Trito-cerebral segment: see second antennal segment.
Trito-cerebrum: the posterior portion of the brain, formed by the ganglion of the third primary segment; also termed labro-frontal lobe.
Tri-undulate: with three waves or undulations.
Triungulin: the first larval stage of a meloid beetle.
Trivial: applied to a name, means specific as opposed to generic, or popular as opposed to technical.
Trivittate: with three stripes or vitta.
Trochalopoda: Heteroptera in which the posterior coxae are nearly globose and the articulation is a ball and socket joint: see pagiopoda.
Trochanter: a sclerite, sometimes divided, between the coxa and femur sometimes fused with the femur.
Trochanterellus: see apophysis.
Trochantine: the basal part of the trochanter when it is two-jointed: in Coleoptera, a piece often present on the outer side of and sometimes movable on the coxa; also the small sclerite connecting the coxa with the sternum in Dytiscidae: in Neuroptera and Trichoptera the posterior separated part of the coxa: in Orthoptera, a narrow longitudinal sclerite between mandible and gena.