European hornets are the only true hornet found in the state of Pennsylvania. They are also called giant hornets and “gentle giants”. They get their name because of their introduction from Europe in the New York area in the 1800’s.
European Hornet Identification
European hornets are the largest of the social wasps and measure over an inch long. They look like large yellow jackets and you can hear a low hum when they fly by. They are reddish-black to brown in color with yellow stripes on their abdomen with a pale face. Their large size can make people fear them, but they will only bother you if they feel threatened. Unlike any other social wasps, European hornets will be more active and forage at night. They will fly around outdoor light fixtures and bang against the glass of windows that are lit and will do it repeatedly. European hornet colonies can contain 300-500 workers but can number up to 1,000 wasps.
Damage & Stings of European Hornets
These hornets will cause damage when they eat the sap of trees and shrubs and use the bark to build nests. This can cause the trees to die and is the biggest reason that European hornets are considered pests. They have smooth stingers that allow them to sting over and over again. These stings are painful as they carry venom and will be itchy and swell for about 24 hours. These stings carry the same risk as other insect stings as far as allergic reactions go.
European Hornet Nests
European wasps will nest inside wall cavities, attics, chimneys, trees and will also nest in the ground at times. If nests are built in wall voids they can emit a stench. Their nest can sometimes resemble a football as it is a brown-colored mass that protrudes from a structure. European hornets do well flying in the rain but will usually find protection from the elements. For this reason, nests are usually not exposed completely. They are most active in early spring and summer. The earlier the weather warms up, the earlier the queen can establish a nest. This also leads to a more severe problem later in the summer. How aggressive they can become will all depend on their proximity of humans to their nest and any threat to it. They are not typically aggressive but can be if they feel threatened.
European Hornet Nest Prevention
You want to avoid hornet stings at all costs. To make your home less attractive, you can change outdoor bulbs to yellow ones and pick up any fallen fruit that will attract them. If you find openings into your home, they need to be sealed with caulking.