Wait, Wasps are Good Guys?

Yes, wasps are definitely good guys. Wasps are beneficial insects that feed on other insects, by destroying many harmful bugs that attack our landscape ornamentals and home vegetable gardens. However, they tend not to be very friendly to us, when we encroach on their territory. In other words, we really don’t want them to be close neighbors.

There are five members of the wasp family commonly encountered in Florida. These are hornets (Vespa spp.), yellow jackets (Vespula spp.), paper wasps (Polistes spp.), mud or dirt daubers (Sphecidae spp.), and cicada killers (Specius speciosus). Hornets, yellow jackets, and paper wasps are likely to sting if you go near or disrupt their nests. Mud daubers and cicada killers usually will not sting, unless you touch them.

Photo: Clockwise from top left: Hornet, Yellow Jacket, Paper Wasp, Mud Dauber and Cicada Killer.

Credit: P. G. Koehler and J. L. Castner, UF/IFAS Extension, Department of Entomology and Nematology.

There are parasitoid wasps, such as Tamarixia radiata, that are very beneficial, if you are a citrus grower. This native species is a biological control method for the Asian citrus psyllid, which is the vector for the devastating citrus greening disease. If you are interested in releasing juvenile Tamarixia radiata on your property please visit the Florida Department of Agriculture and Consumer Services website for an application: https://www.fdacs.gov/Divisions-Offices/Plant-Industry/Bureaus-and-Services/Methods-Development-Biological-Control/Biological-Control/Asian-Citrus-Psyllid-Biological-Control/Biological-Control-of-Asian-Citrus-Psyllid-in-Dooryard-Citrus-and-Ornamentals/Tamarixia-Release-Application or call 1-800-435-7352.

So, how do I identify nests? Hornets build football-shaped or pear-like nests usually in trees, away from populated areas, mostly found in the woods. Hornets and yellow jackets seldom live near people. Yellow Jackets build above ground nests, like those of hornets, but more commonly nest in the ground. Paper wasps are frequently found around homes where they construct their honeycomb nests in shrubbery and under eaves. Mud daubers often build their mud-cell nests on the walls and under the eaves of homes. Cicada killers, which are least troublesome of all, nest in the ground. Hornets, yellow jackets, and paper wasps are social insects. They live in colonies, like bees and ants. Mud daubers and cicada killers are solitary wasps.

If wasps do become a nuisance, you can eliminate hornet and yellow jacket nests by calling a certified exterminator of if you are an experienced do-it-yourself home owner, spray the nest opening with a potent wasp and hornet pressurized spray normally found at your local garden center or hardware store.  After treating any of the aboveground nests, leave immediately and wait until the wasps are dead. Then, return, knock down the nests, and burn it. To control mud dauber, scrape down their mud cells, and spray the area with an insecticide like pyrethrum or malathion to discourage re-nesting. To treat underground nests, spray with a pyrethrum or Sevin and seal the opening with soil, to keep the insects from escaping.

The severity of reaction to a wasp sting varies drastically, depending on an individual’s sensitivity to the venom.  At best, a sting will cause painful swelling.  In extreme cases, serious illness, or even death, may result.  If a sting victim has a history of hay fever, asthma, or other allergy or if allergic symptoms develop a physician should be contacted immediately

All types of wasp nest should be approached with caution. The best times to apply insecticides are in the early morning or late evening when most of the wasps are in the nest and least active.

For more information, contact your local county extension office.

Supporting information for this article supplied by retired UF/IFAS Extension Entomologist Dr. Don Short and other information can be found in the UF/IFAS Extension EDIS publication: https://edis.ifas.ufl.edu/pdffiles/IN/IN02100.pdf

For more information on Tamarixia radiata, please visit: https://www.fdacs.gov/Divisions-Offices/Plant-Industry/Bureaus-and-Services/Methods-Development-Biological-Control/Biological-Control/Asian-Citrus-Psyllid-Biological-Control/Biological-Control-of-Asian-Citrus-Psyllid-in-Dooryard-Citrus-and-Ornamentals

UF/IFAS Extension is an Equal Opportunity Institution.