Suspensi: the chrysalids of butterflies that are suspended by the tail only: see succincti.

Suspensoria: are those muscles or ligaments that hold the viscera and other internal structures in place.

Sustentors: the two posterior projections of a butterfly chrysalis.

Suture: a seam or impressed line indicating the division of distinct parts of body wall: the line of junction of elytra in Coleoptera.

Suturiform: an articulation soldered together so that only a slight impressed line is visible.

Swarming: the concerted departure from a hive of a large number of worker bees, accompanied by a queen; this forming the nucleus of a new colony.

Swimmerets: gill or plate-like structures in the aquatic larvae of some Neuroptera, serving as oars or organs of locomotion.

Swimming paddles: terminal appendages of mosquito pupae.

Swoked: smoky, suffused with gray or blackish.

Sylvan: species inhabiting forests or woodland areas.