SOCIAL WASPS: The most common social wasps in Pennsylvania include paper wasps (Polistes species), yellowjackets (Vespula species), bald-faced hornets (Dolichovespula maculata), and European hornets (Vespula crabro). These are all paper wasps that have different common names, they collect wood and transform it into pulp for the construction of their paper nests. Paper wasps, bald-faced hornets, and European hornets build their nests above ground, while yellowjackets typically excavate nests underground.

Social wasps can be aggressive when defending their nest and females can deliver repeated stings when threatened. This is in contrast with honey bees, who sacrifice their life with just one sting.

Wasps are often overlooked as pollinators, but similar to bees and butterflies, many wasp species visit flowers to drink nectar, and some even collect pollen. However, wasps are unlikely to sting unless they are defending their nest or if they are physically threatened.

Please note that the Asian Giant Hornet (also called the murder hornet or sparrow hornet) has not been found in Pennsylvania, and has only been reported in Washington State. For more information on this species, and how to identify it, please refer to the Extension fact sheet Asian Giant Hornets .

Northern paper wasps and European paper wasps make their nests on eaves and overhangs. Northern paper wasps are native to Pennsylvania and their coloration ranges from brown to light red. Paper wasps are not defensive unless their nest is threatened. The queen wasps will establish nests in May and the wasps cease reproduction in late summer.

European paper wasps were introduced from Europe in the 1980s. These invasive wasps are yellow and black and may be mistaken for yellowjackets.