What is the life cycle of a bed bug and what does it feed on? - briefly
Bed bugs develop through an egg stage, five successive nymphal instars, and reach adulthood, with each molt requiring a blood meal. They subsist solely on the blood of humans or other warm‑blooded animals.
What is the life cycle of a bed bug and what does it feed on? - in detail
The common bed bug (Cimex lectularius) undergoes a simple, incomplete metamorphosis consisting of five distinct developmental phases: egg, first‑instar nymph, second‑instar nymph, third‑instar nymph, fourth‑instar nymph, fifth‑instar nymph, and adult. Each stage, except the egg, is a nymph that must obtain a blood meal before molting to the next instar. The complete cycle from oviposition to reproductive adult typically spans 4–6 weeks under optimal temperature (25–30 °C) and humidity (70–80 % RH), but can extend to several months in cooler conditions.
- Egg: Female deposits 1–5 eggs per day, attaching them to crevices near host resting sites. Eggs are about 1 mm long, whitish, and hatch in 6–10 days.
- First to fifth instars: Each nymph measures 1.5–4 mm after successive molts. After each blood ingestion, the insect expands its cuticle and sheds it. Molting intervals lengthen with each stage, ranging from 3–5 days (early instars) to 7–10 days (later instars).
- Adult: Fully wingless, 4.5–5.5 mm long, capable of reproducing after a single blood meal. Females can lay 200–500 eggs over a lifetime of 6–12 months, depending on environmental conditions.
Feeding behavior is obligate hematophagy. Bed bugs locate hosts by detecting carbon dioxide, body heat, and kairomones. They insert a beak‑like proboscis into the skin, inject anesthetic and anticoagulant saliva, and ingest up to 7 µL of blood per meal. Feeding typically occurs at night when hosts are immobile; a single meal sustains the insect for several days to weeks, depending on the developmental stage. Nymphs require a blood meal to progress to the next molt, whereas adults need a meal to produce eggs. After engorgement, the insect retreats to a concealed harbor to digest the blood, during which the abdomen expands visibly.
Environmental factors influence both development speed and feeding frequency. Temperatures above 30 °C accelerate development but may reduce survival; temperatures below 15 °C markedly slow metabolism, extending the interval between meals to weeks or months. High relative humidity improves egg viability and nymphal survivorship, while low humidity increases desiccation risk.
In summary, the organism’s life history comprises an egg stage followed by five molting nymphal phases, each dependent on a blood meal, culminating in a reproductive adult that continues the cycle. Feeding is strictly blood‑based, triggered by host cues, and essential for growth, molting, and reproduction.