Ocular fringe: in Mallophaga, closely set small hair on posterior half of ocular emargination, sometimes extending on temporal margin.
Ocular lobes: of brain = procerebrum; q.v.
Ocular sclerite: the first or protocerebral segment of the head.
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.
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].
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.