The Insecticons were a group of Decepticon Transformers toys that transformed from a robotic insect to a robot. There were two kinds, both introduced as toys in 1985, called "Insecticons" and "Deluxe Insecticons" on the toy boxes.
The smaller Insecticons are the ones usually referred to by Transformers fans, since only they were used in the Transformers cartoon. There were three, Bombshell, Shrapnel, and Kickback, and their toys were produced by Takara, the same company that licensed the Dinobots (and most of the other early Transformers) to Hasbro. They were introduced in the episode "A Plague of Insecticons", where they were revealed to be Decepticons who had landed on Earth separate from their teammates millions of years ago. They had adapted to life on Earth by adopting forms which could live by ingesting matter rather than relying on energon.
The Deluxe Insecticons were licensed to Hasbro from Bandai, a toy company who was still in competition with Takara in Japan. Since the American cartoons were also broadcast in Japan, it was decided that the Deluxe Insecticons would be omitted from the cartoon. The toys suffered a corresponding lack of interest and sales. The Deluxe Insecticons were Barrage, Chop Shop, Ransack, and Venom.