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January 20, 2012

Aphid Eating Flower Fly Found in North Campus

There are over 150,000 species of flies in the world! Most visitors who come to the Museum can name only a few of these flies (house fly, horse fly, or mosquito for examples) and many hold the belief that we would be better off without flies in our world. On Wednesday, January 18, we found a fly that I am sure will help you realize that all flies can't be cast as "bad" characters I introduce the humble aphid eating flower fly, Eupeodes volucris.

Female Eupeodes volucris
Photo taken by Jerry Friedman

Why do people like these flies and not others? This isn't an easy question to answer, but I'll have a go... First of all, these flies eat aphids and as any gardener will tell you, aphids are a serious garden pest. Secondly, they belong to a family of flies known as flower flies so called for their proclivity to visit flowers and suck down nectar. Thereby they play a role in pollination. Finally, if you look closely at these small flies you'll see why a lot of geeky people, like myself, think they are quite beautiful. Not only are they brightly colored and highly patterned, when their eyes catch the sunlight just right they have an iridescent sheen! Although I might add that E. volucris isn't as flashy as its close relative, the aptly named stripe-eyed flower fly, Eristalinus taeniops, also a native to the Los Angeles area.

Stripe-eyed flower fly
Photo courtesy of What's That Bug website
How does a fly eat an aphid? It is actually the larval stage of the fly, or maggot that chows down on aphids. Much like immature ladybugs they trawl through a sea of aphids on a plant and chomp any that get in their way!  Though they don't have quite the same look as a ladybug! 
Flower fly maggots eating oleander aphids
Photo courtesy of What's That Bug website
To find out more our local flower flies, swing by the Museum gift shop to get a copy of our latest entomological publication, Flower Flies of Los Angeles County.
Flower Flies of Los Angeles County
Thanks to Brian Brown and Jim Hogue for supplying fly information and identifying the fly specimen.



Posted by:Lila Higgins

Comments

Urbpan...I should send you a copy of our Flower Fly publication. Send me your mailing address via FaceBook!

Very nice! I love the flies in my yard, there are so many different kinds. I'm fortunate in that the only biting flies I've encountered here have been the mosquitoes. I think long-legged flies are my favorite, followed by hover (flower) flies. Most of our flower flies are bee or wasp mimics for some reason.