Not all beekeepers do this, but the general practice is one that embodies the attitude that living things are mere material and have no intrinsic value of their own other than what commercial value we can wrench from them. Artificial insemination involving death of the male is now also the norm for generation of new queen bees. The favoured method of obtaining bee sperm is by pulling off the insects head.
Decapitation sends an electrical impulse to the nervous system which causes sexual arousal.
The lower half of the headless bee is then squeezed to make it ejaculate. The resulting liquid is collected in a hypodermic syringe.