IMPACT researchers are putting the bite on midges

A team of scientists in Wales is working flat out to find an answer to the deadly threat of Schmallenburg disease – the virus that causes miscarriages and birth defects in sheep.

So far there have been no cases in Wales of the new disease, thought to have been carried by midges (Culicoides) to the UK from mainland Europe.

And Integrated Management of forest Pests Addressing Climate Trends (IMPACT) project researchers, based in Aberystwyth and Swansea, believe that their latest work on midge control can help reduce numbers of the tiny biting insects, and the chance of their spreading diseases.

They are investigating new natural ways of controlling the tiny pests – which were the cause of blue tongue disease in a small number of areas in England.

The IMPACT project is co-funded by the European Regional Development Fund (ERDF) through the Ireland Wales Programme (INTERREG IVA), COFORD and Forestry Commission Wales.

IMPACT project partner Swansea University has just published its latest findings on work which looks at using a fungus – Metarhizium anisopliae – to control biting midges, populations of which could increase with climate change.

Vaccines for sheep and cattle are already being considered as an answer to the new disease, but could take years to develop.

“New ways of controlling the midge population, which is believed to carry the virus between animals, could significantly reduce the risk,” said Professor Tariq Butt, whose work at Swansea is an important part of the IMPACT project. 

“Current control measures rely on synthetic pesticides, which pose a risk to humans and the environment, whereas natural alternatives do not. With climate change projecting warmer, wetter weather leading to larger midge populations, these could prove a very useful alternative in reducing their numbers.”

The research team already knew that the entomopathogenic - insect-killing - fungus could successfully kill larvae of the midge Culicoides nubeculosus and, therefore, could reduce inputs of harmful chemical pesticides.

And work in the laboratories at Swansea has now shown that the V275 strain of the fungus has potential for use in control programmes as it also kills the adult midge, with some applications in the laboratory having a 100 per cent success rate within five days.

“Now we are at looking at smart ways of using this fungus, trialling different lures  to attract the adult midges to baits contaminated with fungal spores, which will maximise the kill rate, reduce the amount of fungus needed and be very precise in delivering it just to the target insect species,” said Professor Butt.

The IMPACT team, which includes specialists from Forest Research inWales, National University of Ireland, Maynooth and Swansea University, is looking for sites to carry out a series of field trials.

The project team is investigating new ways of tackling a wide variety of important pests which can have a dramatic effect on forests and woodlands across the UK and Ireland.

“The increasing extremes in our weather – hot or cold temperatures, increased rainfall and flooding – are creating the ideal conditions for forest pests,” said IMPACT project leader Professor Hugh Evans of Forest Research in Wales.

“Schmallenburg is a classic example of this interaction between climate and the appearance of diseases in new areas,” he said.

“Until the late 20th century, Europe’s main viral diseases of animals tended to be found in Southern countries, but they are beginning to emerge in northern Europe as we experience warmer weather, which enables the insect vectors to expand their ranges northward.

“For example, it appears that the appearance in Britain of bluetongue virus, carried by midges, is linked to climate change.”

This IMPACT project news item has been posted by Bethan Evans, Swansea University Public Relations Office, Tel: 01792 295049, or email: