Ocular tubercles: in Aphids, are a group of prominent facets on the hinder part of each eye. Oculi -us: the eyes: an eye: refers to the compound eyes. Oculocephalic: applied to that pair of imaginal buds destined to produce the cephalic region in Hymenoptera. Odona: toothed: applied to Odonata by Fabricius because of the long teeth on the maxilla and labium. Odonata: net-veined insects with mandibulate mouth; head free; thorax agglutinate; wings similar, elongate, flat; metamorphosis incomplete; copulatory organs of male near base of abdomen, separate from the testes. {Scanner's comment: Dragon flies and damselflies} Odonate: bearing toothed mouth parts, like those of dragon flies. Odoriferous: diffusing an odor; applied to glands or secreting organs. OEcology: see ecology. OEdagus: the penis. OEnocytes: large yellow cells arranged segmentally in clusters, in each side of body cavity: associated with blood and fat bodies. OEsophageal bone: a plate below anterior part of oesophagus in Psocidae. OEsophageal bulb: = sub-clypeal pump; q.v. OEsophageal diverticula: = food reservoirs (q.v.); but more generally applied also to any sac-like structure connected with the gullet. OEsophageal lobes: form posterior portion of brain or tritocerebrum. Oesophageal valve: a funnel-like folding of the oesophagus, extending into the chylific ventricle in some insects, and forming a valve that controls the entrance of food into that organ: = cardiac valvule. Oesophagus: the gullet: that part of the alimentary canal between the mouth and the crop. Olfactory: pertaining to the sense of smell: those lobes of the deutocerebrum from which the nerves supplying the antennae arise. Oligonephria: applied to insects with few urinary (Malpighian) tubes. Oligoneura: having few wing veins: specifically applied in Diptera to Cecidomyids. Olivaceous: with a tinge of olive-green, usually as a shading [olive green]. Omaloptera: the pupiparous flies. Omia: the shoulders: the lateral anterior angles of an agglutinated thorax, when they are distinct:= see umbone: in Coleoptera; a corneous sclerite to which the muscles of the anterior coxa are attached; also the lateral margin of the prothorax; also the lateral margin of the scutellum in Carabids and Dytiscids. Ommateum: the compound eye. Ommatidium -ia: one of the elements of which the compound eye is composed. Omnivorous: a general feeder upon animal or vegetable food, or both. Oncus -i: a welt: applied to welt-like ridges on caterpillars. Onisciform: shaped like a wood-louse, Oniscus sp.; applied to certain Lycaenid and other caterpillars. Ontogenetic: relating to the development of the individual. Ontogeny: the development of the individual as distinguished from that of the species: see phylogeny. Onyches: claws of tarsi.