invasivespecies.ucsd.eduImages
Ongoing studies investigating the ecological effects of V. pensylvanica.
Currently, we are using genetic analysis
of prey items (as shown above) to characterize the yellowjacket diet in its
introduced range and determine whether endemic arthropods are particularly
vulnerable to V. pensylvanica predation.
Photo: Erin Wilson
Through the use of trap-nests (as shown above), we are characterizing the diet of predatory wasps native to
Hawaii. With these data, we will quantify the degree of diet overlap which
will provide insight into the competitive interactions between native and
introduced wasps.
Photo: Erin Wilson
V. pensylvanica on Styphelia tameiameiae
Photo: Erin Wilson
Vespula pensylvanica
Western yellowjacket
Native range
Western United States, from Washington to Baja California.
Introduced range
Hawaii, first introduced in the late 1970s
Threat to native communities
The Hawaiian islands have no native social insects. Therefore, endemic Hawaiian species have evolved in the absence of predatory social insects and may be particularly sensitive to their introduction. Vespula germanica and V. vulgaris have invaded New Zealand and Australia where these yellowjackets have decimated native populations of arthropods and outcompeted endemic birds.
Diet
Adults are nectivorous and derive their carbohydrates from nectar and fruits. However, adult foragers are adept predators and hunt live arthropod prey or scavenge on carrion, which is carried back to the nest and fed to the carnivorous larvae.
Nesting habits
Subterranean, these wasps do not store any food in the nest.
Nest entrance to annual nest (Sliding Sands, HALE)
Photo: Amy Lin
Nest entrance to perennial nest (Kipuka Puaulu, HAVO)
Photo: Megan Eckles