Abundance of common and German wasps (Hymenoptera: Vespidae) in the honeydew beech forests of New Zealand in 1987

Abstract

Abstract German wasps (Vespula germanica) and common wasps (V. vulgaris) were collected in the northern half of the South Island, New Zealand, in summer and autumn 1987, mainly from beech (Nothofagus) forests infested with the honeydew beech scale insect (Ultracoelostoma assimile). Both the numbers of wasps and colony size peaked in March or April, then subsided in winter. Most common wasp colonies died in June and none survived beyond early July. Wasps were most numerous in areas where honeydew was present, and where both common and German wasps occurred together. German wasps were fewer in the presence of common wasps than in their absence, perhaps because of competition. If the patterns observed in 1987 are maintained, the spread of common wasps into areas already occupied by German wasps will probably cause overall wasp numbers to increase in late summer and autumn.