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Insecticide Resistance

Do you know what insecticides are effective against the blowflies and/or lice on your sheep?


Take advantage of FREE insecticide resistance testing available now to determine the most cost effective ecto-parasite treatments for your property.

This jointly funded AWI and NSW DPI project aims to determine the insecticide resistance profiles of blowflies and lice across all wool producing states. 


 It is also gathering baseline data on newer chemicals for future reference. By participating in the research and providing maggot and/or lice samples, you'll receive feedback on which chemical groups are most effective for your flock.

Recent rains mean flystrike may become a problem. Contact Narelle Sales at DPI NSW who will send you a maggot collection kit to have on hand. Simply place 20 or more maggots into the containers provided, fill in the strike record sheet and put the reply paid Postpak in the mail.

If sheep are already struck simply collect some maggots, place them in a plastic pill or vitamin container with some dry sand or dirt. Prick some small holes in the lid ensuring the maggots can’t escape. Please include your name, address, phone or email address and information about most recent treatments the sheep have received. Please also indicate if you have an interest in knowing about one chemical in particular. Place all of this in a Postpak and mail to:

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

The lab can also determine the insecticide resistance profile of sheep biting lice if your flock is lousy. If sheep are heavily infested i.e. 20 or more lice per parting, send the lab a fleece. Please contact the lab first so we can arrange an overnight courier if logistically possible. (This may not be possible for areas deemed too remote by couriers or if it is price prohibitive). Once shorn the fleece should be loosely wrapped in an old 100% cotton sheet, table cloth or similar. Please do not seal the fleece in anything plastic as the lice will die. Once wrapped the fleece can be sealed in a cardboard box and addressed to:

Attention Narelle Sales
Woodbridge Road,
NSW 2568

The results for your property will be e-mailed or phoned through to you. This process takes approximately 6-9 weeks for blowflies as we have to breed the flies through 2 generations to test. Results are available for lice within 1 week of delivery.

Your confidentiality will be maintained, and results for the project only attributed to a region or state. At the conclusion of the project you will also receive information at a state level and, if enough submissions are received, at a regional level.

For further details, to request a maggot collection kit or to determine if it is possible to transport a fleece for lice testing, please contact Narelle Sales via email at or phone (02) 46406446. Alternatively, you can email Monica Suann at


Sheep displaying rubbing and chewing because of a biting louse (Bovicola ovis) infestation which, given the right conditions, can also result in flystrike.
Sheep displaying rubbing and chewing because of a biting louse (Bovicola ovis) infestation which, given the right conditions, can also result in flystrike. (Copyright NSW DPI)