Midge species capable of carrying virus
University discovery will help gauge speed bluetongue could spread
Published:
FOUR of the midge species in Scotland that could potentially carry the deadly bluetongue virus can now be identified for the first time.
The discovery by scientists from Aberdeen University is seen as important as it gives statisticians working for the Scottish Government the information they now require to gauge the speed at which the virus might spread if it reaches Scotland.
Further research work at the Institute of Animal Health at Pirbright in Surrey is ongoing to find out if the four species of the Culicoides obsoletus midge family – chiopterus, dewulfi, obsoletus ss and scoticus – that have been found north of the border are capable of carrying a virus that over the last two years has devastated livestock production across mainland Europe and left farmers nursing millions of pounds of losses.
In southern Europe a different midge family – Culicoides imicola – is responsible for transmitting the various strains of the virus that originates in Africa.
But the worsening virus situation in northern Europe has shown that other midge families now also carry it.
Scotland's Culicoides obsoletus family has already been implicated as a carrier and the work at Pirbright is attempting to find out if its member species can transmit bluetongue. The Aberdeen researchers identified the possible bluetongue carriers among 1million midges that were captured in 37 light traps set up on farms from the Borders to Thurso by Edinburgh-based Advanced Pest Solutions at the end of last year and early 2008.
They used a pioneering DNA bar-code test developed by the university to identify all the midges captured and produce a map of where all the different species are.
The Aberdeen team found actual midge numbers were dependent on climatic and geographic conditions, with some species favouring warmer conditions and others colder.
University ecologist Jane DeGabriel said: “This is the first large-scale study of the distribution and abundance of Scottish midge species. Our findings provide vital information for assessing the risk of bluetongue being transmitted in Scotland and the effects of climate change on the spread of this and other animal diseases.”
The midge work has been funded by the Scottish Government.
NFU Scotland has, meanwhile, urged Scottish farmers to avoid importing any livestock from France. It has declared the country a no-go area because of the worsening bluetongue situation. More than 8,000 new cases of the BTV-8 strain have been declared this summer and 200 of the BTV-1 strain.
