Oecetis elata Denning & Sykora

Blahnik, Roger J. & Holzenthal, Ralph W., 2014, Review and redescription of species in the Oecetis avara group, with the description of 15 new species (Trichoptera, Leptoceridae), ZooKeys 376, pp. 1-83 : 30-32

Oecetis elata Denning & Sykora Figs 9, 43, Map 3

Oecetis elatus [sic] Denning & Sykora, 1966: 1225 [holotype male: Mexico, Veracruz, Almilinta (locality not found), CAS].

Oecetis elata Denning & Sykora: Flint et al. 1999: 135.

Diagnosis.

Oecetis elata is readily distinguished from any other species in the Oecetis avara group by its small size and dark coloration. As viewed through a stereomicroscope, the body color is almost black and the wings dark brown, giving the species a blackish or fuscous color as viewed generally. In genital morphology Oecetis elata is probably most similar to Oecetis sordida . However, the apex of the phallobase, while being distinctly and strongly deflexed, is flexed more nearly in the middle. Like Oecetis sordida , the basal sclerites anchoring the phallobase, the phallocrypt, are very heavily pigmented and distinctly visible (Fig. 9C). However, Oecetis elata is much smaller in size than Oecetis sordida and the 2 are not likely to be confused. The angular process on the dorsal lobe of the inferior appendage, as figured and mentioned in the original species description by Denning and Sykora, is somewhat misleading as a diagnostic character. The dorsal lobe of the inferior appendage is actually broadly rounded, as in other members of the Oecetis avara group, but the posterior margin is noticeably folded inward, sometimes abruptly enough to give the margin of the appendage, in lateral view, the appearance of being angular. This character, while evident in the type specimen, is not generally characteristic of the species. The apparent absence of a mesal lobe of tergum X (in material examined) is unusual for species in the Oecetis avara group and may also prove to be diagnostic.

Adult.

Forewing length: male (7.3-7.8 mm). Color medium brown (dark brown as viewed without magnification). Antennae light brown. Forewings without spots, veins of forewing chord not contrastingly pigmented, chord moderately spaced, s and r-m veins generally rather closely spaced, m widely spaced. Setation of forewings relatively uniform; setae along veins in apical part of forewing mostly apically directed, not or only slightly laterally diverging Fringe of setae along costal margin of forewing dense, short, not strongly projecting.

Male genitalia.

Segment IX very short, with elongate setae along posterolateral margin. Tergum X with mesal lobe absent (in specimens examined), but with short, paired lateral membranous projections (not figured). Preanal appendage moderately elongate, length about 4 times maximum width, simple in structure, some apical setae elongate. Inferior appendage with prominent rounded dorsal lobe and weakly projecting ventral lobe; dorsal lobe with posterior margin distinctly, but rather weakly, mesally incurved; projection of ventral lobe rounded apically, obtusely angled; ventral margins of ventral lobes, as viewed ventrally (Fig. 9F), not diverging at base, rounded apically; basomesal projection of appendage scarcely projecting, with few stiff setae; dorsal lobe with stout, mesally-curved setae on dorsal margin and stout, ventrally-curved setae on mesal surface. Phallic shield, surrounding phallobase, very distinctly sclerotized. Phallobase relatively short, strongly ventrally curved at about middle, apex distinctly sclerotized; ventral apex, as viewed caudally, broadly U-shaped. Phallotremal sclerite prominent, basally forming short tubular collar, ventral margin projecting, apex acute; asymmetrical lateral sclerite absent.

Material examined.

MEXICO: Puebla: L. Alchichicha, 19-20.vii.1965, Flint & Ortiz, 29 males (pinned) (NMNH).