Microphorella bifida sp. nov.

urn:lsid:zoobank.org:act: 9E930F53-FBF6-4ECF-864C-3182FD66343D

(Figs 17–20, 25–28, 101)

Type material. HOLOTYPE, ♂ (Fig. 17) labelled: “RiversideCAL| 17 Mar. 35 | ALMelander”; “ ALMelander | Collection| 1961”; “HOLOTYPE| Microphorella | bifida | Brooks & Cumming” [red label] (USNM) . PARATYPES: USA: California: Riverside County: same data as holotype [33°58'N 117°22'W] (4♂, 1♀, USNM); same data as holotype except, CNC1155804 (1♂, USNM); same data except, 10.ii.1935 (1♂, 1♀, USNM); same data except, 22.ii.1935 (6♂, 1♀, USNM); same data except, CNC1155806 (1♂, USNM); same data except, 24.ii.1935 (15♂, 8♀, USNM); same data except, 10.iii.1935 (2♂, 3♀, USNM); same data except, 2.v.1935 (1♀, USNM); same data except, 5.v.1935 (1♂, USNM); same data except, 25.v.1942 (1♀, USNM); same data except, 10.iv.1944 (1♂, 1♀, USNM); same data except, 11.iv.1951 (6♂ mounted as pairs on three pins, USNM) .

Other material examined. USA: Arizona: Mohave County: Littlefield [36°53'14"N 113°55'47"W], B-9 1931, 27.iii.1931, Chrysothamnus speciosus, 2018, CNC1155831 (1♂, USNM). California: Fresno County: 10 mi. E Mercy Hot Springs [36.7044°N 120.8595°W], 25.iii.1985, L.G. Bezark (1♂, UCDC). Monterey County: Arroyo Seco Campground [36.2359°N 121.4816°W], 26.iv.1998, M. & P.H. Arnaud, Jr, CNC487295 (1♂, USNM); Carmel Valley, Hastings Natural History Reservation [36.3795°N 121.5626°W], ca 1750 ft, 19.vi.1998, P.H. Arnaud, Jr & M.M. Arnaud, Arnaud Flight Trap over Big Creek, Collection No. 01958-A (1♂, 2♀, USNM); same data except, CNC487293 (1♀, USNM); same data except, 20.vi.1998, Collection No. 01959-A (1♀, USNM); Paraiso Hot Springs [36.3314°N 121.3688°W], 13 km SW Soledad, 400 m, 20/ 21.iv.1974, P.H. Arnaud, Jr (2♀, USNM); same data except, 28.v.1977 (1♂, USNM); same data except, 29.v.1977 (1♀, USNM); same data except, 30.v.1977 (2♀, USNM). Riverside County: Agua Caliente Indian Reservation, Palm Canyon [33°46'N 116°34'W], 2.iv.1980, P.H. Arnaud, Jr (2♂, 1♀, USNM); Cathedral Canyon [33°45'N 116°32'W], 3.iv.1945, A.L. Melander (2♂, 1♀, USNM); Indio [33°43'N 116°13'W], 21.iii.1955, W. R. Richards (2♂, 1♀, CNC); Mg. Spr. Can. nr Indio [33°43'N 116°13'W], 5.iv.1945, A.L. Melander (1♂, USNM); 1000 Palms Oasis [33°50'N 116°18'W], Thousand Palms, 30.iii.1955, W. R. Richards (1♂, CNC); same data except, CNC1155827 (1♂, CNC). San Diego County: Julian [33°04'N 116°36'W], 5.v.1945, A.L. Melander (2♂, USNM). Stanislaus County: Frank Raines Co. Park [37°25'N 121°22'W], Del Puerto Canyon, 15.v.1971, M. Wasbauer, CNC1155824 (1♂, CSCA). Ventura County: Wheeler’s Sprgs [34.5084°N 119.2915°W], 15.vi.1948, W.W. Wirth (1♂, EMEC).

Diagnosis. Males of this species can be distinguished from other members of the M. acroptera species group by the following combination of characters: acrostichal setae well-developed, biserial; hind basitarsus without basiventral spur-like seta; halter dark brown (Fig. 17); hind trochanter with tubercle cylindrical or weakly clavate (Fig. 18); face with sides subparallel; hypandrium large and bulbous (Figs 18, 25, 26); dorsal lobe of surstylus with pair of prensisetae (1 disc-like, 1 blade-like, Figs 25, 26); cercus with bifid lateral lobe (Fig. 28).

Description. Male (Figs 17–19, 25–28): Wing length 1.7–2.0 mm. Similar to M. acroptera except as follows: Head (Fig. 17): Face and clypeus slightly broader, broader than 2× width of anterior ocellus; antenna with arista-like stylus shorter, 1.25–1.3× length of postpedicel. Thorax: Acrostichals biserial, with well-developed rows extending to prescutellar depression; 7–9 dorsocentrals; area laterad dorsocentrals more extensively covered with small setae. Legs: Hindleg: Trochanter with tubercle cylindrical or weakly clavate with rounded apex (Fig. 18), apical spine-like seta with sharply pointed tip; femur sometimes with anteroventral row of setae longer than femur width, especially basally. Wing: As in description of M. acroptera . Abdomen (Fig. 18): Blackish with weak metallic green tinge. Sternite 5 with broad ventral projection (Fig. 19), narrower basally with more developed lateral lobes, bilobate or trilobate (with medial lobe present). Hypopygium (Figs 18, 25–28): Left epandrial lamella (Fig. 25) with ventral epandrial process roughly uniform in width, apex bifid, divided into a pair of similar claw-like processes, medial surface lacking projection. Dorsal lobe of left surstylus with broad, truncate dorsolateral lobe bearing 2 prominent prensisetae (upper one disc-like, lower one blade-like) and 1 long posterior seta; medioventrally with tubercle bearing sinuous seta and broad adjacent lobe. Ventral lobe of left surstylus as long as dorsal lobe, somewhat flattened, curved medially, apex slightly broader bearing 5 setae. Right epandrial lamella (Fig. 26) with dorsal lobe of surstylus broad and truncate (similar to left side), bearing 2 prominent prensisetae (upper one disc-like, lower one blade-like), 1 lateral seta near ventral prensiseta and 1 posterior seta. Ventral lobe of right surstylus as long as dorsal lobe, medially curved at base with apex projecting dorsally and somewhat clavate, with several setae on posterior surface. Phallus (Figs 26, 27) long and convoluted, with curving tubular basal portion, inflated and protruding middle portion (with small dentiform process on outer surface), tapering into relatively short tubular apical portion. Cercus (Figs 25, 26, 28) with bifid lateral lobe projecting dorsally from cercal base, outer process of lobe conical and half as long as clavate inner process which bears several prominent setae; with rounded flap-like medioventral lobe.

Female (Fig. 20). Similar to male except as follows: Head: Face and clypeus slightly broader, broader than 2.5× width of anterior ocellus; antenna with arista-like stylus slightly shorter, about 1.15× length of postpedicel. Legs: Hindleg: Trochanter without tubercle bearing apical spine-like seta; femur without prominent anteroventral row of setae. Abdomen: As in description of M. acroptera .

Distribution and seasonal occurrence. This new species is known from northwestern Arizona and also California, from Stanislaus County south to San Diego County (Fig. 101). Specimens were collected from February to June.

Etymology. This species is named for the diagnostic bifid structure of the male cercus (Fig. 28).

Remarks. This species appears to be closely related to M. sinuosa sp. nov., with which it shares very similar hypopygial morphology, especially in the structure of the dorsal surstylar lobes, phallus and cercus (Figs 25–28, 52–55).

Males from the northern part of the species range in California (i.e., Arroyo Seco Campground, Carmel Valley, 10 mi. E Paraiso Hot Springs, Mercy Hot Springs and Del Puerto Canyon, Fig. 101) have longer anteroventral setae on the hind femur. However, the hypopygial morphology of this northern group appears similar to that of the specimens from the southern part of California and Arizona that have shorter anteroventral setae on the hind femur.