Colony phenology in the native range of an ecologically damaging yellowjacket
David Rankin, David Rankin , Kevin J. Loope , Erin Wilson Rankin
University of California, Riverside, USA; University of California, Riverside, Riverside, CA, USA ; University of California, Riverside, Riverside, CA, USA ; University of California, Riverside, Riverside, CA, USA
Vespula (yellowjacket wasps) includes some of the world’s most ecologically damaging insects. This may be in part due to plasticity in life history traits shifting from annual, monogyne to a perennial, polygyne colony cycle. Western yellowjacket (Vespula pensylvanica) is native to the western US, where it primarily has an annual life cycle over most of its native range, but in its introduced range of Hawaii 5-20% of V. pensylvanica colonies exhibit a perennial life history. Here we describe colony phenology of annual, overwintering and perennial colonies in the southern part of its native range. Out of 20 colonies that we monitored in southern California, 14 exhibited a typical annual cycle of gradual decline into the winter, while 6 colonies overwintered. We also report interspecific interactions of overwintering colonies with Cassin’s Kingbirds, a known predator of Vespula wasps, and invasive Argentine ants (Linepithema humile).