CHANGES IN THE DISTRIBUTION AND PROPORTIONS OF VESPULA-VULGARIS (L) AND VESPULA-GERMANICA (FAB) (HYMENOPTERA, VESPIDAE) BETWEEN 1987 AND 1990 IN NEW-ZEALAND

We collected more than 90 000 vespine wasps sent in by members of the public from throughout New Zealand between January 1987 and July 1991. Both the German wasp (established before 1950s) and the common wasp ( established before 1980s) were widespread throughout most of the count ry in 1990. The common wasp had increased its distribution since 1987, mostly in the lower North Island and lower South Island, but was stil l absent from most of Northland, East Cape, and some regions of the ce ntral North Island and southern South Island. The common wasp had almo st totally displaced the German wasp in honeydew beech forests by 1990 and accounted for a higher proportion of most samples from rural habi tats. It had not completely displaced the German wasp in urban and oth er native forest habitats. It accounted for >50% of the vespulid popul ation in the lower North Island and upper South Island. Its abundance had increased relative to German wasps where it was well established i n 1987, as well as in locations where it was still spreading, and in s amples from above 100 m a.s.l. except in southern areas where it was s till colonising at lower altitudes. The different spatial and temporal patterns of relative abundance of these two wasps suggests that diffe rent ecological factors are controlling their distributions in differe nt habitats, altitudinal zones, and geographical regions.