EPOW - Ecology Picture of the Week

Explanation:   This is not a house fly!  The black stripes on the gray dorsum, the red, foward-pointing compound eyes, the transparent wings with brown veins, and other features identify this insect as a flesh fly.  

The larvae of these common flies scavenge dead animals.  A few flesh fly species are endoparasites of other insects, some take up home in flesh wounds of vertebrates or in the digestive tract of humans, and still others feed on insects stored in bee, ant, termite, or wasp nests.  They usually breed in carrion, excrement, and decaying material, and occur widely.

Some large flesh fly species lay so many eggs that the carcass squirms with the hatched larvae.  

One species of flesh fly (Sarcophaga sarracenia) lays eggs inside leaves of the insectivorous pitcher plant Sarracenia oreophila where the larvae feed on trapped insects.  Then the larvae drill through the leaves, draining the pitcher of its digestive fluids, and then pupate in the soil.  The effect on the plant is not all negative, though, as the fly serves to disperse its pollen.  (And note that the specific epithet -- the "species name" -- of this fly, and the genus name of this pitcher plant, are the same -- "sarracenia" -- suggesting a tight relationship.)

The adults then emerge and seek out nectar, honeydew, and other plant liquids on which to feed, and later return to find their host plant or animal on which to lay its eggs, completing the life cycle.

Flesh flies can be lured to the stinkhorn fungus Phallus impudicus which emits a putrid scent from its fruiting body, thus fooling the fly into dispersing its spores.  

Some flesh flies blend well into their forest surroundings.  

Because of their rapid and well-studied life cycle, flesh flies, along with blow flies and other scavengers, can serve as useful indicators of time of death in forensic investigations, as part of the science of forensic entomology.  Flesh flies and blow flies also can be household pests.

Flesh flies don't bite but you probably wouldn't want one as a pet.