Margaret Humphrey & Stella Crossley
(Photo: courtesy of Andrew Mertens, Northern Territory)
These grubs are not true Caterpillars, but are the larvae of flies of the family STRATIOMYIDAE.
They can occur in huge numbers in compost. They are large, dry, and rather hairy for a fly maggot . Curiously: the size of the fly which emerges from them after pupation is much smaller than the larva.
Some people do not like the larvae in their compost, but they are just as good as earth worms at breaking down organic waste, and also make good chook food.
The adult flies have prominent porrect antennae, and only two wings, each with a concave inner margin.
(updated 26 November 2008, 17 March 2014)