The black soldier fly is a widespread fly whose larvae are commonly found in compost heaps. Larvae are also sometimes found in carrion. This is fascinating as they are able to break down animal matter where other composting techniques fail.
When the larvae have completed their larval development, they enter a stage called “prepupae” wherein they cease to eat, they empty their gut, their mouth parts change to an appendage that aids climbing, and they seek a dry, sheltered area to pupate. This migration instinct is utilized by grub composting bins to self-harvest the mature larvae. These containers have ramps or holes on the sides to allow the prepupae to climb out of the composter and drop into a collection area.
Black soldier fly larvae (BSFL) may be used in manure management, for house fly control and for the bioconversion of organic waste material. Mature larvae and prepupae raised in manure management and waste bioconversion operations may also be used to supplement animal feeds. The larvae are highly efficient in converting proteins, containing up to 42% of protein, and a lot of calcium and aminoacids. In 432 hours, 1 gram of black soldier fly eggs turns into 2.4 kilograms of protein.
Larvae are sold as feeders for owners of chickens, herptiles and tropical fish, or as composting grubs. They store high levels of calcium for future pupation which is also beneficial.