If you have not already, wash Drosophila larvae 3x with 1ml PBS or other buffer, as appropriate, to remove food, surface bacteria, and other contaminants.
Aspirate the larvae, or remove as much liquid as possible with a pipette.
Place 10 - 300 mg of Drosophila larvae into microcentrifuge.
Add a volume of 0.5mm glass beads (zirconium silicate beads are an appropriate substitute for DNA applications) equal to the mass of tissue. A useful guideline is 100mg ≅ 100μL, as the flies may lie loose in the tube and occupy more volume than they would compressed.
Add 2 volumes of buffer for every volume of sample.
Securely close the microcentrifuge tubes closed and place them into the Bullet Blender®.
Set the Bullet Blender to a speed of 8 and a run time of 3 minutes. Press start.
After the run, remove the tubes from the instrument.
Visually inspect samples, if homogenization is unsatisfactory, run for another two minutes at speed 10.