The analysis of Painted Apple Moth Trap Catches in Auckland
by
David Baird
AgResearch

Painted apple moth (PAM) was found in Glendene, Auckland in May 1999 and was later discovered in Avondale, Glen Eden, Kelston, Titirangi and Mt Wellington. MAF recognised how serious the impacts of this pest could be – more so than white-spotted tussock moth. Eradication was a priority, supported by the early establishment of a Technical Advisory Group. PAM is native to Australia where it is a sporadic pest. In New Zealand, the moth threatens forestry and horticulture, as well as the natural environment. The caterpillars are indiscriminate feeders. While they prefer wattles and acacia trees, they have also been found feeding on three native species: kowhai, karaka, and mountain ribbonwood.

Live moth trapping started in December 2000 and now over 600 traps cover west Auckland through to Mt Wellington. The catches in these traps have been analysed to access the population growth and spread of PAM. The model used was a generalized linear model based on the location of caterpillar finds, and used splines for the temporal and spatial components. The results from the model have been successfully used to predict locations where new caterpillar finds are likely, as indicated by higher than expected moth catches.

Date received: April 23, 2002