wasps

Bees have such a great reputation. They are the face of pollinator conservation and we know how valuable they are in our food system. But what about wasps? Where is the love? Wasps are also fascinating pollinators. Did you know that wasps are the main pollinators of figs?

Your garden is full of beneficial wasps. They dine on the pollen and nectar provided in pollinator gardens and are valuable pollinators. They also assist in controlling grubs, caterpillars, and crickets. Wasps provide important garden services!

Sadly, wasps seem to have a bad reputation. They are seen as aggressive stingers. This is not necessarily true. Most wasps are nonaggressive and will only sting when they are grabbed or threatened. These insects are beautiful and fun to watch.

One example of a wasp you may see in your garden this summer is the four toothed mason wasp. This wasp visits all types of flowers. They are cavity nesters, laying eggs in small cavities already created by another wasp or bee. They also use holes in twigs or hollow flower stems. If you have a native bee home in your garden you probably have a mason wasp or two using those homes.

The female wasp hunts for soft-bodied caterpillars to carry back to the nest. She will lay an egg and leave a stunned caterpillar next to that egg. As the egg hatches, the emerging wasp larvae will consume the caterpillar. This is a great service to your garden as you battle caterpillars that eat your food crops.

However, mason wasps do not differentiate between pest caterpillars and the caterpillars of beloved butterflies. Gardeners do have a bit of control here. Plant milkweed, parsley and other butterfly larval plants away from plants that wasps frequently visit such as mountain mint. Otherwise, think of your garden as a whole ecospace and thank the wasps for their help in controlling the pests!

Another valuable wasp is the Scoliid wasp (Scolia dubia). This wasp lives in the soil. The adults can be seen on several flowering plants eating pollen and nectar. The females lay their eggs in the ground. At egg-laying time she will fly just above the ground looking for grubs. When one unlucky grub is spotted, the wasp paralyzes it by stinging. This grub is left with her eggs for the emerging larva to consume. Grub control is another valuable service the wasps provide.

As wasps begin to appear in your garden take some time to appreciate their beauty and the services they provide. Consider becoming more involved with pollinators by participating in the Great Georgia Pollinator Census in August (https://GGaPC.org).

This information is taken from the publication Management of Insect Pests in and Around the Home by Daniel R. Suiter, Brian T. Forschler, Lisa M. Ames and E. Richard Hoebeke.

Hornets (Vespidae: Vespa spp.)

The European hornet, Vespa crabro, was accidentally introduced into North America about the middle of the 19th century. It is a large eusocial wasp with the wings reddish orange and the petiolate abdomen brown and yellow striped. There are no native hornets in the U.S.

Habits: European hornets build large, above-ground nests, usually in trees. Similar to yellow jackets and paper wasps, European hornets build a new nest each year. Each Fall all hornets die, with the exception of several queens, which overwinter. The following Spring these overwintered, mated queens initiate the construction of a new nest. European hornets are attracted to lights at night. They are not attracted to human foods and food wastes, as are yellow jackets, but they can damage fruits, such as apples, while the fruit is still on the tree.

Interventions: If European hornets are found around the house at night, because these wasps will forage after dark and are attracted to lights, examine and change the lighting regime. Do not attempt to remove or treat a nest; call a pest management professional to remove nests near areas of human habitation or activity. For more information see University of Georgia Extension circular #782, Stinging and Biting Pests, at caes.uga.edu/publications.

Might Be Confused With: cicada killers, yellow jackets.

Mud Daubers (Sphecidae and Crabronidae: many species)

Long, slender, solitary wasps 1 to 1.5 inches, with long, slender waists. Commonly glossy black or blue, some species with yellow highlights.

Habits: Builds series of four- to six-inch long vertical mud tubes on walls in areas protected from rain and adverse weather. Commonly found under eaves, decks, etc. Each tube comprised of individual cells housing a single larva and spider prey that wasp larvae feed on.

Interventions: Knock down dry mud nests with a broom and wash mud from wall with soap and water. For more information see University of Georgia Extension circular #782, Stinging and Biting Pests, at www.caes.uga.edu/publications.

Might Be Confused With: paper wasps, potter wasps.

Paper wasps (Vespidae: Polistes spp.)

Large (1 inch), aggressive wasps when at their nest. Various species, but all build paper-like, multi-celled, inverted umbrella nests under rain- and wind-protected eaves where wasps can enter and exit easily.

Habits: Each Fall all wasps die, with the exception of several queens, which overwinter in an inactive form in a well-protected, secluded environment such as under and in fallen logs and other ground debris. The following Spring, queens initiate and build a small paper nest where they lay eggs. Paper wasps build a new nest each year. Colonies grow and reach peak size in the Fall, at which time the cycle repeats. Like other social bees and wasps, paper wasps are aggressive when protecting their nest, and may inflict a painful sting in its defense. Adult wasps are excellent predators in vegetable gardens, and are more docile when not protecting their nest.

Interventions: If nests are out of the way, leave wasps alone as they are highly beneficial predators. If desired, spray nest and wasps directly with an aerosol jet spray, or early in the year, before the nest contains too many adult wasps consider knocking down the nest with a long stick but be prepared – and able – to quickly flee the area as the nest is dislodged. Make certain no one in the area is allergic to wasp venom (stings). For more information see University of Georgia Extension circular #782, Stinging and Biting Pests, at www.caes.uga.edu/publications.

Might Be Confused With: mud daubers.

Potter wasps (Vespidae, but sometimes recognized as Eumenidae: many species)

Also referred to as mason wasps. Common species dark blue or black with yellow or white highlights on abdomen and/or thorax. Solitary. Common species 3/4 to 1inch. Strongly sclerotized.

Habits: This wasp builds characteristic, oval-shaped (1/2 to 5/8 inch diameter) nests that appear pot-like with a knob-like handle. Pots are ornate and constructed of mud, as if built by a mason.

Interventions: Knock down ‘mud pot’ nests with a broom and wash mud from wall with soap and water.

Might Be Confused With: mud daubers.

For more information see these UGA publications:

Management of Pest Insects in and Around the Home

Stinging and Biting Pests

Garden Wasps – Where is the Love?

Wasps and hornets looking for a place to call home!