Notiocoenia acutella 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 : 16-17

2. Notiocoenia acutella Mathis

Figs. 9–11 , Map 2

Notiocoenia acutella Mathis 1980: 14 .— Mathis and Zatwarnicki 1995: 249 –250 [world catalog].

Diagnosis. Although very similar to specimens of P. paniculata , specimens of this species may be distinguished by the following character states of the male preabdomen and terminalia: 4th abdominal sternite subrectangular, posterior margin truncate, setae at posterior margin slightly larger but not clumped; ventral margin of epandrium with conspicuous U-shaped medial emargination in posterior view; aedeagus more slender and with more distinct taper toward apex; gonite with acutely pointed process posteriorly. As in description of N. paniculata except as follows: Moderately small to medium-sized shore flies, body length 2.78–3.93 mm.

Head: Gena-to-eye ratio 0.16–0.18; eye height-to-width ratio 0.86–0.89.

Thorax: Legs tending to consistently be more yellowish orange, with little or no blackish coloration.

Abdomen: Male sternite 4 subrectangular, posterior margin truncate, setae at posterior margin slightly larger but not clumped or clustered. Male terminalia ( Figs. 9–11 ): Epandrium in posterior view ( Fig. 9 ) as an inverted U, more thinly developed dorsally, in lateral view ( Fig. 10 ) conspicuously thinner dorsally, thereafter ventrally gradually becoming wider, widest at ventral 1/3, ventral 1/3 tapered to a rather bluntly rounded point; ventral margin, which is probably the fused surstylus, truncate with a conspicuous U-shaped medial emargination (best seen in posterior view); cerci free in cercal cavity, not fused with epandrium, semihemispherical; aedeagus in lateral view ( Fig. 11 ) elongate, slender, narrowly tubular, very gradually tapered to apical point; gonite well developed, with acutely pointed process posteriorly.

Type material. The holotype male is labeled “ CHILE: Osorno Prov. [Termas de] Aguas Calientes (1 km SE) 530 m. elev. 7–8 Feb. 1978 WNMathis/ HOLOTYPE Notiocoenia acutella Mathis [handwritten, red].” The holotype is double mounted (minute nadel), is in good condition, and is deposited in the USNM (76067). The allotype female and 10 paratypes (6♂, 4♀; DEI) are labeled “Sud. Chile [Aisen] 14. 4. 40. (14 Apr 1940) Puerto Puyuguapi [44°18'S, 72°32'W] leg. G. H. Schwabe 201.” Other paratypes are as follows: CHILE: Coquimbo: El Pangue (30°26'S, 71°01'W), 1 Nov 1954, P. G. Kuschel (1♂; USNM). Malleco: Perquenco (16.1 km N; 38°25'S, 72°23'W), 1 Jun 1951, A. E. Michelbacher, E. S. Ross (1♂; CAS). Osorno: Anticura (1 km W; 40°39'S, 72°10'W; 430 m), 1–3 Feb 1978, W. N. Mathis (1♂; USNM).

Type locality. Chile. Osorno: Termas de Aguas Calientes (1 km SE; 40°41'S, 72°21'W; 530 m). Distribution (Map 2). Neotropical: Chile (Coquimbo, Malleco, Osorno ), between 38°–44°S.

MAP 2. Distribution map for Notiocoenia acutella Mathis.

Figures

FIGURES 9 – 11. Structures of male terminalia of Notiocoenia acutella Mathis. (9) epandrium and cerci, posterior view; (10) same, lateral view; (11) internal structures of male terminalia, lateral view (from Mathis 1980).