A new study has revealed that a lucky 15% of the population produces their own midge repellant. Researchers from Aberdeen University and Rothamsted Research studying the feeding habits of the Scottish biting midge found that those were spared bites produced a specific mixture of two chemicals, geranylacetone and methylheptenone. The researchers hope that the results will eventually lead to the developement of a new repellant based on these chemicals.
The research was conducted during peak midge season and involved over 300 contestants and spectators at the Loch Ness Duathlon. It also found that tall men and larger women with a high body mass index were more likely to be bitten than smaller people. The researchers say that this may be because midges naturally fly at the height of the taller men and therefore found them first and that larger people are easier for midges to find and that they may produce more heat and carbon dioxide which attracts midges. The study sample did not include sufficient large men for the results to be conclusive but the researchers suggest that the findings would apply equally to men.
It is estimated that in some parts of Scotland, one single hectare of land may host up to five biting midges for every man, woman and child in Scotland – or 25 million biting midges per hectare.