Yellowjacket or yellow-jacket is the common name in North America for predatory wasps of the genera Vespula and Dolichovespula. Members of these genera are known simply as “wasps” in other English-speaking countries.
Most of these are black-and-yellow, some are black-and-white (such as the bald-faced hornet, Dolichovespula maculata), while others may have the abdomen background color red instead of black.
Wasps belong to insect order Hymenoptera which is also shared by bees. Quite different from bees, which only sting once, wasps are stinging insects that are able to withdraw their stings for use again and again.
A wasp has wasp-waist caused by a deep constriction between the thorax and abdomen. They have two pairs of membranous wings and have yellow and black markings on their bodies.
They develop with complete metamorphosis: egg, larva, pupa and adult. The adult wasps are of three forms: male, female and worker. The males and females are reproductive with the females (or queens) founding the nests and laying eggs. The workers are sterile females. Each female and worker wasp is armed with a sting used for defence against predators. The male is unarmed.
A new nest is started by a single female (queen) in the spring. After several generations and under favourable conditions, new males and females are produced in the summer or autumn. The fertilized females then hibernate over the winter and become active in the spring.