Supra-alar cavity: = supra-alar groove.

Supra-alar depression: in Diptera = supra-alar groove.

Supra-alar groove: in Hymenoptera, a groove or depression just above the base of wings: in Diptera, a groove on the meso-thorax just above the root of the wings.

Supra-a.n.a.l: situated above the a.n.u.s.

Supra-a.n.a.l hook: in male of most Lepidoptera, a curved hook attached to the plate covering the genital cavity: = uncus.

Supra-a.n.a.l plate: a triangular sclerite covering the a.n.a.l cavity above; present in many insects, sometimes in one s.e.x only, often in both: see a.n.a.l operculum.

Supra-cerebral: applied to that pair of salivary glands situated above the brain in bees.

Supra-clypeal mark: in bees; a patch of light color above the clypeus.

Supra-clypeus: = post-clypeus; q.v.: = nasus.

Supra-Oesophageal: situated above the oesophagus: applied to two large ovoid ganglia so situated, and connected by a short, thick commissure; - the brain.

Supra-orbital: situated above the eye.

Supra-spinal: above the spine or nerve cord: applied to a cord or band of connective tissue lying above the central nervous system in adult Lepidoptera also to a sinus or vessel acting as a ventral heart.

Supra-spiracular line: in caterpillars, margins the spiracles superiorly.

Supra-stigmatal line: = supra-spiracular lines.

Supra-triangular cross-veins: in Odonata, cross the supra-triangular s.p.a.ce.

Supra-triangular s.p.a.ce: in Anisoptera, an area just above the triangle, occupying nearly the same position as the quadrilateral of Zygoptera: hyper-trigonal s.p.a.ce.

Sura.n.a.l: = supra-a.n.a.l.

Sura.n.a.l plate: the middle dorsal plate attached to the l0th abdominal segment of the male gra.s.shoppers, above the a.n.a.l opening: a supra- a.n.a.l tergite of a caterpillar.

Sursum: directed upwardly.

Suspensi: the chrysalids of b.u.t.terflies 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 b.u.t.terfly 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.

Symbiogenesis: the method of origin of social symbiotic relation among ants and other insects.

Symbiosis: a life relationship existing between different kinds of animals or plants, or between animals and plants: true symbiosis is where both parties to the relation benefit: see also parasitism, commensalism. Among the ants social symbiosis exists in its most highly developed form and distinctive terms have been proposed for the various types of relations:

Calobiosis, is that a.s.sociation in which one species, often only the female, lives in the nest of and at the expense of another species, either for a time, = temporary - or altogether, = permanent calacobiosis. {Scanner's note: sic}

Cleptobiosis, is where one species of ant lives in or near the nest of another, preying upon its larvae or pupae or stealing the food supply.

Dulosis, is that mingling of colonies which owes its origin to the enslavement of one species by another.

Hamabiosis, is that relation where two species of any insects, one of which may be an ant, live side by side without obvious motive or known advantage to one or both.

Lestobiosis, is where the workers of one ant colony "hold up" those of another species and rob them of the food they are carrying to the nest.

Parabiosis, is where different species of ants form colonies with inosculating galleries, and have their households strangely intermingled, but not blended.

Phylacobiosis, is the relation existing between ants and Termites, the ants living in the doorways of the Termites and functioning as guards.

Synclerobiosis, is an a.s.sociation of two species of ants that usually inhabit independent colonies, for purposes that are not clearly understood.

Trophibiosis, is the relationship between ants on the one hand and aphids, coccids and the like on the other; these species being sought and attended by the ants for their own benefit: see myrmecophily.

Xen.o.biosis, is where one species of ant lives as a guest in the nest of another, maintaining its own household, and mingling freely with the host species, the two living on terms of mutual toleration.

Symbiotic: species that live together in a state of symbiosis.

Symmetrical: evenly developed on both sides.

Symmetry: that regular arrangement of organs or parts which is capable of division into similar halves or similar radii.

Sympathetic nervous system: applied to the nerves and ganglia of the alimentary ca.n.a.l and sonic other viscera which they innervate; = vagus; visceral nervous system.

Symphily: the relation borne to ants by the true guests which inhabit their nests and are fed and tended: rendering in return some substance or service desired by the ants: see metochy and synechtry.

Symphyla: a group name for apterous species resembling myriapods in appearance, with functional abdominal legs and the genital openings on the last abdominal segment: regarded by some as connecting forms between insects and myriapods, e.g.

Scolopendrella.

Symphysis: where two sclerites are joined together by a soft membrane, permitting a slight motion.

Synaptera: originally wingless insects without metamorphosis; the Thysanura.

Synarthrosis: an articulation without motion.