Yellowjacket

Face of a Southern Yellowjacket Queen (Vespula squamosa)

Vespula vulgaris SEM Sting 01

Vespula 0078

Yellowjacket refers to several species of wasps in the genera Vespula and Dolichovespula. They are known for their distinctive black and yellow coloration and are often mistaken for bees. Unlike bees, yellowjackets are more aggressive, especially when their nests are disturbed. They play a crucial role in the ecosystem as predators of pest insects and as pollinators.

Description

Yellowjackets are medium-sized wasps with a black and yellow color pattern on their abdomen, which serves as a warning to predators. They have lance-like stingers with small barbs and, unlike bees, can sting multiple times. Yellowjackets build paper nests made from chewed cellulose. Their nests can be found underground, in hollow trees, or in human-made structures.

Behavior

Yellowjackets are social insects with a caste system that includes queens, males, and workers. They are known for their aggressive behavior, especially in late summer and early fall when their populations peak and food becomes scarce. Yellowjackets feed on sugars and carbohydrates, often becoming pests at outdoor events where food or drinks are served.

Life Cycle

The yellowjacket life cycle begins in spring when a fertilized queen emerges from hibernation to establish a new colony. She lays eggs that hatch into larvae, which are fed by the queen. As the colony grows, worker yellowjackets take over the duties of expanding the nest and feeding the larvae, which includes preying on other insects. In late summer, the queen lays eggs that develop into new queens and males. After mating, these new queens find places to overwinter, and the cycle begins again the following spring.

Control and Management

Managing yellowjacket populations near human habitation is important to reduce the risk of stings. Methods include trapping, baiting, and carefully removing or destroying nests. However, because yellowjackets are beneficial predators of pest insects, control measures should be considered carefully to avoid unnecessary harm to the ecosystem.

Health Risks

Yellowjacket stings can be painful and, for individuals with allergies to wasp venom, potentially life-threatening. Anaphylactic reactions require immediate medical attention. It is advisable for individuals with known allergies to carry epinephrine auto-injectors.

Conservation

While yellowjackets are often viewed negatively due to their aggressive nature and potential health risks, they play an important role in controlling pest populations and pollination. Conservation efforts focus on maintaining their habitat and ecological role while managing their numbers in areas of human activity.