Flystrike Management is Not a ‘One Size Fits All’ Approach

Flystrike is again causing a considerable degree of discomfort for sheep and producers across many areas of Australia. The weather forecast for another La Nina is a strong prompt that fly prevention and control this season will again require vigilance, close monitoring, plenty of forward planning, and likely some adaptive management along the way.

This article outlines the conditions required for flystrike to occur, along with a summary of how to give your business the best chance at managing flystrike in the current and forecast conditions.

The three essential conditions required for flystrike are:

1. Presence of susceptible sheep
2. Favourable weather conditions
3. Presence of flies

Without all three, flystrike cannot occur.

Gaining an improved understanding on the Australian sheep blowfly lifecycle and its requirements helps further understand when our livestock are most at risk, and what additional conditions give rise to existing populations and the proliferation of flies locally.

In any integrated pest management (IPM) program, the aim is to find weak spots in the environment, pest life cycle and opportunities to fortify the sheep flock (decrease susceptibility).

A tactical (this season) and strategic (longer term) approach is essential to help with the current problem and help decrease overall impacts of this important and costly parasite.

As with any sheep business, it should come as no surprise that flystrike management is not a ‘one size fits all’ approach – and what will work for one situation may not be the most appropriate course of action for another. Similarly, longer term management options such as breeding are very much an individual based course of action.

Tactically (this season), consideration should be given to controlling what can be controlled in the operation – and this may be internal parasite management, paddock choice and selection to minimise exposure of more susceptible animals to flies, managing strikes, and of course careful selection of preventative chemicals.

Chemical resistance is an important consideration, with many producers reporting decreased protective periods from chemicals. In seasons like this and last season, which are characterised by high flystrike pressure, vigilance is important, along with careful choice of chemicals. Follow up monitoring of treated animals is essential to avoid adverse impacts of fly waves from break down of chemicals due to weather or chemical resistance. Just like managing drench resistance, herbicide resistance, flystrike chemical resistance needs an integrated approach.

In a more strategic context, there are ways of decr