Wormaldia planae Ross and King

Muñoz-Quesada, Fernando J. & Holzenthal, Ralph W., 2008, Revision of the Nearctic species of the caddisfly genus Wormaldia McLachlan (Trichoptera: Philopotamidae), Zootaxa 1838, pp. 1-75 : 53-56

Wormaldia planae Ross and King

Figures 101–107, 129

Wormaldia planae Ross and King , in Ross 1956: 38, 40, 61, 64, figs. 75 A, B, 123 A, B, 130, male, Chiapas, Mexico (INHS); Flint 1968: 9, figs. 10, 11; Flint 1971: 20, figs. 17, 18; Flint 1981: 10, figs. 14, 15; Flint 1991: 31, figs. 47, 48; Flint 1995: 7–8; Fischer 1971: 195; Bueno-Soria & Flint 1978: 194 (distribution); Holzenthal 1988: 58 (distribution); Aguila 1992: 535 (distribution); Botosaneanu 2002: 91 (distribution).

This species was placed within the W. arizonensis Group, as defined by Ross (1956) (Table 1).

This species can be distinguished from the other Nearctic species of this genus by the shapes of tergum VIII and segment X. Tergum VIII in W. planae has two conspicuous lateromesal processes posteriorly that enclose a broad U-shaped mesal emargination. Tergum X is complex and subtriangularly elongate with various lobate processes anteromesally and lateromedially, with the apex having a triangular appearance. Some specimens examined showed a slight morphological variation in the shape of the posterior margin of tergum VIII from that of the holotype. In those specimens examined, the two lateromesal processes are slightly shorter, and the U-shaped mesal emargination is shallow. The new records of W. planae in Arizona result in a new Nearctic distribution for this species; its previously distribution was typically Neotropical.

Adult (in alcohol). Length of male forewing 4.5– 5 mm. Head light brown, and with lighter setae. Antenna long, slender, yellowish, with small, lighter setae. Maxillary palps yellowish, with lighter setae. Labial palps yellowish, with lighter setae. Dorsum of thorax brown. Legs yellowish, with small, lighter setae. Forewing yellowish, covered with fine, small, light brown setae, with apical forks I, II, III, IV, and V present ( Fig. 106). Hind wing translucent, with very few fine, small, brown setae, with apical forks I, II, III, and V present ( Fig. 107).

Male genitalia ( Figs. 101–105). Sternum VII straight posteriorly without process mesally. Tergum VIII with two conspicuous, stout, knob-shaped, lateromesal processes posteriorly that fence a broad, deep, U-shaped, mesal emargination; when viewed laterally, posterodorsal corner with rounded apex of posterolateral process. Sternum VIII relatively straight or very weakly convex posteromesally. Segment IX, when viewed dorsally, concave anteriorly; when viewed laterally, broad, nearly subrectangular in appearance, convex anteriorly, very weakly sinuous posteriorly; when viewed ventrally, weakly concave anteriorly, very shallowly sinuous posteriorly with shallow, mesal concavity. Segment X, when viewed dorsally, subtriangularly elongate, bearing anteromedially Y-shaped and mesal process strongly elongate, reaching middle of tergum, lateromedially with obtusely triangular process elongate and widest basally, projected laterally, with apex of tergum triangular in appearance, with lobate projections laterally and anteromesally; when viewed laterally, convexly extended dorsomedially, concavely curved preapicodorsally, subovally elongate apically with oval projection. Superior appendages digitate; when viewed dorsally, parallel with segment X, stout, elongate; when viewed laterally, shorter than segment X, subovally elongate posteromedially. Inferior appendages two segmented; when viewed laterally, basal segment stout, rectangular, strongly elongate, broadest and convex medially, apical segment stout, rectangularly elongate, shorter (about 0.9 times) and narrower than basal segment, weakly concave ventromedially, subovate and wide posteriorly; when viewed dorsally, apical segment stout, rectangularly elongate, subovate and wide posteriorly, with elongate and apicolateral patch of short, thin, black, spine-shaped setae; when viewed ventrally, basal segments paired, united for about their anterior three-fifths, separated posteromesally by a deep and U-shaped emargination, each basal robust, widest medially, with outer margin convexly curved; apical segment as when viewed dorsally. Phallus, when viewed laterally, pistol-shaped, widest basally, tapering from middle to apex, membranous apically, very lightly sclerotized, with two visible, internal sclerites ( Fig. 105).

Material examined. USA: Arizona: Gila Co. - Yavapai Co.: Line Fossil Creek , 30.viii.1986, A.R. Brigham & M.W. Sanderson, 1 male (in alcohol, INHS) ; Fossil Creek, Rd. 708, SE Camp Verde, 3–4.vi.1981, M.W. Sanderson, 2 males, 4 females (in alcohol, INHS) ; Yavapai Co: Beaver Creek, Ejct. 17–179, 9– 10.v.1984, M.W. Sanderson, 1 male (in alcohol, INHS) ; same except, 14–15.v.1984, 1 male (in alcohol, INHS) ; ca. 2 mi [= 3.2 km] N Camp Ground , 23.v.1987, M.W. Sanderson, 1 male, 2 females (in alcohol, INHS) ; bellow outlet of Montezuma Well , 29–30.viii.1985, M.W. Sanderson, 1 male (in alcohol, INHS) ; stream ex. Chas. Ward Ranch, Rd. 618, 19–20.v.1984, M.W. Sanderson, 1 male (in alcohol, INHS) .

Distribution: Mexico: Chiapas. USA: AZ (new record).