UPFRONT fall armyworm
Macquarie University researchers, led by Dr Vivian Mendez, have achieved a significant milestone under Hort Innovation project AS21000, “Effective Fall armyworm (FAW) pheromone blends for improved monitoring and population estimation in Australia”.
Written by Dr Rehan Silva Edited by Dr Vivian Mendez, Macquarie University
First phase of the project
The first phase of the project was to determine the effectiveness of four commercially available lures for monitoring FAW: FAW lure (ISCA), Pherolure (Insect Science), Frugilure (Chemtica) and Pherocon (Trécé). Working closely with regional communities and major growers across Australia, the project team have now installed FAW pheromone lure traps at 30 sites across 16 locations in 4 states (Figure1) for a total of 480 traps.
The trials will be carried out for a year to determine seasonality and population abundance of FAW in the 4 states, as well as the effectiveness of each lure in attracting FAW with minimal non-target by-catch in each region across the year.
Preliminary findings
Data already indicate substantial differences between the lures both in efficacy at attracting FAW and in the amount of by-catch. Further, the tested lures perform differently in different regions, varying in the attraction of FAW and False Fall armyworm males. As illustration, Figure 2 shows the number of moths trapped at field sites in Toowoomba, Darwin, Tolga and Geraldton.
A total of 480 FAW pheromone lure traps have been installed at 30 sites across 16 locations in 4 states.
The fall armyworm (Spodoptera frugiperda) is a plant pest that can damage a wide variety of crops.
FIGURE 1: Field sites for trials to evaluate the effectiveness of four commercial pheromone lures for FAW in Australia
The team is now increasing data on seasonal patterns of FAW abundance and whether the differences between the lures across regions are consistent throughout the year.
Based on chemical analysis of the commercial lures and female sex pheromones collected from the field, modifying the number of compounds and their proportions in the lure is expected to increase the performance of the lure both by increasing the numbers of FAW attracted, and decreasing bycatch.
The findings guide decisions on how the lures can be modified for optimisation in each region and will increase knowledge on FAW abundance during and out of season.
Training and data collection
Prior to setting up traps, inductions were conducted over two months to provide detailed instructions for 17 technicians responsible for trap installation, sample collection, trap maintenance and diagnostics in each region. Samples are collected weekly from the traps and sent to diagnosticians in each state. Technicians were also given guidance on using the KoboCollect app, developed by Cervantes Agritech, which enables efficient data collection using an apple or android device.
Next phase of the project
The project team has analysed the pheromone components of the lures and the proportions of each component. In the project’s next phase, the team will refine lures based on the proportion of compounds found in pheromones produced and emitted by FAW in each region. The FAW pheromone blends in each region need to be analysed to guide modification of the lures.
The research team has started collecting and analysing pheromone blends in the laboratory using adults that originated from eggs, larvae and pupae collected from different regions, using three different methods. Substantial variation in pheromone blend has been found in moths from different locations, highlighting the need to understand regional variants of pest insects rather than assuming that data collected from domesticated insects or insects from any one location can be generalised to other regions across Australia.