14 May 1999

Software may help to beat blowfly threat

COMPUTER software designed to predict blowfly activity could help producers adopt more efficient methods of fly-strike control.

After 10 years of research into blowfly ecology, University of Bristol zoologist Richard Hall hopes to launch a new software programme, Strikewise, next spring, reports the Sunday Times.

The program works by predicting when blowfly will start laying eggs in sheep fleeces. This means producers can take appropriate action at the right time and cut chemical use, he says.

Producers will be able to subscribe to the service, which will be run by an academic spin-off company, Pestech. It will provide an information sheet every four weeks warning of strike levels and occurrence.

The program requires certain variables such as temperature and rainfall to accurately forecast the chance of blowfly strike. "This will allow producers to alter the time they shear sheep to avoid strike.

"For example, after a wet spring there will be lower blowfly numbers, so producers might be better off shearing their sheep later than usual, when fly-strike risks will be higher.

"This information will allow producers to rationalise insecticide use and take less drastic control measures. We will produce a list of control options, allowing producers to make their own decisions," says Dr Hall.

One example is choosing to use a growth regulator rather than an insecticide if you know when the fly is going to emerge, he adds.

As well as making treatments more timely and cost effective, reducing labour time and relieving some dip disposal concerns, this development could help reduce worries over OP dip use, he says.

Besides Strikewise, the university has also developed traps to help control fly populations. These are based on a synthetic compound which smells like sheep, attracting flies, says Dr Hall.

"It is rather unpleasant smelling, but this attracts the flies into the trap where they are killed by an insecticide."

Traps are being trailed on some farms in the south west this year, and should help stop blowfly populations increasing, says Dr Hall.

lThe first case of fly-strike this season has been reported in East Anglia, warns Novartis. &#42