Load-Lifting Capacities of Three Species of Yellowjackets (Vespula) Foraging on Honey-Bee Corpses

Abstract

1. Other than descriptions of the types of foods taken, little is known of the foraging strategies of social wasps. We examined foraging behaviour of three species of yellowjackets, Vespula germanica, V. squamosa, and V. maculifons, on dead honey-bees (Apis mellifera). 2. Large numbers of yellowjackets were captured from their nests and their lift capacities predicted based on flight muscle mass. 3. Yellowjackets foraging on honey-bees were collected and the masses of their loads measured. 4. Vespula germanca had the highest predicted load-lifting capacity, followed by V. squamosa and V. maculifrons. 5. Vespula germanica carried heavier bee segments than V. squamosa, but both species carried bee parts approaching, but not exceeding, the maximum predicted load. Vespula maculifrons would not forage on dead honey-bees. 6. Lift constraints appeared to limit the mass of prey carried by V. germanica and V squamosa, but handling time and energy cost may play a part in determining the degree to which prey mass is optimized