Fallen, rotting fruit, along with plants infested with aphids and other sap-feeding insects, attract yellow jackets, hornets, paper wasps, bees, and flies that are looking for a late season “sweet fix.”
Figure 1. Flies and wasps on fallen apple (Photo: Lee Townsend, UK)
Management Options
Here are some ways to try to reduce their numbers:
Sanitation
- Maintain high levels of sanitation to make areas less attractive to foraging insects.
- Minimize attractive food sources. Keep food and beverages covered until ready to be eaten.
- Clean up spills and leftovers promptly.
- Locate trash cans and dumpsters away from eating areas, doors, and other high-traffic areas.
- Equip trashcans with fitted, self- closing lids and plastic liners. Empty and clean them frequently.
- Promptly rake and discard decomposing fruits falling from trees.
Avoid contact
- Move away carefully. Foraging insects seldom are aggressive and usually will not sting unless provoked. Resist the temptation to swat or flail at them.
- Drink from covered containers to avoid ingesting insects.
Repellents
- Repellents may keep some insects away. A dilute solution of ammonia and water (approximately 6 ounces of ammonia per gallon of water) sprayed in and around trash cans and sponged onto outdoor tables and food preparation surfaces may help to repel yellowjackets from these areas.
- Use household ammonia, not Clorox (bleach).
Eliminate nests
- Elimination of yellowjackets is best accomplished by locating and destroying their nests. However, with foraging yellowjackets, this is often impractical since the nest (or nests) may be located several hundred yards away.
- If the nest entrance can be located (typically underground in an old rodent burrow, beneath rocks or landscape timbers, or within a stone wall or wall of a building), it may be eliminated by carefully applying a wasp aerosol insecticide into the nest opening.
Allergic Reactions
Wasp, hornet, and yellowjacket stings can be life-threatening to persons who are allergic to their venom. People who develop hives, difficulty breathing or swallowing, wheezing, or similar symptoms of allergic reaction should seek medical attention immediately. Itching, pain, and localized swelling can be somewhat reduced with antihistamines and an ice pack.
Yellowjackets are often considered the most dangerous stinging insects in the United States. They tend to be unpredictable and usually will sting if the nest is disturbed. During late summer and fall, yellowjacket colonies are nearing maturity and huge numbers of workers are out foraging for food for the developing queens. With insect prey (their usual diet) becoming scarce, yellowjackets scavenge for other sources of nutrition, especially sweets (e.g., fruits, ice cream, beer, and soft drinks). The persistent foraging of yellowjackets at picnics and other outdoor activities produces many calls from homeowners and businesses wanting to know what can be done to alleviate the problem.
By Lee Townsend, Extension Entomologist
Kentucky Pest News 