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Queensland worms, flies and lice update - June 2020

QLD WormBoss Worm Control Programs

QLD WormBoss Drench Decision Guides





Brisbane: Maxine Murphy, Veterinary Parasitologist (

Winter has arrived with an icy blast, and more is on the way.

It is going to be too cold for barber’s pole to progress through its life-cycle on pastures, but every day eggs will still be dropped from infected sheep. Most of these eggs will die, but if temperatures warm slightly and some rain falls, they have the potential to hatch into infective larvae.

Black scour worms are more resilient to these colder conditions, but their numbers build slowly and not to the levels usually seen in southern states. Request a larval culture with the next WormTest.

Worm control efforts at this time of the year concern paddock preparation for the pre-lambing ewes. Late-pregnant ewes are particularly at risk as worm immunity falls in late gestation and early lactation. Decisions, such as which paddocks will have the best nutrition and the least amount of larval contamination, as well as about worm testing and drenching, have to be made.

Drench Decision Guides

The first two questions asked by the drench decision guide for slopes and plains are:

If there are signs of worms, then sheep need to be worm tested if not already done so, and treated. Similarly for the ewes about to lamb.

If you are on the tablelands, the first question is about lambing, and the reply says to treat lambing ewes with an effective short-acting drench and then to WormTest one week before lamb marking because … In a well-prepared low worm-risk paddock, most ewes should not need treatment at lamb marking; this test is the indicator of how well the paddock has been prepared.

In the much colder tablelands areas of southern Queensland, paddock preparation may take up to six months, but there is an upside. If you are in a ‘cold zone’ you can happily graze wormy stock on the paddocks ear-marked for lambing for a few weeks when daily maximums are consistently below 18°C.

For June 2020 state outlooks, please follow the links below:
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