New Zealand Journal of Ecology (1998) 22(2): 205- 208

Spread of the wasp parasitoid Sphecophaga vesparum vesparum following its release in New Zealand

Research Article
N. D. Barlow 1
J. R. Beggs 2
H. Moller 3
  1. Biological Control Group, AgResearch, P.O. Box 60, Lincoln, New Zealand
  2. Landcare Research, Private Bag, Nelson, New Zealand
  3. Department of Zoology, University of Otago, P.O. Box 56, Dunedin, New Zealand

The measurement of parasitism rates of wasp nests;lt Pelorus Bridge, New Zealand, at different distances from the initial release point suggests that the mean displacement of the parasitoid has increased by 1—1.5 km y(-1) from 1988 to 1993. Since average parasitism rates within this radius at any given site show little trend over time, this suggests an approximate 3-fold increase in the total parasitoid population each year, two-thirds of which is devoted to dispersal and one-third to maintaining local populations.