Oecetis sordida, Blahnik, Roger J. & Holzenthal, Ralph W., 2014

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 : 54-57

Oecetis sordida sp. n. Figs 23, 38, Map 2

Oecetis disjuncta (Banks): Smith and Lehmkuhl 1980: 638 (Figs 1-2, 5, 7, 9-10, 12, 14, 16, 18, 21, 23, 25-26, 29-34, 37-38, 40-41, 43, 45, 46-48, 50); Floyd 1995: 29 (Figs 22A-H, 25) [larval description and distribution, at least in part].

Diagnosis.

This is the species that has been generally referred to in the literature under the name Oecetis disjuncta . As compared to Oecetis disjuncta , which is known to us by only a few specimens from California and Oregon, Oecetis sordida has a very wide distribution, occurring in southern Mexico and over much of the western part of the United States, with records as far east as Michigan ( Smith and Lehmkuhl 1980). The species shows little variation in size, coloration, or genital morphology over this wide range. As defined here, the species can be diagnosed from other species in the Oecetis avara group by its large size, dark brown color, evidently pigmented forewing chord, and by the distinctly deflexed or down-turned apex of the phallobase, which is U-shaped as viewed caudally and has a diagnostic warty ridge (or at least a roughened, rugose texture), preapically on its ventral margin, much as that described for Oecetis verrucula sp. n. Although the overall genitalic morphology of Oecetis sordida is very similar to Oecetis disjuncta , particularly in the shape of the inferior appendages and the angularly bent phallobase, it differs in having much shorter preanal appendages (half the overall length of those in Oecetis disjuncta ), and also by its darker coloration (dark brown with a distinctly pigmented forewing chord, instead of yellowish-brown with a forewing chord unpigmented or only weakly pigmented), and by the presence of the warty ridge on the phallobase, as discussed above, which is absent in Oecetis disjuncta . Oecetis sordida is also somewhat similar to Oecetis apache , sp. n., Oecetis metlacensis , and Oecetis uncata sp. n. especially in size and the general structure of the inferior appendages and phallobase. However all of these species have the apex of the phallobase V-shaped in caudal view, rather than U-shaped, and all are also much lighter in color, yellowish, yellowish-brown, or light brown, rather than dark brown. Oecetis sordida also occurs in sympatry with Oecetis houghtoni sp. n. The 2 could be confused due to their relatively similar coloration and presence in both of a pigmented forewing chord (variably developed in Oecetis houghtoni ). However, Oecetis houghtoni is smaller in size, lighter in color, and lacks either a distinctly angled phallobase or preapical wart on the structure. Additionally, it possesses an asymmetric phallic sclerite, absent in Oecetis sordida .

Adult.

Forewing length: male (11.0-12.5 mm), female (9.8-10.6 mm). Color medium to dark brown, legs slightly paler, palps grayish brown, overall appearance somewhat “hoary” due to intermixed paler setae. Antennae very pale brown with indistinct, narrow annulations at intersection of antennomeres. Forewing spots small and indistinct, spots at base of discal and thyridial cells and base of fork V most noticeable, more or less V-shaped (confined to base of fork); veins of forewing chord distinctly pigmented and relatively widely spaced, s and r-m veins usually slightly closer; apical spots, at apices of major veins absent or very inconspicuous. Setae along veins in apical part of forewing semi-prostrate, laterally diverging, not conspicuous due to relatively dense setae on membrane. Fringe of setae along costal margin of forewing short, dense, decumbent.

Male genitalia.

Segment IX very short, with elongate setae along posterolateral margin. Tergum X with narrow, deflexed mesal lobe, lobe very short, tapering apically, apex with small sensilla; lobe continuous basoventrally with paired lateral membranous projections. Preanal appendage relatively short, length about 2 1/2 times maximum width, simple in structure, apical setae elongate. Inferior appendage with very prominent rounded dorsal lobe and scarcely projecting ventral lobe, separated from dorsal lobe by shallow, rounded notch; posterior margin of ventral lobe, as viewed ventrally, with rounded bend near base, lobes very weakly diverging; basomesal projection of appendage forming very weakly developed projection with short, stiff setae; dorsal lobe with very stout, ventrally-projecting setae on anterior margin, longer, finer setae on posterior margin and mesally-curved setae on dorsal margin, mesal surface with stout, ventrally curved setae. Phallobase relatively short, ventral apex strongly, angularly deflexed, bend close to apex, apex distinctly sclerotized, ventral surface with distinct rugose region preapically (Figs 23B, D), rugose area often somewhat raised as bur or wart; ventral apex, as viewed caudally, broadly U-shaped (Fig. 23C). Phallotremal sclerite prominent, basally forming relatively large tubular collar, ventral margin projecting; asymmetrical lateral sclerite absent.

Holotype.

Male (pinned): USA: South Dakota: Lawrence Co., Black Hills National Forest, Boxelder Creek, 1.8 mi W Nemo, 44°11.846'N, 103°32.024'W, el 1470 m, 11.viii.1994, Holzenthal & Huisman (UMSP) (UMSP000065014).

Paratypes.

MEXICO: Chihuahua: Riito, Hwy 16, 10 mi E Yepachic, 23.vi.1987, B. Kondratieff & R.W. Baumann, 1 male (pinned) (NMNH); Durango: 10 mi. W El Salto, 9000 ft. 1.vii.1964, J.E.H. Martin, 1 male (pinned) (NMNH); Oaxaca: 1 mi NE of Ixtlan de Juarez, 13.viii.1967, O.S. Flint, Jr., 1 male (pinned) (NMNH); Mexico: Temascaltepec, Real de Arriba, 2.vi.1990, A. Rojas, 2 males (pinned) (UMSP); USA: Arizona: Oak Cr. Canyon, 18.vi.1968, Flint & Menke, 1 male (pinned) (NMNH); Apache Co., Little Colorado R., Greer, 34°01'N, 109°45'W, el 2530 m, 13.viii.1995, C.M. & O.S. Flint, Jr., 1 male (pinned) (NMNH); Apache Co., W Fork Black River, F.R. 68 @ West Fork Campground, 33°46.676'N, 109°24.291'W, el 2438 m, 18.vi.1999, D.C. Houghton, 38 males (pinned) (UMSP); Apache Co., W. Fork L. Colorado River, end of F.R. 575, nr. Greer, 33°59.627'N, 109°27.890'W, el 2713 m, 16.vi.1999, D.C. Houghton, 1 female (pinned) (UMSP); Apache Co., S. Fork L. Colorado R., F.R. 560 @ South Fork Campground, 34°04.690'N, 109°24.629'W, el 2347 m, 27.vi.1999, D.C. Houghton, 2 males (pinned) (UMSP); Apache Co., W. Fork Black R., F.R. 68 @ West Fork Campground, 33°46.676'N, 109°24.291'W, 2438 m, 18.vi.1999, D.C. Houghton, 5 males (pinned) (UMSP); same except 19.vi.1999, D.C. Houghton, 21 males (alcohol) (UMSP); Apache Co., Apache-Sitgreaves National Forest, San Francisco River, Luna Lake spillway., FR. 570, nr. Luna Lake campground, 33°49.678'N, 109°04.855'W, el 2408 m, 28.vi.1999, D.C. Houghton, 1 female (alcohol) (UMSP); Greenlee Co., Apache-Sitgreaves National Forest, Blue R. @ F.R. 281, 7 km SE Upper Blue Campground, 33°39.807'N, 109°06.507'W, el 1768 m, 20.vi.1999, D.C. Houghton, 34 males (alcohol), 2 males (pinned) (NMNH); Greenlee Co., Apache-Sitgreaves National Forest, Blue River @ F.R. 475, Blue Range Primitive Area, 33°17'N, 109°11'W, el 1280 m, 21.vi.1999, D.C. Houghton, 1 male (pinned), 1 male (alcohol) (UMSP); Minnesota: Lake Co., shore Lake Superior, at Split Rock, 1.vii.1935, D.G. Denning, 1 male (pinned) (UMSP); Lake Co., W. Fork Split Rock River, County Road 03, 47°14.333'W, 91°29.000'W, 21.vii.2001, D.C. Houghton, 5 males (alcohol) (UMSP); Cook Co., Cascade Creek, Cascade River S.P., Superior Hiking Trail, 47°42.500'N, 90°31.666'W, 9.vii.2001, D.C. Houghton, 1 male (alcohol) (UMSP); Washington Co., Valley Creek, Belwin Station., 44°55.000'N, 92°47.667'W, 15.vii.2001, D.C. Houghton, 2 males (alcohol) (UMSP); St. Louis Co., shore Lake Superior at Split Rock, 1.vii.1935, D.G. Denning, 1 male (pinned) (UMSP); South Dakota: same data as holotype, 1 male (pinned) (UMSP); Montana: Beaverhead Co., Beaverhead National Forest, Pettengill Cr., 9.7 mi S Wise River, 45°40.843'N, 113°03.606'W, el 1930 m, 6.viii.2006, Holzenthal, Blahnik, Robertson, Huisman, 1 male (pinned) (UMSP); Beaverhead Co., Beaverhead National Forest, Big Hole River, W of Divide on State Hwy 43, 45°45.400'N, 112°46.850'W, 25.vi.2002, R.J. Blahnik, 11 males, 6 females (pinned) (UMSP); Wyoming: Sublette Co., Half Moon Lake, 42°56'N, 109°45'W, el 2315 m, 24.vii.1995, C.M. & O.S. Flint, Jr., 1 male (pinned) (NMNH); Sublette Co., Bridger Teton National Forest, Half Moon Lake, 42°55.857'N, 109°44.462'W, el 2130 m, 24.vii.1995, Holzenthal, et al., 1 female (pinned) (UMSP).

Etymology.

This species is named Oecetis sordida from the Latin word sordidus, used in Botanical and Zoological literature to describe a dull, dirty, or muddy hue, and referring here to the dark color of the wings of this species.