Research at Bristol has shown that simple sticky flytraps make an effective contribution to blowfly management on individual farms. For example, on 12 commercial sheep farms in south west England in 2003, the highest strike incidence was seen in two control flocks (no traps or chemical preventative) where 10.9% and 5.8% of the ewes and 10.1% and 9.2% of the lambs were struck. Strike incidence in the flocks that used the traps only, or in flocks that used traps plus a chemical preventative, was on average 5 times lower but the percentages struck on the sites in the trapping only and trapping plus insecticide groups were not significantly different from each other. (Broughan and Wall, 2006).
Results show that traps can be a practicable option to control blowfly populations in small flocks. With larger flocks they should be used as a monitoring and warning device to improve the timing and efficiency of chemical intervention.
As daily temperatures increase through the Spring, the blowfly population will also increase. Traps should be put out in fields in early April when the temperature starts to rise.
- Traps should be sited in fields or pasture where sheep are grazing. If sheep are moved to fresh pasture, traps should be moved with the flock.
- Traps should be positioned around the field and ideally in areas where blowflies tend to gather such as near water troughs, where sheep tend to congregate and in areas where there is a maximum amount of sunlight.
- It is important to place traps in full sunlight in order to maximise the number of flies attracted to the trap. Avoid shaded areas.
- Traps should be positioned about 1m above the ground but no more than 1.5m.
- Traps need to be inspected on a weekly basis and any sticky strips, which are full of flies replaced. In addition the bait bottle should be topped up with water.
Warning: Keep out of reach of children and pets
