New York State IPM Program

May 5, 2020
by Jody Gangloff-Kaufmann
Comments Off on Asian Giant Hornets – A Concern for New York?

Asian Giant Hornets – A Concern for New York?

A pinned specimen of a large wasp, the Asian giant wasp from a side view.

Asian giant hornet, pinned. Photo by Allan Smith-Pardo, USDA APHIS PPQ, Bugwood.org

By now many Americans reading or watching the news have heard about “murder hornets” from Asia invading the American landscape. It is true that in many parts of East Asia, Japan in particular, a large hornet lives and feasts upon honey bees and other insects. This is the Asian giant hornet (AGH), or Vespa mandarinia, which is a relative of the European hornet (Vespa crabro) that we typically see in North America. The European hornet is an import to America that has naturalized, or become established here as if it was native. The Asian giant hornet has just arrived on North America’s west coast, by unknown means. Residents and beekeepers alike are hoping it doesn’t become naturalized in America.

Pinned specimen of the large black and yellow Asian giant hornet, seen from above.

Asian giant hornet, Photo by Allan Smith-Pardo, USDA APHIS PPQ, Bugwood.org

The Asian giant hornet is the world’s largest, measuring 1.6 to 2 inches long, with a particularly large yellow-orange head. It is a social insect, living in colonies built in soil burrows dug by rodents and other animals. While people may not often see Asian giant hornets, beekeepers will definitely notice their decimated colonies of honey bees. It takes a handful of Asian giant hornets to slaughter an entire honey bee colony, after which hornets feed on the larvae, pupae and honey inside the hive. Japanese honey bees, which are a different species of honey bee than what we raise in North America, can fight back against AGH by surrounding and super-heating the wasp in a ball of bee bodies. Our European honey bees also have this defense behavior, but it is unknown how they would fare with this kind of predation. If AGH becomes established in the US and Canada, the greatest threat will be to beekeepers and their honey bees.

The hazard to humans posed by the stings of AGH is real. The venom is toxic and with their long stingers, AGH can inject more venom into a wound than most other stinging insects. Stings lead to intense pain and swelling, and can induce renal failure and anaphylaxis. Multiple stings can be deadly. But, these hornets do not come after humans and left alone, they mind their own business. The efforts to eradicate AGH from Washington State and Canada will be a priority aimed at avoiding their permanent establishment in the US. Unlike claims in some media outlets, it will likely take many years for this wasp to spread across the country on its own if we fail to eradicate it. Beekeepers will be on the front lines of detection.

*** June 2020 UPDATE – A dead queen Asian giant hornet was discovered this spring on a road near Custer, WA, which is close to the western Canada border. This indicates that queens produced by at least one colony in the Fall of 2019 overwintered and emerged. To date (6/3/20) no other detections have been reported.

*** August 2020 UPDATE

In 2020, both Washington and Canada have had new confirmed sightings of the Asian giant hornet. In addition to earlier reports, one queen, one worker and another unspecified wasp have been reported. This means we are not done with Asian giant hornets yet! Finding a queen wasp in May suggests that they survived winter in the Pacific Northwest. As colonies of these and related wasps grow in size through the end of summer, there may be more findings to report. Stay Tuned!

There are several species of wasps in the US that are very commonly confused with AGH and often killed unnecessarily:

Cicada KillerSphecius speciosus – a large, native, solitary wasp, does not readily sting or act aggressive toward humans, hunts cicadas, exclusively, digs burrows in the soil where eggs are laid upon the body of paralyzed cicadas. Common in suburban areas.

A cicada killer wasp rests on a green leaf.

Cicada killer wasp, photo by Nancy Hinckle, bugwood.org

 

European HornetVespa crabro – an introduced social species, colonies started by a single queen, colony builds and expands a tan paper ball nest typically in hollow trees and abandoned barns and structures. More common in rural areas. Not aggressive unless harassed.

Pinned specimen of European hornet seen from above

European hornet pinned specimen, photo by Allan Smith-Pardo, USDA APHIS PPQ, Bugwood.org

Pinned specimen of European hornet seen from the side

European hornet pinned specimen, photo by Allan Smith-Pardo, USDA APHIS PPQ, Bugwood.org

 

 

 

 

 

 

 

 

 

 

Baldfaced hornetDolichovespula maculata – Large black-and-white wasp, not a true hornet, colonies started by a single queen, nest is a grey paper ball usually high in trees or on the side of structures. Not aggressive unless harassed.

A black and white baldfaced hornet on a white background

A baldfaced hornet resting, photo by Johnny N Dell, bugwood.org

Yellowjackets (many species) – Vespula sp. – Small yellow-and-black wasps that nest in large colonies in soil and other man-made cavities. Can be aggressive, especially in early fall.

A yellow and black yellowjacket pinned in a collection.

A “ground hornet” or “widow yellowjacket, photo by J.L. Gangloff-Kaufmann

Paper waspsPolistes sp. – Slightly longer than yellowjackets, various colors, long legs, umbrella comb nest with a few to a few dozen wasps. Not aggressive unless harassed.

A black and yellow European paper wasp sits on a paper nest.

A European paper wasp sits on a paper comb nest. Photo by David Cappaert, bugwood.org

 

The Bottom Line: A few Asian giant hornets were discovered in Washington State in 2019. The greatest threat is to honey bees and beekeepers. Efforts to eradicate this wasp are underway. New York does not have Asian giant wasps and hopefully won’t anytime soon.

Residents of the west coast should keep an eye out for Asian giant hornets and residents of Washington State are strongly encouraged to submit reports of sightings to the Washington State Department of Agriculture. If you live in New York and have questions about wasps or any stinging insects, you can contact NYSIPM or your local Cornell Cooperative Extension office for advice or to submit samples for identification.

 

December 8, 2017
by Mary M. Woodsen
Comments Off on Wasps in winter? the IPM do-nothing approach

Wasps in winter? the IPM do-nothing approach

You might live in a row house, an apartment house, a single-family dwelling. You might have a carport or outbuildings. You might be buttoning up a concession stand for the winter and moving the picnic benches under cover for the winter.

And then … you see it. Feel it. A wasp or hornet nest, up in the corner of a window jamb or down under a bench. It might even be in a porch light fixture or a parking meter. It might feel like dried mud. Vaguely resemble a chunk of honeycomb, minus the honey. Look like a football (more or less), built of layer upon layer of flaky gray papery stuff.

At least that gray papery stuff didn’t effect reading the meter. Photo Way Out In The Margi

You don’t see any wasps flying in or out. But just to be sure, you get the wasp spray and douse that nest but good. And hope you killed them all, because the last thing you want is wasps knocking at the door this year or next.

But… nobody’s home. It’s not summer anymore. The old queen has died. A newly fertilized queen, replete with eggs, is doing the insect equivalent of hibernation and taken refuge beneath a piece of bark somewhere.

And the rest of the hive? Each member has died a solitary death. Not one is holed up in the nest, waiting to help the new queen clean house, make necessary repairs, and set up shop come spring. Even knowing this, maybe you’re inspired to knock down the hive and stomp on it, just to be sure. Besides, you don’t want wasps nesting under the picnic benches ever again.

Knocking the nest down is all well and good, but it’s rare that a queen would repopulate it anyway. She wants a fresh start. If come spring you see the occasional wasp hanging out on an old hive, know that it’s gathering material for new digs somewhere else. If you’re a paper wasp, for instance, it’s easier to chew that old nest into a mushy pulp for brand new paper than to strip wood from a twig and start from scratch.

A summer home made of mud, off to a good start. Photo Harper College.

Yes, it’s lucky no one handled that nest under the picnic bench or fire-escape railing or any of a hundred other places that nest might have been.

But should you see some wasps next spring and suddenly this story comes to mind, take a look around you. See any signs of tiny new nests taking shape? Are they high under an eave and far from anyplace you could get to with ease? Or is one right next to the entryway to your home? We’ll have a brand-new post for you with brand-new info on wasps, their nests, and what to do about them.

Can’t wait? Go here.

April 4, 2013
by Mary M. Woodsen
Comments Off on Don’t bee fooled

Don’t bee fooled

April can fool you all month long. Even if your pest-prevention responsibilities lie mostly indoors where frost and rain rarely intrude — a school, an office building, a museum, your home — April has some tricks up her sleeve. Those perimeter  pests, for example: wasps, bees, ants, termites. For many species of wasps and bees, queens are the only ones that survive the winter, so most likely you won’t see them making their solitary way in early spring. Take yellowjackets, paper wasps, and hornets. They’re out there scouting for nest sites — which means you should be scouting for them.

 

this starter nest is still small

Scope out entryways, porticos, eaves, and attics for small starter nests — it’s far easier to deal with a queen and a half-dozen workers now than a queen and 5,000 workers later. When you see a nest, knock it down with a broomstick, the spray nozzle on a hose, or even your kid’s Super Soaker. Then step on it. If using the broomstick, best done early on chilly mornings — wasps can’t move fast when it’s cool outside.

 

About yellowjackets — they’re really aggressive in defense of their nests. Not all species nest where you can see them. Some go underground — nesting in abandoned rodent burrows, for instance. Others find sneaky little holes leading into walls or attics. Get professional help — and never swat a yellowjacket (or any other wasp) — it releases alarm pheromones that call its kin to the scene. In the melee that follows you’re likely to get stung way more than you’d like.

 

Got bumblebees buzzing around your house? Most likely they’re carpenter bees, actually. Bumblebees look fuzzy; carpenter bees have shiny black bellies. Some are all-black.

 

Watch as they crawl in and out of their perfectly round holes — these bees are nature’s power drill. Though males will dive-bomb you if you move quickly, don’t be fooled (or frightened!): they can’t sting. Females (less often seen) can sting — but only if you work hard to provoke them. Though new nests are small, carpenter bees can do serious damage as subsequent generations bore deeper into wood to rear their young in turn. How to cope? Start here.

 

Worried you’ve got termites? They might be ants instead. And both termites and ants can swarm on warm spring days — maybe making you think you’ve got some kind of weird bee instead. But those wings are temporary.

 

Here’s how to tell termites and ants apart. Termites seem to have just two body parts: rounded heads with straight antennas and cigar-shaped bodies. Ants, au contraire, have three distinct body parts and (more distinctly yet) narrow-waisted hourglass figures. Note their bent antennae, too. Most ants are an annoyance and no more … but carpenter ants can remodel your home — while termites can demolish it. What to do? Begin here: Carpenter ants. Termites.

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