Celery-fly

Male "winter" Celery-fly (Euleia heraclei)

This little fly (which measures only about 1/4 inch from "nose" to "tail") is a Celery-fly. There have been loads of them in the garden of late, standing on leaves and waggling their patterned wings at each other. This one is a male, as indicated by his smoothly rounded backside; a female would have a pointy bit at the back end for laying eggs with. The flies are undoubtedly loving the masses of Alexanders (a close relative of Celery) that we have sprinkled throughout the garden and that run rampant in the surrounding countryside. The female lays her tiny eggs into a Celery (or Alexanders) leaf, and the minute larvae grow up munching their way between the leaf's two surfaces — "mining", as it were.

There are a number of small "picture-winged" flies in Britain. This one has non-continuous bands which split at the back edge of the wing. Some of the flies we're seeing are jet black, while others are a reddish-brown (and a few are half and half). Apparently, the colour is temperature-dependent, with "winter flies" being darker than "summer flies". The books say those bright green eyes turn red when the fly dies, but given that I've seen more than one flying around with bright red eyes, I'm not sure they've got that 100% right. We'll apparently be seeing these flies until November. They're widespread all across Britain, and are considered agricultural pests, due to their habit of attacking the leaves of Celery, Parsnip and other related species. But here in our garden, we don't care what they do to the Alexanders!

Another male; this one half-"winter", half-"summer"