Sarcophaga aldrichi
Encyclopedia
The friendly fly or large flesh fly, Sarcophaga aldrichi, is a fly that is a parasitoid
of the forest tent caterpillar
. It strongly resembles the house fly but is in a different family, the Sarcophagidae, or flesh-flies
.. It is a little larger than the house fly, and has the same three black stripes on its thorax
. It has red eyes, a grayish body, and a checkered abdomen.
In early summer it emerges from pupa
e in the ground and seeks out forest tent caterpillar cocoons, where it deposits live larvae which bore into the cocoons and feed on the pupating insects, killing them. Eventually the fly maggot
s drop to the ground and pupate and go dormant over the winter.
Population explosions of it usually occur the summer after the caterpillars are plentiful. The friendly fly can be a real nuisance, but they don't bite, nor do they spread disease. It is sometimes called the "government fly" because when outbreaks of it occur, the rumor goes around that they were released by some government agency in a misguided environmental program.
Parasitoid
A parasitoid is an organism that spends a significant portion of its life history attached to or within a single host organism in a relationship that is in essence parasitic; unlike a true parasite, however, it ultimately sterilises or kills, and sometimes consumes, the host...
of the forest tent caterpillar
Forest tent caterpillar
The Forest Tent Caterpillar Moth is the larva of a North American moth, found throughout the United States and Canada, and most common in the eastern regions....
. It strongly resembles the house fly but is in a different family, the Sarcophagidae, or flesh-flies
Flesh-fly
Flies of the Diptera family Sarcophagidae are commonly known as flesh flies. Most flesh flies breed in carrion, dung, or decaying material, but a few species lay their eggs in the open wounds of mammals; hence their common name...
.. It is a little larger than the house fly, and has the same three black stripes on its thorax
Thorax (insect anatomy)
The thorax is the mid section of the insect body. It holds the head, legs, wings and abdomen. It is also called mesosoma in other arthropods....
. It has red eyes, a grayish body, and a checkered abdomen.
In early summer it emerges from pupa
Pupa
A pupa is the life stage of some insects undergoing transformation. The pupal stage is found only in holometabolous insects, those that undergo a complete metamorphosis, going through four life stages; embryo, larva, pupa and imago...
e in the ground and seeks out forest tent caterpillar cocoons, where it deposits live larvae which bore into the cocoons and feed on the pupating insects, killing them. Eventually the fly maggot
Maggot
In everyday speech the word maggot means the larva of a fly ; it is applied in particular to the larvae of Brachyceran flies, such as houseflies, cheese flies, and blowflies, rather than larvae of the Nematocera, such as mosquitoes and Crane flies...
s drop to the ground and pupate and go dormant over the winter.
Population explosions of it usually occur the summer after the caterpillars are plentiful. The friendly fly can be a real nuisance, but they don't bite, nor do they spread disease. It is sometimes called the "government fly" because when outbreaks of it occur, the rumor goes around that they were released by some government agency in a misguided environmental program.