Stylostome

The stylostome is a funnel or channel-like structure formed in response to trombiculid mites. The formation is not caused by the mouthparts of the mites, because these mites do not have needle-like mouthparts as other hematophagous animals have been known to have, but have chelicerae, which only pierce the skin. The tube is formed by the digestive enzymes in the saliva, which is the same salivary secretions that break down cells that is causing the surrounding tissue to harden. As the mite feeds longer, the saliva seeps farther down, and digesting more tissue, therefore causes the stylosome to penetrate to lower layers of skin.