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 do not have this defense behavior. 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.

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

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.

 

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.

July 8, 2015
by Joellen Lampman
Comments Off on Get Rid of Carpenter Bees? Yes, Please!

Get Rid of Carpenter Bees? Yes, Please!

Carpenter bees are common spring and summer insects in the eastern United States. They first come to attention when males “buzz” or “dive bomb” people passing by and females are seen excavating holes in wooden structures. Like carpenter ants, carpenter bees do not eat wood, but rather use the substrate for nesting. They are important pollinators, but can become a nuisance pest of structures.

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.
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.

Did You Know…?

  • By the numbers: Carpenter bees are solitary insects that do not form colonies, but many females may nest in the same area.
  • Mock attack: If males feel their nests are threatened, they will aggressively pursue and harass, but they have no stinger.
  • Look-alikes: Both carpenter and bumble bees are black and yellow, but bumble bees have fuzzy abdomens while carpenter bees are smooth.
  • Galleries: On average, galleries are 4 – 6”, but tunnels can extend up to 10 feet long.
  • Collateral Damage: In addition to the structural damage caused by carpenter bee tunneling, empty galleries can invite secondary pests such as beetles, moths and scavengers, and even fungal rot when moisture enters openings.

Integrated pest management can help to prevent carpenter bees from redecorating your home. See Get Rid of Carpenter Bees? Yes, Please! fact sheet for more information on carpenter bees and how to manage them.

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