Yellow jackets are large Wasps that are closely related to Hornets. Sometimes the names become confused because the only difference between yellow jackets and hornets is size; yellow jackets are smaller. Yellow jackets and hornets are all members of the insect family Vespidae in the order Hymenoptera.
In Canada there are several species of yellow jacket wasps. Among these are the common (Vespula vulgaris), German (V. germanica) and aerial (Dolichovespula arenaria) wasps. Yellow jackets can be found throughout Canada, except in the far north, although the species V. albida and V. austriaca have ranges that extend to the treeline and even a little beyond.
Members of Vespidae are social insects that nest in populous colonies with a reproductive egg-laying queen, female but sexually sterile workers and males or drones. Nests are built of wood fibres masticated into coarse paper and are attached to trees, shrubs or eaves, or are hidden in wall cavities, hollow trees or under the ground.
As do most wasps, yellow jackets feed voraciously on other insects and so are beneficial by consuming crop and garden pests. However, the nuisance and risk of being stung may outweigh the benefits these insects provide, especially in urban areas.