Robustagramma crassipalpus 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 : 46-48

Robustagramma crassipalpus Cui and Marshall , new species

( Figs. 99–106 )

Body length 1.5–2.0 mm. General color yellow to brownish yellow, lightly pollinose.

Head: Face, antenna and frons brownish yellow; gena yellow. Interfrontal bristles in 4 pairs, uppermost pair very small. Two orbital bristles, anterior orbital bristle slightly longer than half of posterior. Uppermost orbital setula present between orbital bristles; lower orbital setulae smaller. Inner and outer occipital bristles similar in length. Postvertical bristles cruciate, slightly smaller than inner occipitals; postocellar bristles weak or absent. Eye height ca. 3 times genal height. Arista slightly longer than head height. Aristal hair long, ca. 3 times basal width of arista. Two palpal bristles different in length, preapical bristle distinctly longer than submedial one, but not longer than maximum palpal width.

Thorax: Prosternum with 3 or 4 pairs of setulae. Dorsocentral bristles in 2 postsutural pairs, anterior pair short, similar in length to middle prescutellar acrostichal bristles. Acrostichal setulae in 8 rows between anterior dorsocentral bristles. Apical scutellar bristles 1.8 times length of scutellum. Posterodorsal katepisternal bristle half as long as distance between bristle base and wing base; anterodorsal katepisternal bristle small. Halter knob pale to brownish; stem pale. Wing clear, almost without pigmentation. Costa between humeral and subcostal break similar in thickness to second costal sector. Length of second costal sector ca. 0.54–0.58X length of third. R 2+3 almost straight, ca. 1.8 times as long as first sector of R 4+5. Costa ending before wing apex, extending past R 4+5 by less than one vein width. Discal cell without appendices. Tarsi and fore tibiae yellow, legs otherwise brownish yellow. Mid tibia with a single dorsal proximal bristle, single distal anterodorsal, dorsal, and posterodorsal bristles, 2–3 dorsal setulae near middle, and a strong anterodorsal setula just basal to anterodorsal distal bristle; mid tibia without an anterodorsal bristle near middle. Mid femur with 5 or 6 anterior bristles on distal half, and a posterodorsal apical bristle. Mid tibia of male with an apicoventral and several short ventral bristles on distal half; also corresponding femur with 7–9 ventral proximal bristles.

Male abdomen: All abdominal tergites uniformly brownish, similar in length. Sternite 5 nearly twice as long as sternite 4, with a dark, bare, prominent posteromedial margin. Dorsomedial length of epandrium ca. 0.5X length of sternite 8. Surstylus mostly setose. Cercus shorter than surstylus, with three pairs of small bristles at base only. Postgonite with a concave apex. Distiphallus long, with many tiny spicules on inner surface of dorsal sclerites. Ejaculatory apodeme small.

Female abdomen: Tergite 1–7 unifromly pigmented and entire. Sternite 7 similar in length to sternite 6, rounded posteromedially. Sternite 8 entire, anterolateral margins articulated with two sclerites of tergite 8. Sternite 10 large, densely setulose. Spermathecae short, cylindrical, wrinkly, with long ducts, ca. 3 times as long as spermatheca.

Holotype (♂, DEBU): BELIZE: San Ignacio. Maya Mtn. Lodge, malaise, forest edge, 19.i.1991, S. A. Marshall.

Paratypes: COSTA RICA: Heredia, La Selva , 50–100m, carrion trap, 18.ii.1980, H. F. Howden (1 ♀, DEBU) . MEXICO: Tabasco, 46 mi SE Villahermosa , km 74, 150ft, 8– 15.viii.1971, secondary vegetation rainforest, human dung, A. Newton (1 ♀, DEBU) . PANAMA: Canal Zone, Barro Colorado Island , 9.i.1929, C. H. Curran (1 ♂, DEBU) .

Etymology: The specific epithet refers to the conspicuously thickened palpus of Robustagramma crassipalpus

Figures

FIGURES 99–106. Robustagramma crassipalpus sp. nov.: 99, dorsal view of left mid tibia of male;100, posterior view of male terminalia; 101, lateral view of male terminalia; 102, lateral view of male internal genitalia; 103, male sternite 5; 104, dorsal view of female terminalia; 105, ventral view of female terminalia; 106, spermathecae.