Microphorella cornuta sp. nov.

urn:lsid:zoobank.org:act: 22EA5D5B-EF93-47F2-A373-E6DFED45CEEC

(Figs 76, 77, 79, 80, 103)

Type material. HOLOTYPE, ♂ labelled: “ U.S.A.: CALIFORNIA:| SanMateoCounty, Por-| tola Valley, Alpine| Road, CorteMaderaCr|eek 24-VI-1984 230m | Paul H.Arnaud, Jr. ”; “[upper margin with row of asterisks]| Flight trap in| shaded creek bed,| 1315–1615 hours DST| [lower margin with row of asterisks]”; “HOLOTYPE| Microphorella | cornuta | Brooks & Cumming” [red label] (USNM) . PARATYPES: USA: California: Contra Costa County: Briones Reg. Park [37°57'N 122°08'W], Toyon Canyon, 25.v.1979, D.D. Wilder (5♂, 9♀, CAS) ; same data except, 26.v.1979 (2♀, CAS) . Marin County: Tocaloma [38°03'01"N 122°45'34"W], 13.v.1962, L.R. O’Brien (1♂, CMNH) . Napa County: Oakville [38°26'N 122°24'W], 180 ft, 25.iv.1971, P.H. Arnaud, Jr (1♂, USNM) . San Mateo County: Corte de Madera Cr. nr Portola [37°23'N 122°19'W], 3.vi.1954, P.H. Arnaud (1♀, USNM) ; same data except, 31.v.1958 (1♀, USNM); Corte de Madera Ck, 19.vi.1965, J.D. Birchim (1♀, CAS) ; Corte de Madera Crk, Alpine Rd, SE of Portola, 19.v.1968 (1♀, USNM) ; Portola Valley, Alpine Road, Corte de Madera Crk, 230 m, 12.vi.1965, P.H. Arnaud, Jr (2♂, 1♀, USNM) ; same data except, 26.v.1968 (1♂, USNM); same data except, 12.vi.1983 (3♀, USNM); same data except, 13.vi.1971, P.H. Arnaud, Jr & M.M. Arnaud (1♂, 10♀, USNM); same data except, 3.vi.1983, flight trap over creek, sun/shaded, 1310–1450 hours, air temperature 76 F, water 62.5 F, P.H. Arnaud, Jr (2♂, 3♀, USNM); same data as holotype (3♂, 4♀, USNM); same data except, CNC1155802 (1♂, USNM); same data except, flying low over water of creek, 1430–1500 hours DST, P.H. Arnaud, Jr (1♂, 1♀, USNM); same data except, 30.vi.1984, flight trap, creek bed, 1300–1730 hours, P.H. Arnaud, Jr (16♂, 20♀, USNM) .

Diagnosis. In addition to the characters listed above for the M. acuminata lineage, males of this species can be distinguished from other members of the M. acroptera species group by a combination of hypopygial features (Figs 79, 80), including the short, thick, horn-like process of the phallus arising near mid-length, the long, narrow apical projection of the left postgonite, the emarginate tip of ventral epandrial process and the protruding, emarginate lower margin of the right postgonite.

Description. Male (Figs 76, 77, 79, 80): Wing length 1.6–1.7 mm. Similar to M. acuminata sp. nov. except as follows: Thorax: Dull and more intensely bronze pruinose, with distinct metallic blue tinge. Legs: Dark brown with dark brown setae. Wing: As in description of M. acroptera . Abdomen (Figs 76, 77): Sternite 5 with posteromedial projection subtriangular. Hypopygium (Fig. 76, 77, 79, 80): Left epandrial lamella with ventral epandrial process uniformly wide, apex emarginate. Dorsal lobe of left surstylus elongate, straight and narrow with expanded apex. Ventral lobe of right surstylus (Fig. 80) bifurcate, with short outer lobe and longer medial lobe, both bearing a few setae. Left postgonite lobe with long, narrow apical projection (Fig. 79). Right postgonite with posterior margin of protruding basal process concave, apical portion with unevenly bifurcate apex (Fig. 80). Phallus robust with short, thick, horn-like process arising near mid-length that ends well before phallic tip (Fig. 79).

Female. Similar to male except as follows: Legs: Hindleg: Trochanter without tubercle bearing apical spine-like seta; femur without distinct anteroventral row of setae. Abdomen: As in description of M. acroptera .

Distribution and seasonal occurrence. This new species is known from the San Francisco Bay Area of central California (Fig. 103). Specimens were collected from April to June.

Etymology. This species is named in reference to the diagnostic horn-like process of the phallus (Fig. 79).