**European Wasps** (*Vespula germanica*) are a highly invasive species of yellowjacket, notorious for their aggressive foraging, persistent presence in urban areas, and extremely painful sting. While native to Europe, they have become a major pest in several regions globally, particularly New Zealand, Australia, and South America. They are opportunistic predators and scavengers, frequently competing with native insect species and disrupting picnics, barbecues, and outdoor dining due to their attraction to meat and sugary drinks.
Taxonomy and Classification
European Wasps belong to the genus *Vespula* (yellowjackets) in the family Vespidae. They are **eusocial insects** with annual colonies in their native range, but in mild climates (like New Zealand and parts of Australia), their colonies can become **perennial**, surviving for multiple years and reaching massive sizes (up to 100,000 workers). They undergo complete metamorphosis.
Physical Description
European Wasps are slightly larger and stouter than the common Eastern Yellowjacket, measuring $1/2$ to $3/4$ inch long. They are easily recognized by their striking black and yellow coloration. They are distinguished from other yellowjackets by the **anchor-shaped or dagger-shaped black mark** on the face (clypeus) and the **solid black dots** on the abdominal segments, which do not merge with the black rings.
Their nests are complex, multi-tiered paper structures built from wood fibers mixed with saliva. Nests are almost always built in concealed voids, usually subterranean (old rodent burrows), or in wall voids, tree cavities, and under eaves.
Distribution and Habitat
Native to the Palearctic realm, European Wasps are now major urban and agricultural pests in many regions outside of their native range. Their habitat is highly adaptable, thriving in both rural forests and dense urban environments. They prefer to nest in dark, protected cavities, frequently utilizing structural voids in homes, making their eradication challenging when they establish indoors.
Behavior and Life Cycle
The colony cycle is similar to other yellowjackets: a single queen establishes the nest in spring. Workers emerge and rapidly expand the nest, foraging for insects (protein for larvae) and sugars (for adults). In the late season (fall), the colony produces new queens and males, which mate, and the old queen and workers die off (in annual systems).
European Wasps are extremely aggressive, particularly in the late summer and fall when workers have no larvae to feed and switch entirely to scavenging sugars. They are also highly sensitive to disturbance near the nest, often attacking in swarms if the nest entrance is threatened. Their stinger is smooth, allowing them to **sting repeatedly**.
Feeding and Conflict
The conflict arises from their large numbers, aggressive defense, and scavenging habits:
- **Nuisance and Health Hazard:** They aggressively invade human food and drink, especially meat and sugar. Their painful, multi-stinging ability is a significant health risk, particularly to those allergic to venom.
- **Ecological Impact:** In invasive areas, they prey heavily on native insects, spiders, and honey bee colonies, dramatically reducing local biodiversity and agricultural yields.
- **Fruit Damage:** They bore into and destroy soft, ripe fruits in orchards and vineyards in the late season.
Management and Prevention
Control of large colonies requires professional intervention.
- **Baiting Programs:** In high-infestation areas, large-scale control programs involve placing liquid baits laced with a slow-acting insecticide. Workers carry the poison back to the nest, eliminating the entire colony.
- **Nest Elimination:** Nests must be treated by applying a long-lasting, non-repellent insecticidal dust directly into the entrance hole after dark. Never block the entrance before treating, as this can force the wasps to chew a new exit indoors.
- **Sanitation/Exclusion:** Keep all trash bins covered and secure, and avoid leaving pet food or sugary drinks outdoors, especially in the fall. Seal all exterior wall voids to prevent nesting.
Conservation and Research
European Wasps are managed as severe invasive pests. Research focuses on developing highly species-specific baits and investigating biological controls (such as parasitic flies or pathogenic fungi) to regulate their population size in areas where they have become perennial and highly damaging.