SCOPS launches Blowfly Emergence Forecast to help sheep farmers stay ahead of flystrike risk

The Sustainable Control of Parasites in Sheep (SCOPS) is pleased to announce that from today (Monday 13th April) it will be hosting a Blowfly Emergence Forecast on its website. This decision support tool will help sheep farmers take a proactive approach to flystrike prevention, providing an early warning, prompting close inspection and preventative strategies.

The blowfly forecast is separate from the SCOPS Nematodirus forecast but uses the same high quality weather data from over 140 weather stations around the UK to accurately inform farmers.

“Prevention is always better than cure when it comes to flystrike. Once strike occurs, the consequences for sheep welfare and productivity can be severe. Having an accurate indication of when blowflies are first emerging in spring allows farmers to put preventative measures in place in good time,” says Kevin Harrison, Chair of SCOPS.

Why an emergence forecast matters

Flies overwinter as pupae in the soil and emerge in spring. Recent years have seen increasingly variable weather patterns, leading to blowflies emerging earlier – and sometimes later. This variability means farmers can be caught out if they rely solely on fixed calendar-based routines.

The SCOPS blowfly forecast focuses specifically on predicted blowfly emergence, not on flystrike cases. It presents risk using a simple colour-coded system:

• Grey – Fly emergence unlikely
• Yellow – Fly emergence possible soon
• Orange – Fly emergence likely soon
• Red – Flies emerging

Once an area reaches red, it will remain red for the rest of the blowfly season, because once flies are present, they remain capable of causing strike if conditions on individual farms allow.

SCOPS stresses that emergence risk is not the same as cases of flystrike.

Whether strike occurs on a particular farm depends on several local factors, including:

• Fly population levels
• Weather conditions
• Fleece length and cleanliness
• Grazing environment and field shelter

The forecast should be used as an early warning tool, prompting farmers to check sheep more closely and consider appropriate preventative strategies.

Farmers, SQPs and vets urged to report flystrike cases

To further validate and refine the forecast, SCOPS is encouraging farmers, SQPs and vets to report confirmed cases of flystrike using the existing Elanco flystrike reporting system, which records cases by postcode. The reporting tool can be accessed via a link on the SCOPS website and provides valuable national‑level intelligence on seasonal trends. The reporting tracker is hosted on Elanco’s website, and the data submitted will be used solely to populate the tracker map and to validate the blowfly emergence model.

The blowfly emergence forecast has been developed by the Queen’s University Belfast research team, drawing on additional expertise from Dr Richard Wall and Dr Hannah Vineer, whose work has been instrumental in improving understanding of blowfly biology and flystrike risk in the UK. The development and ongoing support of the forecast is supported by Elanco.

SCOPS encourages all sheep farmers to make use of the forecast alongside regular flock inspection, effective management and targeted preventative treatments to protect animal welfare throughout the blowfly season.
For more information, visit https://www.scops.org.uk/forecasts/blowfly-forecast/