How do the mouthparts of Anoplura differ from those of chewing lice?

The mouthparts of Anoplura (sucking lice) and chewing lice (suborders Amblycera and Ischnocera) are fundamentally different in structure and function, reflecting their distinct feeding habits.12

• Anoplura (Sucking Lice): These insects possess specialized piercing-sucking mouthparts. They feature three fine, eversible stylets enclosed in a sheath within the head, which are used to pierce the host's skin to feed exclusively on blood. They also possess a small proboscis armed with recurved, toothlike processes that help hold the skin during feeding, and a strong pump associated with the esophagus to facilitate blood intake.123
• Chewing Lice: These lice possess mandibulate (biting) mouthparts adapted for chewing. They feed on materials such as feathers, skin debris, secretions, and sometimes blood or tissue fluids, rather than piercing the skin to draw blood directly. Their mandibles are designed for gnawing, and they lack the specialized stylets and sucking pumps found in Anoplura.2431

While most lice fall into these categories, the suborder Rhynchophthirina is an exception, possessing modified mandibles borne at the end of a long proboscis.12