**Umbrella Wasps** refers to the various species of **Paper Wasps** (*Polistes* spp.) that construct exposed, umbrella-shaped paper nests. They are generally reddish-brown or black/yellow and live in small, annual colonies. The conflict is **defensive stinging and public health risk**: while they are beneficial predators of caterpillars, they are highly aggressive and readily sting when their nest is disturbed, posing a severe risk to allergic individuals.
Taxonomy and Classification
Umbrella Wasps belong to the Family Vespidae (Vespid Wasps). They are social, forming annual colonies started by a single fertilized queen (foundress).
Physical Description
Adults are 15 mm to 25 mm long.
- **Adult (Key ID):** Slender body with a narrow waist; long legs dangle noticeably during flight; color varies by species (many are red, yellow, or black/yellow).
- **Nest (Key ID):** Gray, exposed paper comb (cells visible), attached to a structure by a single central stalk (pedicel). Often found under eaves, decks, or porches.
- **Sting ID:** Painful sting; capable of stinging multiple times.
- **Conflict:** Public Health, Nuisance.
Distribution and Habitat
Found worldwide, especially in urban/suburban environments. Habitat is sheltered outdoor areas where the nest is protected from rain and wind.
Behavior and Conflict
The conflict is their protective behavior near human activity.
- **Predation:** Workers are beneficial, actively hunting insects (especially caterpillars) to feed their larvae.
- **Nest Defense:** They will vigorously defend the nest, especially as the colony grows larger late in the summer.
Management and Prevention
Management is **Targeted Nest Removal**.
- Applying an aerosol wasp spray or insecticidal dust directly to the nest opening, optimally **after dark** when workers are inside.
- Removing newly constructed nests early in the season (when they are small and contain only the queen).
Conservation and Research
Research focuses on their communication systems and their ecological role as natural regulators of herbivorous insects in agricultural and garden settings.