you got midgies wow are you in Scotland?
if they are really midgies they wont hurt your plants theyre carnivores the little bastards fly in the millions and bite you all over and then follow you everywhere for your blood. although its usully only the females that bite so the males? but i dont think so
if you have any problems with unwanted pests try putting some garlic in there some how (the vampire myth is true anything that eats blood hates garlic)(in fact pretty much any beastie hates garlic) also maybe try putting a geranium in there if you like natural insect repellent) or just get bug off or raid if you cant be botherd and just wanna killem.
now i heard RAID insect repellant was carcinogenic that means it has carbon right? does that mean although its bad for us it might not be bad for the plant, perhaps even good? or too many other chemicals?
p.s could just be fruit flies maybe try putting a bowl of not so new fruit (smells more) in another room to attract them. just an idea.