Free tests: Are your sheep blowflies resistant to chemicals?

by | 7 Feb 2019 | In the News, News

Tests that would cost over $3,500 are currently being offered free this flystrike season (2018/2019) by NSW DPI and jointly funded by Australian Wool Innovation.

The tests assess the current level of pesticide resistance in fly populations.

The test is only for the Lucilia cuprina sheep blowfly (more information on identification).

Samples are being accepted from all over Australia.

Collecting and sending maggots for resistance testing

Collecting maggots

  1. If you find a struck sheep, collect the maggots.
  2. Get a collection container now and put it in your ute or bike for when you need it: a plastic container with a sealable lid with very small air holes—maggots need air, but can also escape through larger holes (something like a vitamin jar is ideal).
  3. Before applying more flystrike chemical to the sheep collect at least 30 healthy Lucilia cuprina maggots. These are the smooth, cream maggots—never add brown, hairy or spiky maggots as they eat the others.
  4. Keep them cool after collection.
  5. Maggots will live for 7–10 days this way, but remember they will need a few days in the post, so send them promptly.

Sending maggots

There are 3 ways you can despatch them to the laboratory (depending on your location):

  1. Pack and post them yourself (free post)
  2. In NSW, deliver to your local LLS office (call them in advance)
  3. In advance, get a Collection Kit from your LLS (NSW) or the laboratory (call or email Narelle Sales narelle.sales@dpi.nsw.gov.au, (02) 4640 6446) and post them yourself (freepost)

Method 1. Pack and post them yourself (free post)

  1. Ensure maggots are collected and posted as soon as possible after collection in case they are delayed in the post over a weekend.
  2. Find a small fully sealable plastic container, for example, a plastic film container, a vitamin or pill bottle, a plastic spice bottle or a sheep poo sample container (a matchbox is NOT suitable as maggots can easily escape).
  3. Clean the container thoroughly so previous contents don’t affect the maggots.
  4. Pierce some very small holes in the lid—smaller than the maggots, as they are very good at escaping!
  5. Add 30 healthy-looking maggots.
  6. Fill container with DRY dirt or sand (maggots burrow into the ground normally).
  7. Attach lid tightly and put in the shade (not a hot vehicle) till ready to send.
  8. Prepare an information sheet (no testing done without this information)
    • Your name, address, phone and email
    • Date of collecting the maggots
    • Location of the strike on the sheep, e.g. breech
    • The most recent treatments (and approximate date) for fly prevention and lice applied in the last year to the struck sheep
    • Are you concerned any particular chemical treatments for flystrike are not working on your property?
  9. Pack in a padded post-bag and send to:

Reply Paid 65110,
Attention Narelle Sales
NSW DPI
BC Narellan NSW 2567

Method 2. Deliver to LLS office (if you are in NSW)

  1. Call the LLS to check they have kits on hand (if not pack and post yourself).
  2. Deliver it as soon as possible so they can pack and post to minimise delays.
  3. Prepare an information sheet (no testing done without this information)
    • Your name, address, phone and email
    • Date of collecting the maggots
    • Location of the strike on the sheep, e.g. breech
    • The most recent treatments (and approximate date) for fly prevention and lice applied in the last year to the struck sheep
    • Are you concerned any particular chemical treatments for flystrike are not working on your property?

Method 3. In advance, get a Collection Kit from your LLS or the laboratory and post them yourself (freepost)

  1. Do this if you think you will have an odd struck sheep in next few months and will use the kit.
  2. Call or email Narelle Sales narelle.sales@dpi.nsw.gov.au, (02) 4640 6446 to have a kit sent to you.
  3. Or contact your LLS office to see if they have them on hand.
  4. Follow kit directions (similar to packing and sending it yourself, Method 1 above)

What is being tested and why?

The following chemicals, which represent all of the major chemical groups, for blowflies are being tested: Spinosad, Imidacloprid, Ivermectin, Cyromazine, Dicyclanil, Diazinon and Diflubenzuron.

This project aims to determine the resistance profiles of blowflies and lice across all wool producing states. It is also gathering baseline data on newer chemicals for future reference.

The results for your property will be emailed or phoned through to you.

For flies, the process takes approximately 6–9 weeks because the maggots you send need to be grown into flies and they are then bred for two generations before testing them.

Further information

Call or email Narelle Sales at NSW DPI narelle.sales@dpi.nsw.gov.au, (02) 4640 6446.