Black Striped Litter Fly

In the hot dry weather the spiders and insects have mostly vanished. There are the very busy bumblebees and a few blowflies, but little else. I found this tiny litter fly sipping nectar from  carrot flowers. I have called it a black striped litter fly because it is black compared with the brown striped litter fly. This is the only colour I see here. The brown one is called Sapromyza neozelandica, but I can find no information on the black one.