I agree with Paul. O. viridula is characteristic for having pairs of hairbrushes on the ventro-lateral side of the head, and at some point in the movie you may see them. And My experience says that this broad white stripe on the thorax is unique too.
Dank u well, herren
The next days I've found the same kind of larva but much darker and without the white stripe on the thorax.
Another Oplondontha viridula ?
Could be Oplodontha or O. tigrina. The picture (that is the larva) is too dark to be certain. The problem with O. viridula larva is that there are two different colorpatterns (male and female?) a lighter one with this white broad stripe and a darker variant, with only a few smaller yellowish stripes. This colorpattern is almost similar to O. tigrina, but the latter has different hairs on the body and no hairbrushes at the ventral side of the head.
Next week, I will try to catch another one. They share the same size and the same behaviour. How can you cath these airbrush without killing the larva ?
These brushes can be seen in the field even using low magnification. The brushes are about large as the headheight. These brushes are absent in other aquatic Stratiomyds incl. Odontomyia.