Arista: a specialized bristle or process on antennae of certain Diptera.
Aristate: Diptera; that type of antennae that bears an arista: = athericerous.
Aristiform: of the form or appearance of an arista.
Armature: applied to the spinous or chitinous processes on the legs, body or wings; or the corneous parts of genitalic structures.
Armatus: set with spines, claws or other chitinous processes.
Armillate: with a ring or annulus of raised or different tissue.
Arolium -ia: cushion-like pads on the tarsi of many insects: one of the lobes of the pulvillus; in Orthoptera, used only for the terminal pad between the claws: see empodium; pulvillus; palmula; plantula; onychium, paronychium, pseudonychium.
Arquate: see arcuate.
Arrhenotokous: capable of producing male offspring only, as in worker bees and some saw-flies.
Arrhenotoky: parthenogenetic reproduction when the progeny are all males: see thelyotoky and deuterotoky.