Refine Your Search

all resources on the CAFE website

Refine Your Search

all resources on the CAFE website

Yellow Jackets

Printer-friendly version

Individuals should exercise all reasonable measures to avoid contact with yellow jackets (Vespula species of wasp) towards the end of August through September. Not only is their population at peak levels, but the insects are a bit testy as they protect their nests. For most of the year they are considered beneficial in that they feed on caterpillars and nuisance flies. However, in late summer they change their diet from these high protein foods to those high in sugar, which explains why they are attracted to over-ripe fruit, sugary beverages, and greasy foods.

Yellow jackets build their papery nests in the ground, in stone walls, in shrubs and trees, in tree trunks and stumps, among piles of stone, wood or lumber stacked outdoors, and in the walls and eaves of buildings. They are also frequently found around water sources such as swimming pools or puddles near faucets.

Anyone working outdoors should constantly be on the lookout for these yellow and black banded wasps. Unlike a honey bee, a yellow jacket can sting repeatedly. Many people, some unknowingly, are allergic to the venom released via the hollow stinger. Reactions to stings range from severe swelling to death. Persons who know they are allergic to yellow jacket stings should consult their physician for information on first-aid treatment - e.g. epinephrine kits - to be used in the event of a sting.

When working outdoors:

  • wear light colored clothing since yellow jackets are attracted to brightly colored clothing and to dark clothing.
  • do not wear fragrances i.e. after-shave lotions, perfumes, hair products, etc, as these attract the wasps.
  • keep a lid or cover on sweet beverages and other foods.
  • check work areas for nests. Vibrations from equipment used outdoors is enough to stir the wrath of yellow jackets.
  • have available a can of wasp and hornet spray (aerosols containing pyrethrin, rotenone and pyrenone are recommended) to apply to nests that are found near work areas.
  • if a nest is disturbed, walk away slowly (rapid movements result in aggressive responses by yellow jackets) keeping your face covered with your hands.

Written by: Robert Childs
Revised: 10/2011

Topics: 
Commercial Horticulture
Commercial Horticulture topics: 
Insects and Mites