By spring or early summer the grub is full grown and forces its way out of the skin, falling to the ground, into which it burrows for a short distance and transforms into the pupal stage.
"Special Report on Diseases of Cattle"
U.S. Department of Agriculture J.R. Mohler
The mature flies then emerge from the pupal envelope and are soon ready for egg laying.
"Special Report on Diseases of Cattle"
U.S. Department of Agriculture J.R. Mohler
From the pupal stage the mature fly emerges.
"Special Report on Diseases of Cattle"
U.S. Department of Agriculture J.R. Mohler