If you are concerned your population of flies is showing resistance to the chemicals you use, you can have a resistance test carried out.
NSW DPI are now conducting laboratory tests, which are open to producers from all states, to determine the presence of resistance to various chemicals.
You will need to supply a large sample of live, healthy Lucilia cuprina maggots to the laboratory.
Collection instructions
1. Contact the laboratory to get a collection kit, with detailed instructions sent out to you.
Narelle Sales, NSW DPI
Elizabeth Macarthur Agricultural Institute
Direct T: 02 4640 6446 Switchboard T: 02 4640 6333
E: narelle.sales@dpi.nsw.gov.au
2. When a flystruck sheep is found, take it to the shearing shed and ideally machine shear, rather than hand shear the strike wound to recover more maggots—at least 60 healthy maggots are required.
3. Keep the container of maggots out of the sun in a cool place, but NOT the refrigerator or freezer.
4. Complete and include the required submission form.
5. Post the sample to the laboratory the next day if possible, use the Reply Paid Post Pack supplied, and include the completed submission form.
** If the proper collection kit is not immediately on hand, you can use a fully sealable container (e.g. two plastic vitamin containers) with about 6 needle holes in each lid (no bigger or the maggots escape) and a small handful of completely dry dirt or sand that does not contain any small pebbles.
The insecticides that can be tested, with examples of the products containing them, are as follows:
Each of the dot points above represents a different insecticide group.
Pricing
Further information
Narelle Sales, NSW DPI
Elizabeth Macarthur Agricultural Institute
Direct T: 02 4640 6446 Switchboard T: 02 4640 6333
E: narelle.sales@dpi.nsw.gov.au
Resistance of flies to preventative and treatment chemicals can be managed to slow the development, especially if caught early—before obvious signs of resistance.