SURVEY OF THE SUMMER/AUTUMN BRASSICA REFUGES FOR DIAMOND BACK MOTH IN THE WESTERN REGION TO PREDICT EARLY SEASON RISK OF INFESTATION
To assess the role of Brassica green bridge on DBM presence and impact on winter/spring population.
Project lead organisation
DPIRD, other grower groups
Diamondback moth has unpredictable population dynamics with its timing and distribution difficult to determine. DBM has the ability to reproduce very fast (i.e. life cycle of about 2 weeks in warm spring temperatures), hence demonstrating explosive outbreak potential as has been seen in WA in some years. In order to improve timely and effective decision support for growers to manage DBM in canola crops, surveillance is being conducted throughout the five WA port zones to determine the Brassica hosts which may be present during summer and autumn and assess whether these hosts are providing a DBM reservoir bridging between growing seasons.
As part of a GRDC-funded project, staff from DPIRD, The Liebe Group, Mingenew Irwin Group and West Midlands Group found and identified DBM larvae in the March green bridge plants, including wild Brassicas (e.g. wild radish) and volunteer canola. Pheromone moth traps were then set up at sites where we found Brassica plants and moths and caterpillars monitored until late October to get a better idea of their spatial distribution.
This project is continuing with the same activities for the 2021 season.
Results and Reports