There are several species of this group of wasps found in the North Central United States. Whitejackets and bald-faced hornets are close relatives that are black and white. Both are aggressive and nasty stingers. Depending on the species, the yellowjacket builds its nest underground or in old logs, or builds a large paper nest in trees or houses. The workers scavenge food such as caterpillars or other insects, pieces of flesh from dead animals, or ripe or injured fruit.
Food is taken back to the nest to feed the larvae.
Yellowjackets are attracted to ripe and injured fruit to feed on fluids and sugars, especially in late summer and during dry weather. Populations of yellowjackets peak in late summer. Yellowjackets can be discouraged by sanitation, which is regular and thorough picking of all berries as soon as they begin to ripen, and frequent removal of overripe fruit and fruit debris. Do not allow pickers to bring sweet drinks, lunches, or other attractants into the planting. Where yellowjackets are attracted to brambles despite good harvest practices, traps offer the only practical method for reducing problems.