Why do bedbugs need blood? - briefly
Bedbugs ingest vertebrate blood because it provides the essential proteins, lipids, and carbohydrates needed for their growth, molting, and egg production. Their physiology lacks the enzymes to digest other food sources, making blood their sole viable nutrient.
Why do bedbugs need blood? - in detail
Bedbugs (Cimex lectularius) are obligate hematophagous insects; they cannot complete their life cycle without ingesting vertebrate blood. Their digestive physiology lacks the enzymes required to break down plant or detrital matter, so blood supplies the sole source of nutrients needed for growth, molting, and reproduction.
The blood meal provides:
- Proteins and amino acids for synthesis of structural cuticle, enzymes, and reproductive tissues.
- Lipids that serve as energy reserves and are incorporated into egg yolk.
- Carbohydrates in the form of glucose, supporting immediate metabolic demands.
- Micronutrients such as iron, calcium, and vitamins that are scarce in alternative diets.
During each nymphal stage, a bedbug must obtain a fresh blood meal to trigger ecdysis. The hormonal cascade that initiates molting is activated by the rise in hemolymph protein levels following ingestion. Failure to feed results in arrested development and eventual mortality.
Adult females require multiple blood meals to produce viable eggs. The volume of blood taken correlates with fecundity; larger meals increase the number of oocytes matured and improve hatch rates. Blood also supplies the osmotic balance necessary for egg formation, preventing desiccation of developing embryos.
Physiologically, bedbugs possess a specialized foregut equipped with a thin cuticle that minimizes water loss while allowing rapid ingestion of up to 7 µL of blood in a few minutes. Their salivary glands secrete anticoagulants and anesthetic compounds, ensuring uninterrupted feeding and efficient nutrient acquisition.
In summary, blood fulfills all macronutrient and micronutrient requirements for development, molting, and reproduction, and it provides the biochemical triggers essential for the species’ life‑history processes. Without this exclusive diet, bedbugs cannot survive or propagate.