Wasps

Wasps can transform a summer picnic into a mad scramble for safety, especially for those who are allergic. But wasps aren’t all bad. Really, they’re not!

Yellow jacket (Bombman356) CC BY-SA 3.0

Cousin to bees, ants, and sawflies, wasps come in an astounding variety of good, bad, and indifferent garden insects. There are over 100,000 different types of wasps (Vespidae) around the world and only some of them will hurt you. But, ass anyone who has ever been stung knows, once is more than enough!

Wasp description

Wasps tend to have relatively long, slender bodies with the telltale wasp-waist, between the thorax and abdomen. Most wasps have two pairs of wings, though some are wingless. The variety is really pretty amazing. It’s a shame they are so painful. Did you know that wasps dangle their legs as they fly?

Why the sting?

Male wasps do not sting. Much like carpenter bees, it is the job of the female to protect and defend. As she hunts down food for herself and her colony, she will protect herself, her family, and her food sources with extreme prejudice. The stinger is actually a modified egg-laying organ. A wasp can sting multiple times and it really hurts. As a child, I would get them caught in my long hair. It was terrifying at the time! Swarms can be deadly.

Wasp lifecycle

There are social wasps and there are solitary wasps. Social wasps live in colonies, led by a queen. Some wasps burrow in the ground, some use mud to create apartment complexes, while others build paper nests. In these nests, the queen begins laying eggs. These eggs hatch into female workers. In late summer, some eggs hatch into male drones, whose sole purpose (in their very short lives) is to mate with the queen, after which, they die. Most social wasps are predators, killing many garden pests each year. As resources become scarce and colony size grows, these wasps become scavengers. Those are the ones that cause the most problems for us.

Yellow jackets

Yellow jackets are predatory social wasps. They are black with yellow or white markings. Despite their painful sting, these are beneficial insects in the garden. At 1/2 and inch long, these wasps spend most of their time hunting insects, drinking nectar, and building nests in trees, burrows, and against your house. The insects they collect are often garden pests. Adult yellow jackets bring the insects back to the colony and feed them to the larval generation. Those larvae then excrete a sugary concoction that is eaten by the adult yellow jackets. This is called trophallaxis. 

Yellow jacket nest (HornetBoy1970) CC BY-SA 3.0

You may be able to identify a yellow jacket by its tendency to fly side-to-side as it prepares to land. The colony consists of a queen, workers, and drones. Only the queen lives through the winter.

​Hornets

Hornets are a subspecies of wasp that are particularly aggressive. Hornets tend to have wider heads and more rounded abdomens than other wasps. Hornets can both sting and bite. There is a hornet in Japan, the Asian giant hornet, that has a stinger that is one-quarter of an inch long and it kills 30 to 40 people in Japan each year. Yikes! Scientists say that hornet stings are more painful than wasp stings, because they contain more venom (acetylcholine). I think they all hurt and are worth avoiding.

Hornet eating a honey bee (Richard Bartz) CC BY-SA 2.5

Paper wasps

Tiny, umbrella-shaped paper nests are your first clue that paper wasps have arrived. Before you get rid of that papery umbrella, you might be happy to learn that paper wasps feed on beetle larvae, caterpillars, and flies, along with nectar. Paper wasps are effective pollinators. There are over 300 different types of paper wasps, but they all chew wood fiber and transform it into intricate papery nests. There are both solitary and social paper wasps. Paper wasps are not very aggressive, unless threatened. ​​

Paper wasp (Alvesgaspar) CC BY-SA 3.0

Mud dauber (Hlgu1) CC BY-SA 3.0

Mud daubers

Mud daubers’ distinctive nest makes them easy to identify when close to home. There are several different types of mud daubers. Generally speaking, mud daubers are not aggressive, unless they feel their colony is threatened. Like yellow jackets, mud daubers are predators. Spiders are their favorite food. An adult mud dauber will sting a spider, paralyzing it, and then transport it to the colony where the spider will be injected with an egg and sealed into the cell, becoming a baby mud dauber’s first meal. Apparently, mud daubers are very particular about the types and sizes of spiders they prefer.

Beneficial wasps

Mud dauber nest (Pollinator) CC BY-SA 3.0

Adult wasps mostly eat plant material, especially sweet nectar, sap, pollen, and rotting fruits. As they fly from flower to flower, collecting nectar and pollen, wasps also pollinate your crops.

There are even wasps, called chalcids, that have evolved specifically to pollinate figs. No wasps, no fig bars!

Ichneumon wasp (Vengolis) CC BY-SA 3.0

Chalcid wasp (Hansson C, Shevtsova E) CC BY 3.0

Wasps are frequently released in agricultural fields as natural ‘biocontrols' of many common pests. The adult wasps lay their eggs on or in these pest insects. As the eggs hatch, they devour their host. (Gruesome, right? It’s brutal world out there.) Ichneumon wasps are commonly used in this form of integrated pest management (IPM).

​Some wasps, such as the braconids and trichogramma wasps, are so tiny that you’ll never see them, but they are extremely helpful in your garden and landscape. These beneficials parasitize hornworms, apple maggots, orange tortrix moths, mealybugs, aphids, orangeworms, armored scale, armyworms, artichoke plume moths, and many other pests. Some species of wasp are believed to carry certain yeasts to grapes used in winemaking!

Braconid wasp (Richard Bartz) CC BY-SA 2.5

Preventing stings

In the case of wasp stings, an ounce of prevention is, well, you know! Use these tips to prevent getting stung in the first place:

• do not wear perfume, cologne, or scented soaps when in wasp territory
• avoid wearing brightly colored or patterned clothing
• do not swat at a wasp
• avoid going barefoot, especially on clover and other flowering ground covers
• be alert to your surroundings
• stay calm
• if barbecuing near yellowjackets, simply place a piece of meat someplace nearby, to lure the pests away safely

Sting management

If you are unlucky enough to get stung by a wasp, you can reduce the discomfort with these tips:

• wash the area with soap and water 
• take or apply an antihistamine
• calamine lotion or hydrocortisone cream can be applied
• a paste of baking soda and water can be applied
• do not rub or scratch the area
• apply a cold compress

If an allergic reaction occurs, get medical attention IMMEDIATELY.

Wasps with brighter and darker colors tend to be more venomous, so use those colors as a warning.

Did you know that the golden paper wasp (Polistes fuscatus) is the only insect on Earth that has been shown to use facial recognition to identify individuals? Maybe that’s why some people get stung more than others.