Season of the Sting

Wandering around the Montana outdoors, whether on foot, horse, or bike is going to bring us into contact with our stinging insect neighbors, specifically bees and wasps. These include the bumblebees, sweat bees, mud-daubers, thread-waisted wasps, honey bees, paper wasps, bald-faced hornets, and yellowjackets. During the late summer and early fall yellowjackets become very active and aggressive in their search for food, increasing the likelihood of us getting stung. At best, such encounters are painful, at worst they can be life-threatening.

Photo: Pest Control Plus: https://www.pestcontrolplus.biz/

yellow-jackets-information/

Wasps and bees, along with ants, are insects in the order Hymenoptera (“membrane wing”). There are literally hundreds of thousands of known and undiscovered Hymenoptera species. Collectively these insects are beneficial pollinators, predators on other insects, and useful scavengers. These insects may be solitary, living and foraging alone without building nests or be social, living together in nests comprising thousands of workers and one queen, organized in a distinct caste system to cooperatively rear young and defend the nest.

The words wasp, hornet and yellowjacket are commonly used interchangeably, but this both confusing and inaccurate. The name “yellowjacket” properly applies to medium-sized black-and-yellow wasp species in the Vespula and Dolichovespula genus, such as the Western Yellowjacket (Vespula pensylvania). “Hornet” is properly applied to larger black-and-ivory species in the Dolichovespula genus, such as the Bald-faced Hornet (Dolichovespula maculate). The other common wasp is the paper wasp, such as the European Paper Wasp (Poliistes dominulus), whose appearance is similar to that of the yellowjacket but slimmer and more elongate. Humans commonly tangle with yellowjackets, hornets, and paper wasps when we inadvertently approach their nest, mistakenly trap them in our clothing, or get between them and their intended food.

Social Insects

The generalized life cycle of social insects is a lesson in evolutionary complexity. In the case of social wasps, young queens emerge from their overwintering sites emerge in the late spring/early summer and begin creating a colony by constructing a new colony. Built for wood fibers chewed from trees, fences, and even cardboard, they construct a small, papery, umbrella-shaped nest underground or in a tree, roof eve, or other site.. Yellowjackets commonly build subterranean nests in abandoned animal burrows, fallen logs, or crevices, while both yellowjackets and bald-faced hornets build aerial nests. After selecting a suitable site, the queen fashions 20 or more hexagon-shaped cells and lays an egg in each. In 2-3 weeks, dependent on temperature, the larva pupates, then emerges as a worker wasp. As their name suggests, these unfertile female “workers” are responsible for finding food, feeding the young, enlarging the nest and defending it. The queen stays in the nest getting fed and laying eggs.

In late summer or early fall, the queen lays a series of unfertilized eggs that grow into drones (fertile males) and fertile females (potential future queens) who remain in the nest, fed by workers until they’re ready to leave the nest in mating flights. Fertile females who have successfully mated with one or more drones overwinter underground or in logs and such to emerge the next year and start the cycle anew. All other members of the colony, including the founding queen, die as winter’s hard freeze arrives.

 Hornets, Yellowjackets, and Paper Wasps

Bald-faced Hornets. Relatively large (3/4”), heavy-bodied, ivory-and-black wasp. Build above-ground paper nests that can be as large as a football. May have leaves and twigs in outer nest wall. Feed on other insects (including yellowjackets) and not commonly a nuisance around human foods. When provoked, their sting is painful due to strength of their venom.

Photo: Bug Hunters Pest Control http://www.bughunterspestcontrol.com/montana-pests.html

Paper Wasps. Similar in overall appearance to yellowjacket but with a slimmer, elongate body, and longer legs that dangle in flight. Build open, down-pointed umbrella-shaped nests with no outer paper covering in protected areas. Feed on soft-bodies, leaf-feeding insects and nectar. Relatively docile but will sting in defense of nest or when found in close contact.

Photo © Derrick Ditchburn/ http://www.dereila.ca/bugs06/page1b.html

Yellowjackets. Medium-sized (1/2” long), black-and-yellow wasp. Nest built above-and below ground, not containing leaves or twigs in outer paper layer. Feed on other insects, carrion, nectar and fruits, and human foods. Most aggressive of the stinging wasps.

Photo: Creative Commons

Uninvited Picnic Guests

Unlike honey bees, yellowjackets do not produce honey or store floral nectar in the nest. They feed primarily on other living insects, killing them by bite or by stinger. As summer progresses, insect prey becomes scarcer, and the nest’s demand for food increases, yellowjackets become more scavengers, seeking out honeydew (the liquid secreted by aphids), fruits, nectar, carrion, and human foods. This scavenging behavior brings yellowjackets into close contact with humans. The incidence humans getting stung increases markedly as the wasps climb on picnic plates and enter open soda cans in search of sugary foods.

While wasps can both bite and sting, it’s the sting we remember. Located at the tip of the abdomen, the sting is a needle-like device that delivers a dose of venom. Only the female worker wasps have stingers, but that is small comfort since they are by far the most numerous and most likely encountered. The stingers of wasps are not barbed (like those of bees), allowing them to sting repeatedly. Wasps sting to kill their insect prey, in defense of their nests, and when otherwise provoked. An interesting evolutionary note is that the sting is a modified egg-laying tube evolved over time into a venom-delivery system. The queen retains the egg-laying ability while the infertile female workers got the sting.

Most of us react to being stung with a string of invectives, moderate-to-intense short-term pain, followed by a localized reaction to the venom consisting of itching, redness and swelling around the sting site. Some 1-3 percent of the human population, however, may experience a systemic (whole-body) reaction that may require emergency medical treatment.

Emergency Medical and First Aid Response

Immediately contact EMS support if the victim:

·         Has known allergic response to insect stings.

·         Cannot breathe easily, tightness in the throat, have difficulty swallowing, feel light-headed.

·         Changes to the skin such as breaking out into hives.

·         Is stung several times, or has been stung in recent days.

·         Is stung inside mouth, or around neck.

First Aid Relief Strategies:

·         Ice compresses to reduce swelling and associated pain.

·         Apply a paste of water and baking soda to sting site.

·         Use vinegar or anti-itch cream to treat itching,

·         Take OTC oral antihistamines and pain medicines.

·         Gently wash sting site with soap and warm water.

Resources

Homeowner Guide to Yellowjackets, Bald-Faced Hornets and Paper Wasps. Edward Bechinski, Frank Merickel, Lyndsie Stoltman, and Hugh Homan. University of Idaho Extension, Bulletin 852. http://extension.uidaho.edu/clearwater/files/2014/11/Homeowner-Guide-to-Yellowjackets-Bald-Faced-Hornets-and-Paper-Wasps.pdf

Montana Bee Identification Guide. Casey Delphia, Kevin O’Neill, and Scott Prajzner. Montana State University. http://www.pollinator.org/PDFs/MontanaBeeGuide-Final.pdf

Social wasps and Bees in the Upper Midwest. Jeff Hahn, Laura Jesse and Patrick Liesch. University of Minnesota Extension. https://www.extension.umn.edu/garden/insects/find/wasp-and-bee-control/

What to Do for Yellow Jacket Stings. Healthline.com @ http://www.healthline.com/health/yellow-jacket-stings#overview1