Assurgent: down-curved at base, then upcurved to an erect position.
Asymmetrical: not alike on the two sides; not symmetrical.
Asymmetry: a state of unlikeness in lateral development; absence of symmetry in form or in the development of members.
Ater: deep black; not shining.
Aterimus: the deepest black.
Athericerous: see aristate.
Atom -us: a minute dot or point.
Atomarius: with minute dots or points.
Atrachelia: Coleoptera in which there is no visible constriction between head and prothorax: Rhynchophora and some Heteromera.
Atrium: a chamber just within the spiracle and before the occluding structure to the trachea.