Biological control of Light Brown Apple Moth (Epiphyas potvitanna) in the Adelaide Hills

Abstract

Biological control of Light Brown Apple Moth (Epiphyas potvitanna) in the Adelaide Hills

Summary

The biological control of the Light Brown Apple Moth by larval parasitoid wasps was researched in five vineyards in the Adelaide Hills. Of the five vineyards, four were Chardonnay and one was Sauvignon Blanc. Fortnightly monitoring of 100 shoots per hectare (chosen at random) were monitored from shoot tip to cordon for the presence of LBAM larvae and egg masses. Larvae were then dissected under a microscope to determine if they had been parasitised or not. Dissections allow quick determination of LBAM larvae to see if they have been parasitised or not however, this method is terminal for both the LBAM larva and the parasitoid larva. This results in the parasitoid larvae not being able to be identified.

LBAM pressure was a great deal less in the Adelaide Hills in 2002/2003 compared to 2001/2002. Only one of the five vineyard warranted spraying to control LBAM although three of the five sprayed despite LBAM levels being of no real concern for the season. This unwarranted spraying probably resulted in less LBAM larvae and therefore a smaller sample size. This research found that parasitism levels of LBAM larvae varied from 0% to 100% which shows exactly how much of an impact parasitoid wasps are having on LBAM larvae. As a result of this project, further research could also be done to determine what level of LBAM larval parasitism is required to have an impact on a particular LBAM generation and therefore potential damage.

Another interesting topic which could be researched further is what percentage of LBAM larvae in bunches would be safe to leave untreated depending on the level of LBAM larval parasitism. This research has already been done in other crops such as Brassica’s.