Paracoenia (Paracoenia) wirthi Mathis

Mathis, Wayne N. & Marinoni, Luciane, 2016, Revision of Ephydrini Zetterstedt (Diptera: Ephydridae) from the Americas south of the United States, Zootaxa 4116 (1), pp. 1-110 : 24-27

5. Paracoenia (Paracoenia) wirthi Mathis

Figs. 27–34 , Map 5

Paracoenia (Paracoenia) wirthi Mathis 1975: 78 [ United States. California. Inyo: Tecopa Hot Springs (1.6 km N); HT ♂, CAS (12033)].— Mathis 1980: 9 –11 [revision].— Mathis and Zatwarnicki 1995: 251 [world catalog].

Diagnosis. This species is distinguished from congeners, especially P. bisetosa , by the following combination of characters: Medium-sized shore flies, body length 3.12–3.65 mm; subshiny dorsally, bluish green to green metallic luster.

Head ( Figs. 27–28 ): Mesofrons greenish blue, shiny; fronto-orbital areas dark brown, microtomentose to subshiny. Face densely microtomentose, grayish tank, dorsum of facial hump slightly darker than face, grayer; paravertical setae shorter than their distance apart; gena-to-eye ratio 0.30; eye ratio 0.64, height-to-length ratio 0.91; eye-width-to-face-length ratio 0.44.

Thorax: Mesonotum ( Fig. 29 ) with anterior area slightly microtomentose, becoming subshiny to shiny posteriorly; acrostichal setulae in 3–4 rows anteriorly, becoming irregular, 5–6 rows posteriorly. Mesopleuron with more subdued coloration than mesonotum, mostly olivaceous gray. Wing nearly transparent to faintly brown.

Abdomen: Concolorous with mesonotum; digitiform lateral process of male tergite 5 elongate, acutely pointed apically; male sternite 5 ( Fig. 34 ) broadly U-shaped with posteriorly extended arms oriented posteriorly, acutely pointed, anterior margin somewhat truncate, posterior margin moderately deeply emarginate. Male terminalia ( Figs. 30–32 ): Surstylus in posterior view with base robustly developed, width 3X apical width, thereafter abruptly narrowed with apical extension narrowly digitiform; medial triangular process less than half length of surstylar arm, not cleft apicomedially; gonite more or less triangular, sider basally, apical half tapered, apex digitiform, apex rounded. Female ventral receptacle as in Fig. 33 with large, mushroom-like operculum.

MAP 5. Distribution map for Paracoenia wirthi Mathis.

Type material. The holotype male is labeled “ USA. CALIF. Inyo Co 1 mi N Tecopa Hot Spg 24 June 1974 [,] Wayne N. Mathis/ HOLOTYPE Paracoenia wirthi Mathis [red; 12033].” Allotype and 21 paratypes (7♂, 14♀; CAS, USNM) bear the same label data as the holotype. Other paratypes as listed in Mathis (1975:78). The holotype male is double mounted (minute nadel), is in excellent condition, and is deposited in the CAS (12033).

Type locality. United States. California. Inyo: Tecopa Hot Springs (1.6 km N; 35°52.7'N, 116°13.9'W); HT ♂, CAS (12033).

Other specimens examined. MEXICO. Baja California: Guadalupe Canyon (32°09.3'N, 115°47.4'W), 19 May 1957, F. X. Williams (1♂, 3♀; CAS). Distrito Federal: Mixquic, Chalco Lake (9 km NW; 19°15.5'N, 98°58.6'W), 1 Aug 1965, K. R. Valley (4♂, 16♀; CAS, USNM).

Distribution (Map 5). Nearctic: United States (California). Neotropical: Mexico (Baja California, Distrito Federal).

Remarks. This species is similar to P. bi s pi no s a but is slightly smaller in body length and less setulose. The ventral margin of the male sternite five is broadly U-shaped, and the connecting bridge is wide; the male tergite five is produced into an acutely pointed process; and the surstylus is more robustly developed basally, and the distal surstylar extensions are narrowly digitiform; the gonite is narrowed toward the apex, and the apex is digitiform, apically rounded.

Figures

FIGURES 27 – 29. Paracoenia wirthi Mathis. (27) head, anterior view; (28) same, lateral view; (29) mesonotum, dorsal view (from Mathis 1980).

FIGURES 30 – 34. Structures of male and female terminalia of Paracoenia wirthi Mathis. (30) epandrium, cerci and surstyli, posterior view; (31) epandrium, cerci, surstyli and gonite, lateral view; (32) ventral apex of male tergite 5, ventral view; (33) female ventral receptacle, lateral view; (34) male sternite 5, ventral view (from Mathis 1980).