Common Stinging Insects of Colorado

Western Yellowjacket Prairie Yellowjacket Aerial Yellowjacket Baldfaced Hornet Vespula pensylvanica Vespula atropilosa Dolichovespula arenaria Dolichovespula maculata

TOP THINGS TO KNOW

• In Colorado, people are stung most often by the Western yellowjacket or the

European paper wasp. Prairie yellowjacket in a mating ball. Photograph courtesy of Joseph Berger. Aerial yellowjacket nest. Photograph courtesy of Howard Ensign Evans. Baldfaced hornet nest. Western yellowjacket scavenging syrup Western yellowjacket nest entrance at the • Worker honey bees can only sting once. covered corn fritters. base of a brick wall. Their barbed stinger pulls out and

remains behind.

The western yellowjacket is a notorious pest around outdoor • All other stinging insects can sting dining areas and is, by far, the repeatedly. They do not have a barbed most important stinging insect in the western United States. stinger. It is a scavenger that primarily feeds on dead animal material • Colonies of honey bees survive year Prairie yellowjacket. Aerial yellowjacket. Baldfaced hornet collecting honeydew from oak galls. and available sweets. Nests are made of paper but occur round in hives and divide when swarming PREDATOR: OTHER INSECTS PREDATOR: OTHER INSECTS PREDATOR: OTHER INSECTS underground or in cavities near in late spring. the ground and are not visible NESTS: IN CAVITIES ON OR NEAR NESTS: LARGE, PAPER-ENCLOSED NESTS: LARGE, PAPER-ENCLOSED Exposed nest of western yellowjacket. THE GROUND ABOVE GROUND ATTACHES BUILDINGS ABOVE GROUND IN TREES AND SHRUBS Photograph courtesy of Ken Gray/Oregon State unless uncovered. University. • Paper wasps, yellowjackets, bumble bees and the bald faced hornet all produce new nests each year. The old Bumble Bees Honey Bees Golden Polistes European Paper Wasp nest is abandoned at the end of the year. Bombus spp. Apis mellifera Polistes fuscatus Polistes dominula • The first step in an Integrated Pest Management program is to correctly identify the insect.

Interior of a bumble bee colony. Photograph courtesy of Ken Man-made honey bee hives in an apiary. Multiple nests produced by golden polistes. European paper wasp collecting wood fibers Gray/Oregon State University. Photograph courtesy of Joseph Berger. for nest construction. European paper wasps nesting in clothes line pole.

Since its arrival in Colorado ca. 2000 the European paper wasp has become a very common resident of yards/gardens in much of the state. They produce relatively small, single layer paper nests that they Bombus huntii, a common orange marked species of attach under eaves, other Foraging honey bee with full pollen sacs. overhangs or in small above bumble bee. Golden polistes. ground cavities. It is a POLLINATOR POLLINATOR AND SOURCE OF HONEY. PREDATOR: OTHER INSECTS predator of other insects and does not scavenge food. NESTS: FOUND IN SMALL CAVITIES, NESTS: MADE IN LARGE CAVITIES, NESTS: PAPER NESTS LARGER THAN However, the nests are often SUCH AS ABANDONED RODENT OR BIRD EITHER HIVES PROVIDED BY HUMANS THE EUROPEAN PAPER WASP A large European paper wasp nest. hidden and when disturb stings NESTS. NESTS LAST FOR ONLY ONE OR IN SITES SUCH AS HOLLOW TREES. may occur. SEASON. HIVES ARE MAINTAINED YEAR-ROUND.

Author: Dr. Whitney Cranshaw, CSU Design: Genevieve Berry, CSU