellent example of entropy. Primarily established with native wildflowers, there are also a significant number of volunteers. NYS IPM staff found over 100 different species of insects, primarily bees and wasps, taking advantage of the bounty.

Increasing the entropy on one’s property is as easy as falling off a log (which of course is a literal example of increased entropy). Pollinators need plants which bloom at all different times, grow at various heights, and have a multitude of flower shapes and structures. For greater abundance and diversity of wild flowering plants, all you need to do is stop. Stop constantly mowing everything. Choose some places to mow once a year in the late fall, and others where you will mow every second third year. Stop using herbicides, both the broadleaf kind and the non-selective type.

Before you know it, elderberry and raspberry will spring up. Woody plants like dogwoods and viburnums will start to appear. Coltsfoot and dandelions, essential early-season flowers, will come back. Asters and goldenrod (which by the way do not cause allergies), highly important late-season sources of nectar and pollen, will likewise return.

Despite their unassuming flowers, Virginia creeper attracts a large number of pollinating bees and wasps. Photo: Joellen Lampman

Wild grape, virgin’s bower, Virginia creeper and wild cucumber will ramble around, without any help whatsoever. However, you may choose to help this process along by sowing perennial or self-seeding wildflowers like purple coneflower, foxglove, bee balm, mint, or lupine. Even dandelion is worth planting. You’ll not only get more wild pollinators, you’ll also see more birds. Redstarts, tanagers, orioles, hummingbirds, catbirds, waxwings and more will be attracted to such glorious neglect. No feeders required.

I strongly advocate for more chaos in the plant department, even if the local Chamber of Commerce or Tourism Board frowns upon it. Remember, just because you’re an unkempt community doesn’t mean you have to change the name of your town.

Many thanks to Paul for letting us share his piece! For more information on protecting pollinators and enhancing their habitat, visit the New York State Integrated Pest Management Program’s pollinators webpage.

August 8, 2016
by Lynn A. Braband
Comments Off on Wasps and Festivals

Wasps and Festivals

One of the great things about living in New York State in the summer and fall is the availability of numerous festivals. It seems like every area has several each weekend. Hard to choose! In addition to sudden downpours, yellowjacket wasps are one of the consistent nemeses of festival attendees. This is especially true in late summer and early autumn when the wasps are present in seasonally high numbers and are attracted to sweets and other food of the ubiquitous concession stands.

Yellowjacket

Yellowjacket

Reduce attractants

Although not eliminated, the risks associated with yellowjackets can be reduced. Festival managers and vendors need to pay particular attention to reducing the vulnerability of drinks, food, and waste. Trash cans should be emptied frequently and have lids that close tightly. Regularly police the grounds for discarded trash. Keep exposed food and drinks to a minimum, and provide lids for beverage containers. Every one of these tactics are core to the premise of sound IPM: prevention is your best defense.

Trapping yellowjackets

Some festival organizers have reduced the number of reported stings after adding yellowjacket container traps. The wasps are attracted to a sweet liquid inside the trap and then drown. On-going research at Cornell indicates that use of these traps may reduce the number of yellowjackets by as much as 30%. We and our partners have largely established traps on poles surrounding the concession stand area. Some vendors trap in the immediate vicinity of the concessions.

The suggested protocol is to start trapping about a week before the festival and to continue trapping through the festival. The traps should be serviced daily, especially immediately before and during the festival. There is also evidence that the traps do not merely intercept wasps that would have been present anyway but attract wasps. Thus the best use of the traps is probably when there will already to an attractant, such as concession stands. Some wasps may be able to escape the traps. Use of a surfactant, as dishwater soap, may reduce this.

Personal protection

IPM gets personal: Light-colored clothing is less attractive to wasps than dark- or brightly-colored clothes. Perfumes and strong-smelling soaps and perfumes may also attract them. Avoid erratic movement when a wasp is flying or crawling near you — by which we mean don’t try to shoo them away — or worse, swat them. Keep your food and drinks covered. It is far from pleasant to drink down a wasp! Insect repellents will not deter wasps.

For more information

Please check out our video on yellowjackets and other stinging insects.

June 9, 2016
by Joellen Lampman
Comments Off on For Wasps, Prevention Is Key — and the Time Is Now

For Wasps, Prevention Is Key — and the Time Is Now

Most of the wasps we’re too familiar with (and afraid of) are sociable with their own kind, building large nests in trees or underground. The problem is when they build nests under your eaves, picnic tables, or even (if you’re a farmer) under the seat of that baler  you’re about to rev up as part of your pre-harvest maintenance check.

At a distance these wasps make great neighbors. As predators of flies, caterpillars and other soft-bodied insects, they help keep their numbers in balance. And that balance, that ounce of prevention, is a core tenet of IPM. But wasps are trigger-happy, so to speak — grab that picnic table to move it out of the sun and you’ll wish you looked underneath it first.

We could talk about any wasp you want, but today we’re focusing on bald-faced hornets. Just know that you can also apply IPM’s preventive tactics — we’ll get to that later — to your standard-issue yellow jackets, paper wasps, mud daubers and honey bees.

Big nests for big bruisers: this carton nest is too close to home.

Big nests for big bruisers: this carton nest is too close to home.

Bald-faced hornets house their colonies in large, enclosed carton nests. Like most wasps (and bees) these mostly mild-mannered critters turn nasty when their nest is threatened. They don’t know you had no intention of harm. But when  bald-faced hornets live too close, yes, they represent a public health concern.

Bald-faced hornet, up close and personal. Courtesy Gary Alpert, Harvard U.

Bald-faced hornet, up close and personal. Courtesy Gary Alpert, Harvard U.

Did You Know…?

  • What’s in a name?: White-faced hornets can be easily identified by the large patch of white on their faces.
  • Family relations: This hornet is the largest yellow jacket species in North America.
  • By the numbers: A nest can contain hundreds of hornets, and most will attack to protect their queen.
  • Danger! White-faced hornets have unbarbed stingers, so they sting repeatedly. (Author’s note: Take it from me — disturb a nest and yes, you might get stung way more than you’d like.)
  • Beneficial insect: White-faced hornets are important predators of flies, caterpillars and other soft-bodied insects.
Only one way out of a carton home, but space enough for a battalion of angry moths to exit. courtesy Wikimedia Commons.

Only one way out of a carton home, but space enough for a battalion of angry moths to exit. Courtesy Wikimedia Commons.

Since technically it’s still spring and a chilly May slowed them down, you still have time. Inspect (in IPM lingo, “scout”) the aforementioned eaves, picnic tables, and outdoor equipment as well as the undersides of the railing on your porch or deck; that sort of thing. You’re looking for small carton nests that look like these, only way smaller. For other stinging wasps, keep and eye out for what looks like clots of mud (nifty inside, should you get a chance to dissect one) and the clusters of open cells, rather like honeycombs, that comprise a paper-wasp nest. Basically, you want to find a nest under construction, as it were — one with just a few workers ferrying back and forth to care for their queen.

Did You Know…?

  • Last year’s empties: See a scary-big nest? Most likely it’s from last year — and wasps don’t reuse them. On the other hand, a subtle scent left behind tells other wasps that this could be a good place to build a nest of their own. So get rid of empties.

Moving quietly on a warm-enough day, stake out a claim nearby and watch the nest for 15 minutes or so. See any wasps? You’ve got an active one. No wasps? Best to scrape the old nest off so they won’t worry you later.

How to get rid of them? At dusk or dawn (dawn is better — it’s usually cooler) get out there with a tall pole, a SuperSoaker, or a hose with a good nozzle on it (you want a focused, powerful stream of water) and knock them down one at a time. Then stomp on them. Need a light? Don’t shine it right on the nest; better yet, cover your light with red cellophane. (Wasps don’t register red.)

Looking ahead — for larger nests later in summer, ask yourself if the nest is close enough to where you live, work or play to pose a significant threat. If it’s at a distance, best to leave it be.

More prevention (core IPM!): cover outdoor garbage receptacles and pick up dropped fruit under fruit-bearing trees. Integrated pest management can help to determine if a bald-face hornet nest is a danger and what to do if it should be removed.

For more information visit:

For more information from the New York State IPM Program on other stinging insects, click here.

May 18, 2016
by Joellen Lampman
Comments Off on Dandelions? Wasps? Mice? For Every Season There Is a Purpose (But It’s Not Always Obvious)

Dandelions? Wasps? Mice? For Every Season There Is a Purpose (But It’s Not Always Obvious)

It’s spring fever. That is what the name of it is. And when you’ve got it, you want — oh, you don’t quite know what it is you do want, but it just fairly makes your heart ache, you want it so! — Mark Twain

For IPMers who answer homeowner questions, what many people want in spring is an answer to dandelions. These in-your-face, bright bursts of yellow are speckling lawns statewide. Homeowners that aren’t yet convinced how important these early flowers are to pollinators want them gone — now. The bad news (or good, depending on your perspective) is: it’s not the best time to do anything. The best time to control broad-leafed weeds is late summer and fall. (We covered this a couple of years ago: Dandelions – Love Them or Leave Them, but Don’t Spray Them.)

We have exactly the opposite problem with wasps and yellow jackets. Now is the time to prevent later problems because their populations are so low in spring.

Carpenter bee females create galleries or tunnels in dry wood during the spring. Bees bore into the wood, then turn 90 degrees to tunnel along the grain.

Identification is important! Is it a bee? Wasp? Bald-faced hornet? This carpenter bee will be managed much differently than other types of stinging insects.

Last autumn a homeowner had “a swarm of bees” take residence in the attic. A pest management professional removed the nest and sprayed an insecticide. When “the bees” were noted this spring, the homeowner worried that they were back for a repeat performance.

The homeowner admitted that he didn’t know if it was bees, yellow jackets, or paper wasps. Identification matters when deciding how to deal with a large active population (you can find pictures of different types of stinging insects here and a video here). But no matter what type of insect is currently scoping out his house, the IPM solution is the same. Find the opening and seal it properly. (Unless it’s a carpenter bee. For more information on them, check out our Get Rid of Carpenter Bees? Yes, Please! fact sheet.)

This soffet was likely damaged when a ladder slipped during a routine gutter cleaning.

This soffit was likely damaged when a ladder slipped during a routine gutter cleaning.

In the case of our nervous homeowner, a damaged soffit provides access for all sorts of critters. (The soffit connects the outside wall with the overhang on your roof.) Forget stinging insects. The 1/4″ to 1/2″gap is large enough for bats and mice to enter. (Mice are good climbers.) This is relatively easy to repair by reseating the soffit flush with the bottom. To learn more about sealing openings, you can’t go wrong with the NYS IPM publication Beasts Begone! A Practitioner’s Guide to IPM in Buildings.

When yellow jacket nests are this small, there is little risk in removing them manually.

When yellow jacket nests are this small, there’s little risk in removing them manually.

Along with inspecting your house and outbuildings for openings that provide access to stinging insects, take the time you’d have spent on dandelions to watch for queens starting new nests under decks and eaves. These small nests can be easily removed using a broom handle or stream of water. (We covered this last year: Inspect for Wasps and Avoid the Sting.)

Looking for yet more info on stinging insects? Seek no further: NYS IPM’s Stinging Insect IPM video and What’s Bugging You page.

July 10, 2015
by Joellen Lampman
Comments Off on Paper Wasps: Friend or Foe?

Paper Wasps: Friend or Foe?

Paper wasps are social, stinging insects that build open-comb nests. These nests are often found on the protected undersides of natural or man-made overhangs. Soft-bodied insects, nectar, and honeydew are important food sources for paper wasps. These insects can be a public health concern when they nest near human activity because of their potent sting.

Wood scraped off this split rail fence will be mixed with saliva and used as nest building material.

Did You Know…?

  • By the numbers: There are 22 species of paper wasps in North America. The two most common paper wasp species in the Northeast are the native northern paper wasp and the invasive European paper wasp.
  • Watching it’s figure: Paper wasps can be distinguished from other wasps and yellowjackets by its very thin “waist”.
  • What’s in a Name?: Paper wasps use their mandibles (jaws) to scrape wood from plants, decks, or siding and combine it with saliva to make a papery nest.
  • Danger!: Paper wasps have unbarbed stingers, so they can deliver multiple stings. European paper wasps in particular are very aggressive when protecting their nest.
  • Look-alikes: European paper wasps are often confused with yellowjackets due to their similar black and yellow color. This species can be distinguished by its dainty waist and the position of its legs when it flies, which dangle below its body. (Yellow jacket legs are much shorter and held tight against the body.)
  • Beneficial Predator: Paper wasps feed their larvae caterpillars which can be garden pests.

    Paper wasps can build their umbrella comb nests under any protected ledge or overhang. Although they are beneficial predators, paper wasps can deliver a painful sting.

    Paper wasps can build their umbrella comb nests under any protected ledge or overhang.

Integrated pest management can help to determine if a paper wasp nest is a danger and what to do if it should be removed. For more information visit:

For more information from the New York State IPM Program on other stinging insects, click here.

June 5, 2015
by Matt Frye
Comments Off on Inspect for Wasps and Avoid the Sting

Inspect for Wasps and Avoid the Sting

Yellowjackets, bald-faced hornets and paper wasps are stinging insects that nest on or near structures. While colony sizes start small, the population of stinging insects in nests grows over time and can result in hundreds to thousands of individuals in the case of yellowjackets. Whereas management of large nests requires the assistance of a professional, starter nests can be easily knocked down, repeatedly if necessary, to discourage future nesting. Here are some steps to inspecting for wasps to avoid the sting!

1. Inspection: starting in early June, weekly walks around the perimeter of your property or facility can be used to identify the start of stinging insect nests. This might include paper wasps, which create an open-comb nest, or yellowjackets and bald-faced hornets that create nests wrapped in a papery envelope.

2. Removal: early nests may only contain a few individuals. These can be knocked down with a pole or by spraying with a hose from a safe distance. It is advised that you wear thick clothing, and conduct work at night using indirect light (do not shine a beam of light directly at the nest). Red filtered light will not be detected by wasps.

IMG_1748  IMG_1775

3. Extermination: Once nests are on the ground, stomp on them to kill any adults or larvae that are inside.

IMG_1756

4. Repeat: if queens escape, they may return to rebuild the nest somewhere nearby. However, repeated removal of the nest will ultimately discourage wasps from nesting there.

Note: some yellowjacket species will nest in wall voids, and you will see wasps flying in and out of the space during your inspection. A vacuum can be used to reduce the number of wasps that nest in wall voids, as shown in this video.

Staples White Plains (2)

April 28, 2015
by Matt Frye
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Ground Bees Come in Peace

IMG_2500

A female ground bee

One of the first springtime insects that homeowners observe are ground bees. These insects create ant-hill like mounds in areas of bare soil with a ¼” opening in the center (about the thickness of a pencil). On warm, sunny days there may be dozens to hundreds of bees flying low to the ground among the mounds. Despite a general and perhaps debilitating fear of bees – the truth is that this species is relatively harmless and may not require any management. Here’s why:

 

  1. Ephemeral: ground-nesting bees are pollinators of early blooming flowers. Because their lifecycle is tied to the cycle of these plants, ground bees are only active for a short period of time in early spring.

    IMG_1784

    Two female ground bees hunker down in their burrows in response to movement.

  2. Solitary: fear of bees arises from the idea that disturbing a nest will provoke an entire colony of stinging insects. However, as it true of carpenter bees, cicada killer wasps, and mud dauber wasps, ground bees are solitary with only a single female bee per mound.
  3. Shy Gals: female bees make nests for the purpose of reproduction. After gathering nectar and pollen as food for their offspring, females will mate and lay eggs in the nest. While in the nest, females appear shy, and will retreat into the burrow if they see an approaching object.
  4. Males Hover, but Can’t Sting: All those bees you see flying low to the ground en masse – are males! And male bees do not possess a stinger. Their low, hovering flight is part of their effort to pair up with a female. Indeed, male ground bees are quite docile.

 

IMG_2508

Male ground bees cannot sting and are quite docile.

If you wish to discourage ground bees from living in your yard, an effective, safe and long-term solution is over-seeding with grass. By creating a dense lawn, bees will not be able to dig in the soil and will nest elsewhere.

For more information please see Ground nesting bees in your backyard!

March 17, 2015
by Joellen Lampman
Comments Off on The squirrels are coming, the squirrels are coming!!

The squirrels are coming, the squirrels are coming!!

“Spring work is going on with joyful enthusiasm.” ― John Muir

In other words, birthing season will soon be upon us. And though it’s fun watching animal families grow up in our backyards, it’s best that they don’t give birth within our buildings. Because female squirrels seek safe places to raise their young in late winter and early spring, now is the time to ensure they stay out of your attic.

Photo credit: Carosaurus

Give them an opening and squirrels will happily turn your attic into a nursery. Photo credit: Carosaurus

 

Your first step? Monitoring is key to sound IPM. In this case you want to inspect your building exterior, especially if you’ve had problems in the past. Since squirrels are climbing animals and there’s no way could you see all possible entry sites from the ground, you’ll need a ladder. If you find a likely entry hole, don’t close it without first determining if it’s active. Trapping an animal (or its nest) inside can provoke it to chew its way back out — or in. Monitor an opening by inserting a soft plug (crumpled newspaper works fine) into the hole. If the plug is still there after two days and you see no other signs of activity inside the building, it should be safe to permanently close the hole. What to close it with? Think galvanized sheet metal or galvanized metal mesh, which resist strong teeth.

Do you need to remove squirrels from the building? Trapping is the most common and successful method. By New York law, however, without a state-issued permit squirrels must be released on the property or humanely destroyed. Another method is to install one-way doors (also known as excluders) over entry holes. These devices allow animals to leave — but not re-enter — the structure. To be successful, one-way doors need to be combined with preventive exclusion (such as metal mesh and caulk) on other vulnerable sites on your building, since exclusion and prevention are also key IPM practices.

Photo credit: BillSmith_03303

Openings such as this one provide access for squirrels, raccoons, mice, rats, birds, stinging insects, bats, snakes, … Photo credit: BillSmith_03303

 

No rodenticides or other poisons are legally registered for squirrel control. Although a variety of repellents and devices make marketing claims about driving squirrels from buildings, their efficacy is questionable.

To prevent future problems, reduce squirrel access to the building by keeping trees and tree branches at least 10 feet away from the structure and make sure all vents are made of animal-resistant materials.

For information on IPM for nuisance wildlife, refer to Beasts Begone!: A Practitioner’s Guide to IPM in Buildings  and Best Practices for Nuisance Wildlife Control Operators.

(Adapted from Controlling Squirrel Problems in Buildings by Lynn Braband, NYS Community IPM Program at Cornell University)

October 24, 2014
by Mary M. Woodsen
Comments Off on Critters Can Do — Match the Pest and What It Does

Critters Can Do — Match the Pest and What It Does

Match the critter to what it does — or in one case, what natural force could kill it. (Answer key below.)

critter

can do

mouse 1 eats pests of crops or pollinates them — or both
cockroach 2 emerges from cocoon when it feels vibration of approaching host
aphid 3 makes tunnels within leaves
flea 4 killed by raindrops
wasp 5 squeezes through a hole the size of a dime
leaf miner 6 live weeks — perhaps months — without food
paper wasp

This wasp helps control pests while doing adjunct duty as a pollinator. Photo courtesy Ward Upham, Kansas State University, Bugwood.org.

leaf miner

This chrysanthemum leaf-miner is the larvae of a fly-family pest. Photo courtesy Central Science Laboratory, Harpenden Archive, Bugwood.org.

Answer key:

critter

can do

mouse 5
cockroach 6
aphid 4
flea 2
wasp 1
leaf miner 3

Where the links will take you:

  1. Some large stinging wasps eat crop pests; others help pollinate them. Some do both.
  2. Yes, different researchers say different things. Just know that cockroaches can survive without food for a couple of weeks and maybe much longer. (At need, “food” could include wallpaper paste, envelope glue, and more.)
  3. “For an aphid, a raindrop is something like what a refrigerator would be like falling on us,” said researcher Jeremy McNeil, an entomologist and chemical ecologist at the University of Western Ontario in Canada.
  4. Fleas can live a long time inside the cocoon they pupated in — until they sense a host nearby.
  5. Follow the link to a fun, one-minute video of a fat mouse scrambling through a tiny hole.
  6. Their name (they dig mines, as it were) gives them away — but you’d be surprised at how many different sorts of insects have larvae that burrow through something as thin as a leaf.

September 16, 2014
by Matt Frye
Comments Off on What Is That Wasp in the Window?

What Is That Wasp in the Window?

Those of us who work in “structural pest management” (think office buildings, schools, or homes) tend to see the same cast of characters each year: cockroaches, ants, termites and bed bugs to name a few. But every now and then an interesting critter will show up that has a neat story to tell. Enter Brachymeria fonscolombei.

The Situation. In the past few weeks, I’ve heard from homeowners who’ve found small, compact (1/8 – 1/4 inch), black and red insects in their windowsills — with no apparent explanation for their presence. Indeed, these are wasps. But unlike your garden-variety wasps, B. fonscolombei won’t sting you or your pets.

B. fonscolombei

B. fonscolombei parasitize fly larvae. Photo: M. Frye

How to ID It. Like other wasps in its family, the Chalcididae, B. fonscolombei has large, toothed, dark-red hind femurs with a white dot. And parasites they are — but not the kind that could ever make us sick.

The Story. Brachymeria fonscolombei lay their eggs in the larvae of flies — especially house, bottle, and flesh flies. Finding them in your home follows a series of rather graphic events. It goes like this: not too long ago, a small animal — a mouse, say — died within your walls. Flies attracted to the scent laid their eggs on its body. When those  eggs hatched into larvae (“maggots” in the common lingo) along came B. fonscolombei — and laid its eggs in them. After three weeks or so (or if overwintering, as much as five or six months) a single adult wasp emerged from each maggot and looked for a way to get outdoors.

carcass

Small animal carcasses are food for flies such as this green bottle fly. Photo: J. Gangloff-Kaufmann.

Larvae

Flies lay eggs on food sources that develop into maggots — fly larvae. Photo: M. Frye.

What to Do. It bears repeating: Brachymeria are wasps, but they can’t sting people. To manage them, you have to find and remove their food source (that would be fly larvae) and the source’s source (some kind of decaying stuff). Examples include pet poop, old food stuck on the bottom of a garbage can — and dead animals. If that’s is a mouse or rat that dined on rat bait, then inconveniently died inside your wall, think about using snap traps instead. With snap traps, you can remove dead rodents quickly — before the flies do it for you.

Did You Know? Cluster flies are a pest in upstate New York that congregate by the scores or hundreds in attics and other protected spaces. Whereas Brachymeria is a parasite of flies, cluster flies are parasites of earthworms!

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