How do domestic bed bugs feed on blood? - briefly
They insert a needle‑like proboscis into the skin, secrete saliva containing anticoagulants and anesthetic, and then draw blood. The feeding episode typically lasts a few minutes before the insect retreats to digest the meal over several days.
How do domestic bed bugs feed on blood? - in detail
Domestic bed bugs (Cimex lectularius) obtain blood through a specialized, multi‑stage process that begins with host detection and ends with digestion of the ingested meal. The insect relies on a combination of sensory cues, morphological adaptations, and biochemical secretions to complete each phase efficiently.
The feeding sequence can be broken down into distinct steps:
- Host location – Thermoreceptors detect body heat, while chemoreceptors sense carbon‑dioxide and skin odors. These signals guide the bug toward a suitable feeding site.
- Attachment and probing – The bug climbs onto the host’s skin and inserts its elongated, beak‑like mouthpart (the labium) into the epidermis. The stylet bundle, consisting of two maxillary and one mandibular needle, pierces the skin to reach a blood vessel.
- Salivary injection – Saliva is released into the wound before blood intake. It contains anticoagulants (e.g., apyrase), vasodilators, and anesthetic proteins that prevent clotting, expand the capillary, and reduce the host’s perception of the bite.
- Blood uptake – Negative pressure generated by the bug’s cibarial pump draws blood through the stylets into the foregut. Ingestion typically lasts 5–10 minutes, during which the insect can fill its abdomen to nearly twice its resting volume.
- Meal processing – Blood is stored in the midgut, where proteolytic enzymes break down hemoglobin and other proteins. The bug excretes excess water and salts via the Malpighian tubules, concentrating the nutrient load.
- Post‑feeding behavior – After engorgement, the insect retreats to a concealed harbor, where it digests the meal over several days before seeking another host.
Key anatomical features that facilitate this process include the elongated rostrum, which allows deep penetration; the serrated mandibles that cut tissue; and a highly expandable abdomen that accommodates large blood volumes. The combination of sensory detection, rapid proboscis deployment, and pharmacologically active saliva enables bed bugs to feed efficiently while minimizing host reaction.