paper wasp | Gardening in the Panhandle

Watch for Stinging Insects

by Mark Tancig | Sep 16, 2019

Paper wasps can hide among vegetation and surprise gardeners. Credit: UF/IFAS

As summer comes to a close, many gardeners are getting their landscapes back in shape after the long, hot summer months. There are likely some large weeds and/or vines that have taken over areas where they are not wanted. As you begin to hack these back, it is wise to be on the lookout for wasps and yellow jackets. These stinging insects pack a punch and are particularly active this time of year.

Wasps and yellow jackets are closely related in the insect family Vespidae. These are social insects, similar to ants and bees, that have a division of labor with a queen and workers (both female) carrying out specific tasks for the colony. Males arise from unfertilized eggs and are only needed for reproductive purposes. Once they mate with a female from another nest, they die. Once the fertilized females emerge in late fall, they will overwinter under the bark of a log, or other safe habitat, until spring, when they start a new colony. Unlike bees, who die after a single sting, wasps, yellowjackets, and hornets can sting multiple times. Yellowjackets and hornets even emit an alarm pheromone that causes other members of the nest to aggressively defend the colony.

While there are many different species of wasp in Florida, including the paper, red, mason, potter, and mud dauber wasps, the paper and red wasps (Polistes spp.) are the ones that tend to be most aggressive when provoked and cause a harmful sting. Their nests are often found under house eaves or hidden in amongst shrubbery. These nests hidden in vegetation are the ones that gardeners typically run into when trimming or weeding.

There are three species of yellowjacket in Florida, including the eastern yellowjacket (Vespula maculifrons), southern yellowjacket (Vespula squamosa), and baldfaced hornet (Dolichovespula maculata). All three can be aggressive and sting humans, especially if they feel threatened, such as when pruning or working over or near a colony. Yellowjackets build extensive colonies underground, though can also build colonies in hay, palm fronds, and other loose debris aboveground. These underground colonies usually have a single entrance but can also have multiple entrance holes. Hornets build aerial colonies. Gardeners are most likely to have run-ins with yellowjackets since hornet nests are typically up in trees and more obvious than an underground yellowjacket colony.

Southern yellowjackets create underground colonies that can hold over 2,000 yellowjackets. Credit: UF/IFAS

While these insects can be a major pain, figuratively and literally, they actually do help out us gardeners. The main food source of wasps, yellowjackets, and hornets are caterpillars and beetle larvae, which are often garden pests. They are also native pollinators. Therefore, it’s best that we accept some in the landscape, manage colonies in high-traffic areas, and prevent encounters with them. To reduce your chance of weeding right into a wasp nest, take a stick and knock around the vegetation to see if any are hiding in the brush before getting started. Be ready to run. Yellowjackets are harder to avoid as they are stealthy in their underground bunkers.

When it comes time to remove these insects from near a structure or heavily trafficked area, you may want to consider hiring a professional pest control company. Wasps can be managed by most homeowners with a broom (if the nest is small and/or relatively inactive) or aerosol insecticides specifically formulated for wasp control. Yellowjackets and hornets are trickier to deal with and should be approached very cautiously. Spraying aerosols into a yellowjacket entrance hole is dangerous and may not be very effective as some colonies can be up to a foot wide and contain over 2,000 yellowjackets. Any attempts to control wasps, yellowjackets, and hornets should be done in the evening when they are less active and with appropriate clothing that covers the skin.

Yellowjackets are pollinators and eat caterpillar pests! Credit: Whitney Crenshaw, Colorado State University, Bugwood.org

For more information on wasps, yellowjackets, hornets, and other stinging insects, see the Biting and Stinging Insects section of the UF/IFAS EDIS site (https://edis.ifas.ufl.edu/topic_biting_and_stinging_pests) or contact your local Extension Office.

Wasps Have a Purpose

by Larry Williams | Aug 4, 2014

Mud dauber, Photo Credit: UF/IFAS Extension

Paper wasp, Photo Credit: UF/IFAS Extension

I respect the fact that wasps can sting when threatened or disturbed. But I also respect the fact that they are beneficial.

Every time I’ve been stung by wasps, I either accidentally disturbed a nest that I didn’t know was there or I intentionally disturbed the nest and paid the price.

Paper wasps are common in Florida. They frequently construct and attach their paper-like nests to building eaves or the ceilings of porches. The adults seek out caterpillars, which they sting and paralyze. They then take the caterpillars back to their nest and place them in individual cells as food for the developing larvae.

I’ve witnessed the paper wasp as it stings and carries away a caterpillar from my vegetable garden. They are busy insects and are doing us gardeners a favor by reducing the population of caterpillars in our landscapes and gardens.

There are other beneficial wasps in Florida. Mud daubers, for example, build their mud-like nests on the sides of buildings close to human activity.

The mud dauber is not as aggressive as the paper wasp. It rarely stings people. It stings and paralyzes spiders. The mud dauber lays an egg on each paralyzed spider and seals it inside a chamber in its earthen nest. Upon hatching, the wasp larva feeds on the body of the spider. An emergence hole is made as the young wasp leaves the mud nest.

It may not be wise to tolerate all wasp species living in close proximity to your home. Even though yellow jackets, a type of wasp, could be considered beneficial, they are too aggressive and too likely to repeatedly sting to have as close neighbors. I also would be concerned with any type of wasp or bee nest existing in close proximity to individuals with a known allergy to insect stings.

Just because an insect has the ability to sting, it’s not all bad. Wasps can serve a beneficial purpose. But you’ll have to decide for yourself how close to you they can build their nests. The front porch may be too close.