Factors affecting use of mirex‐poisoned protein baits for control of European wasp ( Paravespula germanica ) in New Zealand

A bait of canned fish poisoned with 0.5 % or 1 % mirex substantially reduced populations of the European wasp, Paravespula germanica (Fab.), in a part‐cleared, part‐forested resort area in the Marlborough Sounds. In separate baiting regimes, bait was taken for as long as 9 weeks when 0.5% formulation was offered from 5 stations, but when 1 % formulation was offered from 10 and from 15 stations the time was reduced to 5 weeks and 4 weeks respectively. Synthetic and extracted materials tested as baits were unattractive to wasps, but fish baits attractive when fresh could be freeze‐dried without loss of acceptability. Marked wasps were caught up to 1200 m from their nests, and in the control programme 64 ppm mirex was recovered from dry brood comb of a defunct nest 700 m from the nearest bait source. The importance to bait control programmes of data on flight distance and foraging habits, and of the winter survival of colonies with prolonged queen production, is discussed. Some observations on reproductive biology are made in an appendix to the paper.