Missouri FFA Entomology CDE Practice Exam

The key idea is recognizing fleas as Siphonaptera with piercing-sucking mouthparts adapted for feeding on blood. Fleas are wingless, laterally flattened ectoparasites whose mouthparts form a beak-like structure that pierces host skin and sucks blood. The other insects listed have chewing mouthparts: flea beetles and flour beetles chew plant material, and the forage looper (a caterpillar) chews leaves. So the flea is the only option that is both in Siphonaptera and uses sucking mouthparts.