Monday, November 07, 2005
2 UFoIs (Unidentified Flies of Interest)
This is a small fly I've seen hanging out on tagetes flowers; specifically tagetes lemonii and tagetes lucida. It perches or walks around on the flower buds, sometimes twisting its wings forward in what I figure is a mating display (haven't seen 'em mating, though). The wing pattern puts it in the "picture window fly" group (Tephritidae); based on some checking around the web, I think it's either genus euaresta or neotephritis. Both of these groups lay eggs in the developing seeds of plants in the composite family. Euaresta bella looks a lot like my fly but supposedly does not occur in California. Euaresta stelligera is found here but breeds exclusively on ambrosia (ragweed). 12/2009: But most likely it is Trupanea nigricornis, based on info found at Arthropods of OC, et al.
It's tempting to assume this is a blow fly, maybe black blow fly phormia regina except in the blow flies there is a much wider separation between the eyes. It would be nicer if this weren't a blow fly.