Boreantrops machinator, Kits, Joel H. & Marshall, Stephen A., 2015

Kits, Joel H. & Marshall, Stephen A., 2015, A revision of Boreantrops Kits & Marshall (Diptera: Sphaeroceridae: Archiborborinae), Zootaxa 3915 (3), pp. 301-355 : 339-341

Boreantrops machinator sp. nov.

(Figs. 19, 86, 87, 88, 125)

Diagnosis. Separable from other members of the emarginatus group by the following characters: Occiput black, prementum reddish brown. Anterior margin of anepisternum shiny below spiracle. Mid tibia without row of anterodorsal bristles. Hind tibia with one ventroapical bristle. Wing with white spots on vein R4+5 basal to r-m crossvein and on vein CuA1.

Description. Occiput black, frons dark brown posteriorly, reddish brown anteriorly, face, gena, prementum, scape, and pedicel reddish brown, first flagellomere orange. Occiput and gena covered with microtomentum, frons with microtomentum on orbital plate extending medially to interfrontal setae and on frontal triangle extending anteriorly to ocellar bristles, with some scattered microtomentum to ptilinal suture, face with microtomentum below lunule and in dense crescent below antenna. Ocellar bristles at level of median ocellus. Subvibrissal and anterior genal bristle about 0.3X length of vibrissa.

Thorax black, mostly covered with microtomentum. Proepisternum shiny, anepisternum mostly shiny with microtomentum covering dorsal quarter and posterior third, katepisternum with a shiny spot behind fore coxa, meron and metapleuron shiny with band of microtomentum between posterior spiracle and hind coxa. Halter white, pale brown below knob.

Legs black, trochanters and joints dark reddish brown, tarsi yellow. Mid tibia with 1 anteroventral, 6 subapical bristles. Hind tibia with 1 long thin anteroventral, 1 ventroapical bristle.

Wing brown, veins dark brown. White spots on crossveins r-m, bm-cu, and dm-cu, vein R4+5 with 1 spot basal to crossvein r-m and 2 distal to crossvein r-m, vein CuA1 with 1 medial spot. Vein R2+3 evenly curved (Fig. 19).

Abdomen with tergites and sternites weakly sclerotized. Syntergite 1+2 with posterolateral corners and a thin band between them strongly sclerotized, tergites 3–4 with a thin posterior band moderately sclerotized.

Male postabdomen: Sternite 5 with lateral margins strongly rounded, posterior margin deeply notched with a sharp point on either side of notch, anterior apodeme longer than external portion, without keel ( Fig. 87 ). Epandrium fused above cerci. Surstylus with anterior thumb-like projection, expanded basally, ventral portion narrow ( Fig. 88 ). Pregonite not fused with postgonite, fairly large. Postgonite very narrow, posterior margin with a rounded projection, lobes not separated, posterior lobe longer. Basiphallus with long, thin epiphallus, preepiphallus very short. Distiphallus with a long dorsal tube with spines near base, flanked by two spike-like sclerites, distal sclerite not projecting dorsally ( Fig. 86 ).

Female unknown.

Type material. Holotype ♂: PERU: Cusco: Wayqecha Biol. Stn., ~ 9 km NE Challabamba , 13°10'S 71°34'W, 2600–2700 m, 1–6 Dec 2011, S.A. Marshall, debu00351213 ( MUSM). Paratype: same data as holotype (1 ♂, DEBU).

Distribution. Only known from the type locality in southern Peru (Fig. 125).

Etymology. The species name is Latin for "a maker of machines" and refers to the wrench-shaped sternite 5; it is a noun in apposition.

Comments. This species appears to be related to B. pollex and B. punctipennis , sharing a basal spot on vein R4+5, a lack of anterodorsal bristles on the mid tibia, and a thumb-like projection on the surstylus. It differs in a number of ways, including lacking wing spots on vein tips and having a spot on vein CuA1 (unique in the genus), anal opening not keyhole-shaped, and having a thicker basiphallus. Despite considerable collecting effort, we did not encounter this species at the type locality in May 2007; perhaps adults are not present at that time of year.

Figures

FIGURES 86 – 92. Boreantrops male terminalia. B. machinator: 86) phallus, postgonite, and phallapodeme, lateral view, 87) sternite 5, 88) right surstylus, interior view; B. pollex: 89) phallus, postgonite, and phallapodeme, lateral view, 90) sternite 5, 91) right surstylus, interior view; B. punctipennis: 92) phallus, postgonite, and phallapodeme, lateral view. sls: spike – like sclerites.