Numerous wasp species inhabit the northeastern US, and many of these species are not actually native to the country. The non-native German yellow jacket species was first found in the US when specimens were collected from Ithaca, New York back in 1891. This species remained rare in the country until the 1960s when specimens and their nests were found in several northeastern states. By the 1980s, the German yellow jacket had colonized the eastern US as well as several western states. Today, the German yellow jacket has replaced the native eastern yellow jacket as the dominant yellow jacket species in the eastern US. German yellow jackets construct carton nests within hidden areas, and they rarely construct exposed nests. Nests are commonly located beneath the ground on residential lawns where colonies often become disturbed by walking humans, pets, and loud machinery, like lawn mowers.

German yellow jacket queen overwinter within well-insulated locations, such as bundles of dead plant matter, outhouses, homes, buildings and beneath tree bark. Once spring arrives, queens emerge and reproduce with a packet of stored sperm collected from males during the previous year. During this time, queens search for suitable nesting sites where a colony is not likely to be distrubed. Common nesting sites can be found below the ground, behind retaining walls in gardens, within indoor wall voids and attic spaces. Founding queens begin nest construction by using their mouthparts to mix saliva and nearby sources of dead wood to create a wet paper-like material that hardens as it dries, similar to papier-mache. This hard nesting material is known as carton, and as a colony grows, workers construct additional carton galleries. Typically, German yellow jacket nests grow to the size of a football by mid to late summer. Workers regularly leave nests in order to forage, and most stings to humans are inflicted by foraging workers. Foraging workers wasps can forage as far as 10,000 feet from their nest, but they generally remain within 1,500 feet from their nest. Queens can travel at a few miles from their nests, but since queens usually remain within their nest, no data on their travel distances have been gathered.

Have you ever sustained one or a few yellow jacket stings? If you have, were the stings inflicted by foraging workers or by an angry colony?