The outer walls of the nest and the individual cells for the larvae are made of a mixture of wood and saliva. This creates a layer of protection. Within it, yellowjackets are able to regulate the temperature of their environment by fanning their wings. Nests are usually subterranean or near to the ground and contain 1000-4000 workers.
This species is abundant and successful thoughout its range.
US Federal List: no special status
CITES: no special status
State of Michigan List: no special status
Chewing and sucking of fruits meant for human use causes crop loses. They take parts of domestic plants for the construction of the nest. Can cause serious injury to humans with sting. Can transmit a disease called Fire Blight to potato crops.
Yellowjackets are predators of some insects which are harmful to domesticated plants. They have been used in the biological control of other pest species. They also aid in the production of some fruits by pollinating the flowers. Behavior and sociobiology of some "higher animals" have been studied using yellowjackets as a guide.
Adults commonly feed on nectar and the jucies of ripe fruits. Workers prey upon smaller insects, such as caterpillars, and feed the macerated insects to the larvae of the colony. Adult mouthparts are designed for chewing, catching, and sucking.
Throughout North America as far north as the Arctic Circle
Biogeographic Regions: nearctic (Native )
Other Physical Features: ectothermic ; bilateral symmetry
Reproduction is sexual. A fertile female becomes impregnated at the end of a season by a haploid male. She then hibernates though the winter and founds a new colony the following spring. The larvae are maggot-like while the adults resemble the queen in many respects. The queen controls the sex of her offspring, and she produces haploid males only at the end of the season, to insure the founding of new colonies.
