< Back to Outlooks Listing

Tasmania worms, flies and lice update - March 2018

Tasmania WormBoss Worm Control Programs

Tasmania WormBoss Drench Decision Guides





Perth: Paul Nilon, Nilon Farm Health (pandonilon@bigpond.com)

It’s remained mostly dry. Some promising rain starts have been blown away by the unseasonal winds. Have you ever seen a crow look over its shoulder while flying? I have: over the weekend one that launched into a 60 kn breeze looked backwards for where he was going to land. So far, it’s only rained the beginning of a good ryegrass staggers season.

As with last month the weaned lambs are vulnerable, and adult dry sheep are OK. There have been many Worm Egg Counts (WECs) in lambs on drier pastures with nothing but Nematodirus (nems) present. I was taught way back, and long before Leonard Teal left Homicide, that nems are of little consequence. Well, the Tasmanian version of them must gobble up all the Human Growth Promotants that we are not allowed to give our cattle [destined for export markets] because even modest counts of nem reflect severe parasitism. So, any count greater than 150 eggs per gram should be treated suspiciously. Their egg output is generally low and capricious: even modest counts may reflect a large burden of worms.

Editor’s note: The immature Nematodirus are responsible for the severity of the infection and are not detected on a worm egg count.

There’s been a spate of enquiries about lice control options. As always, first port of call is the LiceBoss website and its suite of tools. An interesting case was where lice were found right at the end of a 3-week shearing, and outside the timeframe for eradication with backliners. We are lucky to have an immersion dipper available operated by Ross Creek Contracting. There is a choice of chemicals for use in the dipper, but thiaproclid (Piranha®) is preferred.

When all is said and done, eradication “failure” is most often a biosecurity problem rather than a chemical failure. The three big issues are multiple shearings, incomplete musters, and new introductions.

On our large Midlands properties with poorly fenced bush runs all three factors may play a role. It’s to be hoped that increased wool values will refocus our lice efforts.