Allotrichoma (Allotrichoma) robustum, Mathis, Wayne N. & Zatwarnicki, Tadeusz, 2012

Mathis, Wayne N. & Zatwarnicki, Tadeusz, 2012, Revision of New World Species of the Shore-fly Subgenus Allotrichoma Becker of the Genus Allotrichoma with Description of the Subgenus Neotrichoma (Diptera, Ephydridae, Hecamedini), ZooKeys 161, pp. 1-101 : 46-48

Allotrichoma (Allotrichoma) robustum sp. n. Figs 4550

Allotrichoma laterale of authors, not Loew 1860 [misidentification]. Becker 1896: 121 [generic combination]. Williston 1897: 4 [compared with Allotrichoma abdominale Williston]. Cresson 1942: 108 [list, west coast of United States]. Wirth and Stone 1956: 467 [key]. Wirth 1965: 736 [Nearctic catalog, in part]. Cole 1969: 397 [list]. Mathis and Zatwarnicki 1995: 151-152 [world catalog, in part].

Description.

This species is distinguished from congeners by the following combination of characters: Small to moderately small shore flies, body length 1.55-2.40 mm. Head: Medial facial carina above facial prominence shallow; labella broad, fleshy, shorter than mediproboscis; clypeus microtomentose, usually gray.

Thorax: Presutural supra-alar seta present. Pleural area lacking stripes. Wing with costal vein ratio 0.30-0.31; M vein ratio 0.37-0.42. Legs blackish brown to black; midtibia bearing numerous, erect setae along dorsal surface.

Abdomen: Male 5th sternal flap in lateral view (Fig. 49) moderately shallow, longer posteriorly, bearing several, tuberculate setulae apically; 5th medial process in lateral view (Fig. 49) elongate, conspicuously curved, C-shaped, bearing 4-5 setulae anteroapically. Male terminalia (Figs 45-48): Epandrium in posterior view (Fig. 45) like an inverted, laterally rounded, almost oval U; epandrium in lateral view (Fig. 46) rela tively narrow dorsally, becoming wider ventrally than tapered to a broad point; cercus very robust, in posterior view (Fig. 45) as a elongate, pendulous, ventrolaterally projected process, becoming wider ventrally, apex flared, truncate, bearing numerous, long to very long setulae, very long setulae apicolaterally; cercus in lateral view (Fig. 46) essentially straight, widest subapically, then narrowed to blunt, ventral apex, some very long setulae curved apically or irregularly contorted; surstyli (ventral extensions of epandrium) in posterior view as nearly parallel, shallowly arched medially, narrow processes that bears a few setulae apically, surstylus in lateral view (Fig. 46) conspicuously arched, narrow, very slightly tapered process, not expanded apically; aedeagus in ventral view (Fig. 47) elongate, narrowly ovate, slightly tapered apically, in lateral view (Fig. 48) elongate, narrow, nearly straight; phallapodeme in lateral view (Fig. 48) narrowly triangular, keel narrow, prong-like, shorter than length, almost digitiform; gonite in ventral view (Fig. 47) somewhat bar-like, lateral margin shallowly sinuous, notched basally and medially pointed apically, bearing a subapical, ventral setula and an apical setula; gonite in lateral view (Fig. 47) wide basally, conspicuously but gently curved and tapered toward apex, with a subapical, setula and an apical setula.

Type material.

The holotype male is labeled "Kern Riv. 4 - 1- [19]50 [handwritten by A. H. Sturtevant]/HOLOTYPE ♂ Allotrichoma robustum W. Mathis & T. Zatwarnicki USNM [red]/USNM ENT 00117959 [plastic bar code label]." The holotype male is double mounted (glued to a narrow, paper triangle), is in good condition (abdomen removed, dissected, stored in glycerin in an attached microvial), and is deposited in the USNM. Two paratypes are as follows: UNITED STATES. CALIFORNIA. Kern: Kern River (35°16.1'N, 119°18.4'W), 1 Apr 1950, A. H. Sturtevant (1♂; USNM). Nevada: Sagehen Creek (39°28.6'N, 120°07.9'W), 26 Jun 1974, R. L. Bugg (1♂; USNM). OREGON. Harney: (43°10'N, 119°0.1'W), 29 Jun 1953, A. B. Gurney (1♂; USNM).

Type locality.

United States. California. Kern: Kern River (35°16.1'N, 119°18.4'W).

Distribution.

(Fig. 50) Nearctic: United States (California, Oregon).

Etymology.

The species epithet, robustum, is of Latin derivation and refers to the very robust cerci of this species.

Remarks.

Among Nearctic species of Allotrichoma , Allotrichoma robustum has the most restricted distribution, being thus far known only from the Sierra Mountains in California and Harney County in Oregon.