From Paul Tritschler:

This campaign was hardly subtle, with the enemy depicted as bugs. Magazines carried cartoons showing Italians, Germans and Japanese as part cockroach, and prior to the mass incendiary bombing of Japanese cities, the US Marines’ magazine Leatherneck displayed a cartoon of a half-human, half-insect creature entitled Louseous Japanicas to accompany an article that called for “enemy breeding grounds to be completely annihilated.”