F F 1 First filial generation, arising from a cross, subsequent generations abbreviated F 2 , F 3 , etc. see P 1 . face n. [L. facies, countenance] 1. The surface of anything. 2. (ARTHRO: Insecta) The front of a verticle head between the compound eye | F F 1 First filial generation arising from a cross subsequent generations abbreviated F 2 F 3 etc. see P 1 . face n. L. facies countenance 1. The surface of anything. 2. ARTHRO Insecta The front of a verticle head between the compound eye above the mouth to vertex. a. In Hymen-optera between antennae and clypeus. b. In Diptera below the frontal suture often having grooves or fovea below the antennae the mesofacial plate. c. In Ephemeroptera the fused front and vertex facies. facet n. F. facette small face 1. A small surface. 2. ARTHRO Insecta The external surface or part of a compound eye unit or ommatidium. facette n. F. facette small face ARTHRO Pentastomida A funnel-shaped opening through the inner membrane complex of the egg into which the product of the dorsal organ is deposited. facetted eye see compound eye facial angle ARTHRO Insecta The angle formed by the point of union of the face and vertex. facial bristles see oral vibrissae facial carina ARTHRO Insecta One of the carinae of the frontal costa and of the accessory carinae of the face. a. In Orthoptera one of the accessory carinae. b. In Diptera the single median facial ridge separating the antennal grooves. facial depression ARTHRO Insecta 1. The antennal groove. 2. For Diptera the middle of the face the facial plate. facialium see vibrissal ridge facial orbit ARTHRO Insecta On the head the region next to the mesal margin of a compound eye. facial plate ARTHRO Insecta In Diptera the central part of the face. facial quadrangle ARTHRO Insecta In bees the quadrangle Online Dictionary of Invertebrate Zoology 353 formed by the eyes laterally and between their apex and below by a line between their lower points. facial ridge see vibrissal ridge facies see face facio-orbital bristles ARTHRO Insecta In Diptera bristles on each side near the orbit may extend to the gena or cheek orbital bristles. see genal bristles. factor n. L. facere to do to make 1. An agent or causative agent in genetics determining .
