This particular kind of the insect through clear associations was connected with such notions as 'one who lives on the labor of others', 'an idler', 'a sluggard'. These associations underlie the transfer of the meaning to an aircraft which was steered by remote control without a pilot. Initially, pilotless aircraft were used as air targets for training AA gun crews. These targets were marked with black stripes along the tail part of the fuselage. Hence, the nickname.
Drones are program-guided while RPVs are piloted from a distance by operators.
It is curious to know that bomber air crews called jokingly air gunners 'drones'. Probably because air gunners were idle during flights and had only lots of things to do when firing at enemy fighters. This word is now a term. Its principal meanings are 'date limits', 'state of disrepair'. Deadline' in jails meant the line in the yard where prisoners used to walk beyond which they had not to go.