Roderick Rose was an entomologist obsessed with transforming the human race into a derivative of insects. As such, he used his perverted science to transform himself into a grasshopper-like creature known as Hellgrammite. Gaining enhanced strength, tremendous leaping ability as well as secreting adhesives and weaving cocoons to ensnare his prey.
Another man on Earth-Two used similar science to transform himself into the Yellow Wasp, although his obsession was more in line when obtaining wealth for himself. Perhaps this was due to his desire to exercise dominance over the insect world, specifically on wasps which his chemically controlled. He possessed wings allowing him to glide, and a stinger gun.
Back on Earth-One, Hellgrammite first came in contact with his superhero foes in the form of Batman and the Creeper, who upended his schemes. Years later, he returned to duel with Black Canary and Green Arrow, ending in the same results.
As for Yellow Wasp, his perpetual opponents were Wildcat and his sidekick Stretch Skinner, and after three chronicled quarrels with the pair the Wasp apparently retired, as in his last caper the Furious Feline had knocked off the enhanced vision mask of the fiend revealing his true identity, if in appearance only.
There would be other bad boy bugs to appear, but none quite as creepy as these two.