Sucking pump: in sucking insects, a thick-walled muscular enlargement of the oesophagus that serves to draw up the liquid food = pharyngeal pump.

Sucking spears: the mandibles and maxillae of Hemerobiid larvae, used for puncturing prey and sucking its juices.

Sucking stomach: a thin-walled muscular pouch connected with the end of the oesophagus; serves as a food reservoir and is not commonly present except in some Lepidoptera.

Suctoria: an ordinal term proposed for fleas.

Suctorial: adapted for sucking: see haustellate.

Suctorial vesicles: bladder-like structures connected with the oesophagus in mosquitoes supposed to assist in blood-sucking; but this is disputed.

Suffused: clouded or obscured by a darker color.

Suffusion: a clouding, or a spreading of one shade over another.

Sulca: grooves, furrows or channels: plural of sulcus.

Sulcated: grooved; furrowed with broad, concave, parallel impressed lines.