The good side of midges is explored at www.sciencedaily.com/releases/2017/03/170317132648.htm ... ecologists have been studying midges in Wisconsin and Iceland. There are 15,000 lakes in Wisconsin and a third of the State lies within 200m of a lake or stream. Biting midges terrorise tourists and walkers in western Scotland (and horse flies in England) - so what use are these insects?
Iceland is situated on the edge of the Arctic Circle and swarms of midges rise out of a lake in the north of the island every spring and summer, so much so they seem to darken the sky and impair breathing (it is alleged). However, populations of midges can crash in some years, hence the research in order to understand why this happens. In every year the numbers seem to fluctuate. What is interesting is that midges hatching out on the lake fertilise the surrounding landscape (when they die and fall to the ground). This provides nutrients to the thin soil which otherwise is a poor growing medium. It causes grasses to grow and Icelandic shepherds and farmers harvest the 'midge grass' to feed their flocks etc. Midges have a use in this world it would seem.