Grassfly species Thaumatomyia sp
This family of small to extremely small flies is also known as Swarming Flies, Eye Gnats and Frit Flies. There are many almost identical species within this group, most of them black and yellow. Between the true eyes the ocelli (secondary eyes) take up a lot of space. Most species are hairless. They often go about unnoticed, because of their size. The real big species may reach one centimeter, but most species, like the one in the pictures, reach some 3 or 4 millimeters only. The only time ordinary people notice them is when they appear in a swarm, often comprised of tens of thousands of animals. The larvae live in and on the roots of grasses, including cultivated grasses and grains. The larvae of most species hunt for aphids. Some other species are treated as pests. The animal in the pictures was photographed in early spring. It is a Thaumatomyia species and could very well be Thaumatomyia notata, the best known species, which may swarm in very big numbers. Our pictures however are not good enough to be sure. Thaumatomyia hallandica and Thaumatomyia trifasciata are extremely similar. Add to this the fact that Thaumatomyia notata is extremely variable and you know you're in trouble. The two animals in the pictures could even be two separate species!
