Evaluation of the Sterile Insect Technique for sheep blowfly control

Summary

Sheep blowfly (SBF) strike is a substantial annual impost on profitable sheep production in Australia. Current management relies on the use of chemicals, surgical breech modification (mulesing) and seasonal wool removal.

This project investigated the feasibility of using the sterile insect technique (SIT) to reduce the risk of flystrike.

Australia has the capacity to upscale mass rearing of sterile males in 1-2 years (using existing knowledge and facilities) for areas of 2000-5000km² (e.g. Kangaroo Island). After upscaling, SBF could be eradicated in 3-4 years for an estimated $5-6m, includes facility establishment that could later be repurposed.

Objectives

The main objectives of this project were to complete:

• a literature review and assessment of the potential for SIT
• a benefit/cost analysis of the impact of the development of SIT
• research plans for a full proposal to develop and trial SIT for blowfly control in Australia.

Key findings

• SIT is used successfully against sheep blowfly in Bangladesh.
• Australia has the capacity for mass rearing of sterile males (using existing knowledge and facilities) for areas of 200,000 – 500,000ha.
• This report finds SIT feasible in consideration of some of the factors that have limited success in the past (e.g. lack of natural boundaries that might help control the migration of blowfly colonies).

Benefits to industry

Flystrike infestations can cost the industry up to $173m annually in stock loss, productivity loss, and control measures. These losses can be potentially mitigated by reducing sheep blowfly numbers through the SIT.

MLA action

• The final report will be considered in the light of an extensive literature review to determine the most appropriate direction for possible future research into flystrike.

• MLA has expressed support for a jurisdiction wishing to proceed with the establishment of a sterile male production facility.

Future research

• The researchers propose launching the development of SIT for area-wide blowfly management as technically and economically feasible.
• SIT for SBF can be applied in ‘high density’ island situations in cool climate areas of up to 5000km2 as soon as the SBF rearing has been scaled up.
• Eradication of sheep blowfly on Kangaroo Island would be achievable in 4-5 years.