Small, length about 4-7 mm. Second and third thoracic segments fused. Salivary / silk glands very large.
Head capsule about 1.5 times as long as wide; frontoclypeal apotome present.
Antenna about 1/4 length of head capsule; 5 segmented, with ring organ on proximal third and 2 antennal "setae" on distal third of first segment; antennal blade slightly longer than flagellum; small Lauterborn organs and well developed style present at apex of segment 2.
Labrum with scalloped antero-median margin; SI bifid; SII large, rising from small pedestal; SIII thin, situated posterolaterad to SI and anteriad to SII; S IVA present adjacent to SII, S IVB apparently absent or vestigial. Pecten epipharyngis consists of 3 spines; adjacent first pair of chaetulae laterales of similar shape; one pair of chaetulae laterales with widely expanded base and pectinate margin with one apical blade darker than others; 2 additional smaller, broadly pectinate pairs of chaetulae laterales. Chaetulae basales absent. Premandible with simple apex, with well developed brush near midpoint.
Mandible with 4 inner teeth and with apical tooth usually longer than inner teeth; seta subdentalis extends forward to apex of proximal inner tooth; seta interna with 6-7 plumose branches.
Mentum with 3 median teeth and 5 pairs of lateral teeth, first pair of lateral teeth closely appressed to outer median teeth; ventromental plates vestigial, without beard beneath; seta submenti slightly shorter than mentum length.
Maxilla with lacinial chaetae bladelike, with smooth or fringed inner margins; setae maxillaris simple; galea with group of short setae, without pecten galearis.
Body segments with 0-2 pairs of longer setae, setae longer on posterior segments. Anterior parapods separate, longer than wide, each with some long claws bearing one to several inner spines/teeth, some shorter, stouter, curved claws with inner teeth, and a pair of dark, well sclerotized, hooked claws with expanded bases; a single longer seta near base of each parapod. Procerci small, bearing 4 large apical setae and 2 weak basal setae. Posterior parapods separate, longer than wide, bearing a strong, simple subbasal seta; with simple hooked claws. Anal tubules shorter than posterior parapods.
Tempisquitoneura evidently belongs in the Corynoneura group of genera, but it is unclear how this genus, Onconeura and Thienemanniella are to be distinguished in the larval stages. Evidently the short antenna will distinguish from many species, as will the bifid SI seta and the modified anterior parapod claws. Krestian et al. (2009) tabulate and discuss differentiation of these taxa in relation to American taxa.
The larvae of the only described species, Tempisquitoneura merillorum is phoretic on larvae of Corydalus in streams of north-western Costa Rica (Epler and de la Rosa, 1995). Specimens have been identified subsequently in the southwestern US states of Arizona, primarily within the Gila River drainage, Nevada and Utah (Krestian et al., 2009). In Arizona, Tempisquitoneura occurs at lower elevations considered warm-water with relatively clean substrate (<25% fines in riffle substrates), where it is tolerant of relatively high temperatures, conductivity, elevated pH and hardness.