Plasticity of annual cycle in Vespula pensylvanica shown by a third year polygynous nest and overwintering of queens inside nests

Summary:

Excavations of 4 nests of the western yellowjacket, Vespula pensylvanica (Saussure) (Hymenoptera: Vespidae) in southern California revealed situations that deviated from the typical annual, single-queen life history of yellowjacket colonies. Three nests that were collected well after colony decline (in December through February) consisted of more queens than workers. An additional nest excavated in April (a time when nests are typically being initiated by single foundress queens) revealed a large polygynous nest that was rearing workers, males, and queens, was very active, and was entering its 3rd year. These life history traits show a plasticity of behavior expressed in the warmer regions of the range of V. pensylvanica and may be more common than previously recorded.