When we think of beneficial insects that inhabit the garden, the paper wasp is not very likely to be a critter that would first come to mind to most home gardeners. In fact, it is not likely to make any lists!
Adult paper wasps are efficient predators, mostly of caterpillars. They carry them back to the nest and feed them to the developing larvae. They will collect large numbers of caterpillars from the area around the nest during the course of a season. Adult wasps typically prey on a wide variety of caterpillars including corn earworms, armyworms, loopers, and hornworms. Adult wasps also utilize beetle larvae and flies as food for their young..
Adult paper wasps primarily feed on nectar or other sugary solutions such as honeydew and the juices of ripe fruits. Adults also feed on bits of caterpillars or flies that are caught and partially chewed before presenting to their young.
It is their painful stinging ability that causes alarm and fear. Unless the threat of stings and nest location presents a hazard around the home, it is often best to wait for Mother Nature to kill these annual colonies with the onset of cool weather in late November and December.
Paper wasps are ¾ to 1 inch long. Their colors vary with different species. They should not be confused with hornets or yellow jackets. The paper wasp is sometimes called the “umbrella wasp” because their nests consist of a single exposed comb suspended by a narrow stalk. The adult wasps typically prey on caterpillars, flies, crickets and other pests. However, they will sting to defend their nests.
The female wasp will feed chewed up caterpillars and other prey to her young wasp larvae until they seal their cells in the nest and become pupae. Whenever enough female worker wasps have emerged, they take over the duties of food collection and nest construction and defense, while the queen remains with the nest producing more offspring.
During the spring and summer, the nest may enlarge to 6-to-8 inches in diameter with several dozen wasps. In early fall, the colony begins to produce males and special reproductive female wasps. These reproductive females, which constitute next year’s queens, mate with males and soon leave the nest in search of protected spots in which they spend the winter. The remaining worker wasps eventually die and the nest becomes vacant. Paper wasps will not reuse their nests the next year.
Wasps chew with their mouthparts. Occasionally parts are chewed from live plant stems which can cause some plant damage. Also, paper wasps chew wood fiber from posts and other exposed wood.
Remember, paper wasps are actually beneficial insects because they prey on other insects that we consider pests of the shrubs and flowers around our homes. If a nest is located where it is out of the way and not likely to be disturbed, homeowners should consider leaving it alone. If, however, a nest is located in a “high traffic” area such as along walks or near doorways or in areas where children play, control is justified to reduce the threat of being stung. One control option is the use of insecticides formulated in pressurized containers that emit a narrow stream of spray from a distance of 15-to-20 feet from a nest.
If a person is ever stung and experiences difficulty breathing, they are having an allergic reaction and should seek emergency medical treatment immediately. As Master Gardener volunteers, we must always caution individuals who are especially sensitive to stings to consider obtaining the services of a reputable, licensed, professional pest control operator who has the experience, equipment and most effective insecticides to get the best job done.
Beneficials in the Garden & Landscape is an Earth-KindTM program coordinated through Extension Horticulture at Texas A&M University. Earth-Kind uses research-proven techniques to provide maximum gardening and landscape enjoyment while preserving and protecting our environment.
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