What does a bed bug bite with? - briefly
A bed bug bite results from the insect injecting saliva that contains anticoagulant and anesthetic proteins. The saliva provokes localized itching, redness and swelling.
What does a bed bug bite with? - in detail
Bed bugs obtain a blood meal through a set of highly adapted mouthparts located at the tip of the elongated labium. The labium houses a pair of slender stylets that function as a composite piercing‑sucking apparatus. Each stylet consists of a mandible‑like structure for cutting tissue and a maxilla‑like structure that forms a canal for saliva delivery and blood uptake.
Key components of the feeding apparatus include:
- Labium that supports the stylet bundle
- Two mandibular stylets that create a tiny incision
- Two maxillary stylets that form separate channels for saliva and blood
- Salivary glands that produce a complex fluid mixture
- Muscular pump that generates suction
The feeding sequence proceeds as follows. The insect detects a host’s heat and carbon‑dioxide, positions the labium against the skin, and drives the mandibles into the epidermis. Simultaneously, the maxillae open to release saliva into the wound. The saliva contains anticoagulants to prevent clotting, anesthetic compounds that mask the bite, vasodilators that increase local blood flow, and enzymes that facilitate digestion. After a brief injection, the insect creates a negative pressure within the maxillary canal, drawing blood upward through the same channel for ingestion.
The saliva’s pharmacological components explain the typical reaction at the bite site: a small, erythematous papule that may develop into a raised, itchy wheal. The delayed onset of itching results from the anesthetic effect, which allows the insect to feed undisturbed for several minutes before the host perceives the irritation.