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Tasmania worms, flies and lice update - February 2016

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


Lower Macquarie
Lower Macquarie

The Lower Macquarie is as full as a fish and chip shop on Good Friday. You might assume it has rained (and it has), but the Lower Mac is a tail-water for Poatina power station, which is emptying the Great Lake at a prodigious rate as Tasmania slips towards being the land of the long, cold shower.

Now the rain: 125mm here in Perth and up to 225mm on the east coast and upper Fingal valley. A real lifesaver, although follow-up is needed. More on the rain later.

The worms have been predictably quiet, with just a few blowouts in Worm Egg Counts (WECs) in Merino weaners grazing dry perennial pastures and some cross-bred (XB) lamb mobs on irrigated grass. The Merinos mostly have Nematodirus, and the XB lambs are all strongyle eggs, most likely Trichs (black scour worm).

The message is to keep monitoring and drench at appropriate targets: less than 200 epg for the lambs on irrigation and 100–150 for merinos on dry perennial pastures.

This, in effect, will be a second summer drench. While the rain will make for worm friendly conditions, it’s unlikely that there will be an explosion. Hopefully, the big bake will have killed most of the larvae deposited in the spring and early summer. Nevertheless, monitor adult dry sheep on perennial pastures and give them a second summer drench if needed.

Back to the rain: the big falls occurred in a relatively short 36-hour period. A drive up the Fingal Valley and the northern midlands showed lots of damage with many paddocks washed bare. It shows that instead of using drought lots and sacrifice paddocks, some places have become sacrifice farms. But that little rant needs a different forum.

We can expect a late fly season. It has been hot, humid and relatively windless since the rain: ideal conditions for the blowies. Importantly, the rain was so heavy that some products may have washed. Even dicyclanil, which sticks like Araldite, may have its activity diminished. Other products are not so rain-fast. Watch treated mobs closely and carefully consider whether you need a fly preventive for untreated mobs.