Midges: Pests or saviours?
“And on the 8th day, Adam approached God and said “Are you quite sure about midges?””
Ah the midges, the cause of many legends and frantic running in the highlands of Scotland.
The cold start to the year and the unseasonably warm end to the year have dramatically changed the midge lifestyle. The beginning of the year saw a decline in midges compared to 2014 numbers which is extremely rare. The topsy-turvy seasons though have resulted in a third hatching of midge larva in 2015, an unusual occurrence as normally there are only two hatching events. So what does this mean?
A scan of the headlines suggests that we should all hide underground for the year but the numbers tell a different story. The third hatching is very small and, despite it, the number of midges is likely to be down considerably. Based on trap results, in Argyll alone experts estimate that there were two million less midges than last year and overall there are only about two thirds as many midges. It all seems like good news for humans as midges reputedly cost Scotland around two hundred million pounds due to scaring tourists away. However midges have a variety of uses and their decline may have wider implications.
Midge larvae live in water and are a vital part of the ecosystem. They are a key prey source for frogs, toads and fish and so a decline in midges means a decline in food for these animals which has a knock on effect up the food chain. The larvae feed on a range of organic detritus making them important “recyclers” as they convert dead material into growth, meaning energy is not being lost from the food chain. The adults are also prey to huge numbers of species, such as spiders and birds.
Possibly a bigger implication is that it means there may be more people. It has been proven that midge abundance directly links to house prices and tourism meaning that they really do control human distribution. Midge are no threat at all to the countryside but humans tend to cause trouble wherever they go and so more human activity is not really a cause for celebration. As one comment on a news article put it:
“This is the loveliest part of the world but completely ruined by the midge. Many people like myself are eventually forced to sell up and move south because they can no longer cope with the bites”.
I have no sympathy with this viewpoint as the reason the area is “lovely” is due primarily to the lack of humans in the first place. It seems like a little victory for the midges over the human invaders, after all, they were there first.
Scientifically though they are also useful. Midge larvae consume algae and are used as a bio-indicator. When the water is polluted with agricultural chemicals the algae increases and so do midge numbers. Essentially more midge larvae indicates more pollution. The larvae are also being research as they may be indicators of anti-biotic resistance in microbial populations.
So there we have it, the humble and irritating midge is actually a vital cog in the food chain whilst also keeping humans from overpopulating rural areas and indicating water pollution. None of what is written will help if you are attacked by midge swarm though, then you are on your own.
As the saying goes, “There are only two stages of a midge attack. When you think you might die, and when you are afraid that you won’t.”
13,355 total views, 3 views today