"Sucker" - what is it, definition of the term
The term denotes the specialized feeding apparatus of blood‑feeding arthropods such as ticks, true bugs, lice, and fleas; it comprises a piercing element—often a stylet or a pair of interlocking plates—that creates a conduit for fluid intake, employing muscular action to generate suction and draw host fluids into the insect’s digestive system.
Detailed information
Ticks, bugs, lice and fleas are hematophagous arthropods that rely on specialized mouthparts to extract blood from hosts. Their feeding structures are adapted for piercing skin and maintaining a fluid channel, allowing continuous ingestion while preventing clotting.
The primary components of the ingestive apparatus include:
- Mandibles or stylets – needle‑like elements that penetrate epidermis and reach capillaries.
- Salivary glands – secrete anticoagulants, vasodilators and anesthetics to facilitate smooth flow.
- Siphon or tube – a narrow conduit that transports the liquid from the wound to the digestive tract.
Ticks possess a hypostome equipped with barbs that anchor the parasite during prolonged feeding periods lasting days. Their salivary secretions contain proteins that suppress host immune responses, ensuring an uninterrupted blood supply.
Bugs (e.g., bedbugs) use a beak‑like rostrum formed by elongated stylets. The rostrum operates like a syringe, delivering saliva that contains anticoagulant compounds before drawing blood in short, intermittent bouts lasting minutes.
Lice have a streamlined head with a pair of slender mandibular stylets. These penetrate the superficial layers of skin, and the insect’s foregut functions as a direct channel for blood uptake, typically completed within a few hours of attachment.
Fleas feature a robust, piercing‑sucking proboscis. The mouthparts can breach the host’s fur and skin, and rapid, high‑frequency feeding enables the flea to ingest several microliters of blood per minute. Their saliva contains enzymes that inhibit clot formation and reduce inflammation.
All four groups share a common evolutionary solution: a set of hardened, retractable structures that create a sealed pathway for fluid intake while delivering pharmacologically active saliva. This design maximizes feeding efficiency and minimizes detection by the host.