How do bed bug larvae feed? - briefly
Bed bug nymphs pierce the skin of a sleeping host with a hollow mouthpart, inject saliva that prevents clotting, and then draw liquid blood through the same tube. They feed repeatedly, each molt requiring a new blood meal to progress to the next developmental stage.
How do bed bug larvae feed? - in detail
Bed‑bug nymphs are obligate blood feeders. Upon locating a host, a nymph climbs onto exposed skin and inserts its piercing‑sucking mouthparts, the stylet bundle, into the epidermis. The stylet consists of a central food canal and two lateral canals that deliver saliva. Salivary secretions contain anticoagulants, vasodilators, and anesthetic compounds, preventing clot formation and reducing host perception of the bite.
Feeding proceeds through the following steps:
- Host detection – thermal, carbon‑dioxide, and kairomone cues guide the nymph to a suitable area.
- Attachment – the insect secures itself with claws and adhesive pads.
- Penetration – the stylet pierces the skin, reaching a capillary.
- Saliva injection – anticoagulant proteins keep blood fluid; anesthetic agents blunt the host’s response.
- Blood ingestion – the nymph draws blood through the central canal, typically consuming 1–5 µL per meal, depending on instar size.
- Detachment – after engorgement, the nymph withdraws the stylet and retreats to a hideout to digest.
A single meal does not provide enough nutrients for development; each instar requires a blood intake before molting to the next stage. The interval between meals varies with temperature and host availability, ranging from several days at optimal temperatures (≈27 °C) to weeks under cooler conditions. Digestive enzymes break down hemoglobin, and excess water is excreted as a dry, dark fecal spot.
Repeated feeding cycles are essential for growth: first‑instar nymphs may need three to five blood meals before reaching the second instar, while later instars require progressively larger volumes. The cumulative blood intake across five nymphal stages typically equals the adult’s single meal, illustrating the species’ reliance on frequent, small blood acquisitions throughout development.