Tuesday, June 22, 2010

Flies in the Backyard, part 2

Two weeks ago, I posted about some of the flies I found in the backyard. Here are a few more. The one pictured above is a blow fly, probably a Common Green Bottle Fly (Lucilia sericata). This is a very common species, recognized by its metallic coloration and the pattern of hairs on its thorax. According to Wikipedia, the larvae of this species are sometimes used for maggot therapy. Lucilia sericata is also one of several species that help establish how long a corpse has been dead, since the flies lay their eggs and the larvae develop in a predictable sequence. When not scavenging at corpses, blow flies can be useful pollinators.

The second species is a Syrphid fly, probably Toxomerus marginatus. Syrphid flies mimic bees and wasps, but do not carry a sting. You can tell the difference between bee mimics and real bees by the number of wings (two for flies instead of four for bees) and the shape of their antennae. Like other Syrphid flies, Toxomerus marginatus is an important pollinator. Adults are often found around flowers.

The last species for this post is a soldier fly, Ptecticus trivittatus. These flies are often found around compost piles.