Robustagramma pallidistylum Cui and Marshall, 2005

Marshall, Stephen A. & Cui, Yongsheng, 2005, Systematics of Robustagramma, a new genus of New World Sphaeroceridae (Diptera), Zootaxa 1026 (1), pp. 1-122 : 103-105

Robustagramma pallidistylum Cui and Marshall , new species

( Figs. 324–330 )

As described for Robustagramma flavistylum except as follows.

Body length 1.7–2.3 mm. Interfrontal bristles in three (sometimes four) pairs, upper pair small. Middle interfrontal bristle often slightly reclinate but lower interfrontal bristle slightly declinate. Face of male with central ridge between antennae similar in width to, or slightly wider than, width of scape. Eye height ca. 1.8–1.9 times genal height. Aristal hairs nearly 3 times as long as basal width of arista. Maximum palpal width ca. 1/5–1/4 as long as palpus. Preapical palpal bristle 1.5–2.0 times as long as maximum width of palpus.

Two pairs of postsutural dorsocentral bristles, anterior pair slightly longer than middle prescutellar acrostichal bristles. Presutural dorsocentral setulae slightly longer than acros­ tichal setulae. Acrostichal setulae in 6 rows between anterior dorsocentral bristles. Posterodorsal katepisternal bristle over two thirds as long as distance between bristle base and wing base; sometimes an additional, very small, setula in front of anterodorsal katepisternal bristle. Length of second costal sector ca. 0.55–0.57X length of third. Discal cell with a short stump vein CuA 1, 1–3 vein widths. Mid femur with 2–3 anterior subapical bristles. Mid femur of male with 2 rows of 12 ventral proximal bristles and a row of anteroventral bristles on basal half.

Male terminalia: Dorsomedial length of epandrium ca. 0.25X length of sternite 8. Surstylus mostly setose, but setae distinctly short. Cercus similar in length to surstylus, distal half very narrow. Apex of postgonite truncate. Distiphallus long.

Female terminalia: Tergite 10 and cerci conspicuously long. Sternite 8 reduced to 2 small sclerites. Spermatheca wrinkled distally.

Holotype (♂, DEBU) and paratypes (6 ♂, 6 ♀, DEBU): MEXICO: Oaxaca. 8 km S Suchix Tepec , 10.viii.1986, H.&A. Howden.

Other paratypes: MEXICO: Oaxaca. 25 mi S Valle Nacional, 6400', Cloud Forest , dung, 23–30.vii.1971 (6 ♂, 1 ♀, DEBU) ; 12 mi S Valle Nacional, 3200', Trop. Montane Forest , carrion (shrimp), 22–31.vii.1971 (1 ♂, 1 ♀, DEBU) ; 5 mi S Valle Nacional , 1600', tropical oak evergreen, dung, 20.vii–1.viii.1971 (1 ♀, DEBU) ; 4.2 mi E Jct. Mex 175 & Yuvila Rd. , 7900' (2 ♂, 2 ♀, DEBU) , 7600' (1 ♂, DEBU) , oak pine, dung, 9–19.viii.1973; 14.2 mi S Ixtlan de Juarez, 7600', Oak woodland, dung, 10–18.viii.1973 (1 ♂, 1 ♀, DEBU) ; 6.6 mi N Ixtlan de Juarez, 8300', Oak woodland, human dung, 10–18.viii.1973 (1 ♀, DEBU) , A. Newton. Puebla. 3 mi S Xicotepec de Juarez , 4000', cloud tropical evergreen forest, human dung, 3–8.vii.1971 (1 ♂, DEBU) ; 5 mi W Huanchinango , 6000', hardwoods and pine, human dung, 3–7.vii.1971 (2 ♂, 1 ♀, DEBU) ; 4.5 mi E Teziutlan , 5000', cloud forest, human dung, 10–14.vii.1971 (2 ♂, 1 ♀, DEBU) , A. Newton. Hidalgo. 3.2 mi N Tlanchinol , 5100', cloud forest, dung, 6–11.vii.1973 (9 ♂, 5 ♀, DEBU) ; same data as previous label except for : 3.5 mi N Tlanchinol , human dung (6 ♂, 3 ♀, DEBU) ; same data as previous label except for : 2.5 mi N Tlanchinol , 5200', dung (5 ♂, 4 ♀, DEBU) , A. Newton. Veracruz. 10 mi SW Teocelo , 4400', oak, wet human dung 11–16.vii.1971 (11 ♂, 2 ♀, DEBU) ; 4 mi N Huatusco , 4100', cloud forest, dung, 11–16.vii.1971 (1 ♂, 4 ♀, DEBU) , A. Newton. Veracruz. 7 km E Huatusco , 1250m, cloud forest, FIT, 22.vi–2.viii.1983, S.&A. Peck (1 ♂, 1 ♀, DEBU) . San Luis Potosi. 14 mi W Xilitla , 4800', Liquidambar forest, dung, 20– 28.vi.1971, A. Newton (8 ♂, DEBU) .

Etymology: The specific epithet describes the pale surstylus of this species.

Comments: Robustagramma pallidistylum is closely related to Robustagramma flavistylum , but can be distinguished from the latter by its smaller eyes (the eye height is about 1.8–1.9 times of the genal height), its pale yellow surstylus with distinctly short setae, and the long tergite 10 and cercus of the female.

Figures

FIGURES 324–330. Robustagramma pallidistylum sp. nov.: 324, posterior view of male terminalia; 325, lateral view of male terminalia; 326, lateral view of male internal genitalia; 327, male sternite5;328,dorsalviewoffemaleterminalia;329,ventralviewoffemaleterminalia;330,spermathecae.