Clark Talks Turf: Yellowjackets and garbage cans

By |  September 1, 2017 0 Comments

Timothy Gibb, Ph.D., is an entomologist at Purdue University. Tim has worked on numerous insect problems throughout his career, including turfgrass pests and insects that can impact human health. You may reach Tim at gibbs@purdue.edu for more information.

Q: Is it wasps or bees that hover around garbage cans on the golf course in late summer and early fall?

Yellowjackets (yellow and black stinging wasps), are most commonly found around garbage cans on golf courses in late summer, although a few bees may be present as well. Yellowjackets are the most prevalent, annoying and dangerous.

Q: What is the general life cycle of yellowjackets?

Yellowjackets are social insects that live in colonies with a queen and have a one-year life cycle. The queen leaves the nest and mates in late fall, passes the winter in a protected site and lays eggs in the spring, starting a new colony each year. The queen always locates her new nest in a protected site such as a cavity below ground, in a tree or inside a structure.

In early spring, the queen nurtures the young yellowjackets, but as the colony increases in number, workers assume the role of caring for, feeding and protecting the colony. The queen’s primary function is to lay eggs. All the worker wasps in the colony are female, are capable of stinging and can sting repeatedly. They aggressively protect the nest and colony. The population of the colony may increase rapidly to 5,000 or more yellowjackets by late summer.

In extreme circumstances, a person who unwittingly disturbs the nest can be stung many times, and if that person happens to be hyper-sensitive to the venom, they may go into anaphylactic shock and possibly die.

On the other hand, in nature, yellowjackets are quite beneficial. They only become a problem when encountering people.

Q: What attracts yellowjackets to the garbage cans?

Sugars and proteins attract yellowjackets. Residue from beer, soda pop, sports drinks, fruit, sandwiches, hot dogs and hamburgers accumulate in garbage cans. Once one yellowjacket finds a food source it will communicate that location to the rest of the workers in the colony. Soon the garbage can will be swarming with
yellowjackets.

Q: What can superintendents do to decrease the number of yellowjackets around the garbage cans?

First, understand that spraying pesticides is not the answer. Yellowjackets are the safety concern, not bees. We need to protect bees for their ability to pollinate plants. In late summer, remind golfers to be aware of yellowjackets.

Good sanitation practices constitute the best prevention on a golf course. Using plastic garbage can liners and removing trash daily will help. Wash garbage cans regularly to remove any food or drink residue. Garbage cans with self-closing lids may also help.

During times of high yellowjacket activity, relocate the garbage cans away from places where golfers congregate. Garbage cans placed on the tees will put golfers close to the yellowjackets, where bad things might happen. If possible, place the garbage can somewhere between a green and the next tee to minimize contact between golfers and yellowjackets.

The same principle holds true for garbage cans and dumpsters around the clubhouse. Relocate them where there is lower potential for people/yellowjacket
encounters.

Q: What can superintendents do to decrease the population of yellowjackets around the golf course?

To reduce yellowjacket populations and to prevent accidental encounters, eradicate all yellowjacket nests on the golf course where contact with golfers is likely. (There is no need to search for or control yellowjacket colonies that are not in areas frequented by people). Sevin (carbaryl) or Ficam (bendiocarb), as well as various pyrethroid insecticides, are effective for controlling yellowjacket nests. Use dust formulations and apply at night when wasps are in their nest and are less active. There is no need to plug the entry hole.

There are no effective traps to eliminate yellowjackets.

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