Boreantrops costaricensis, 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 : 316-317

Boreantrops costaricensis sp. nov.

( Figs. 5 , 39, 40 , 107)

Diagnosis. Separable from other members of the avignis subgroup by the following combination of characters: Occiput black. Frons mostly covered with microtomentum. Katepisternum covered with microtomentum. Male sternite 5 with a V-shaped notch in posterior margin.

Description. Head orange, occiput black, area around ocelli may be dark brown. Prementum dark brown on dorsal two-thirds, orange on ventral third. Mostly covered with microtomentum except face, with shiny spots lateral to ocellar triangle, face with a thin band of microtomentum below antenna and lunule. Ocellar bristles lateral to median ocellus. Subvibrissal and anterior genal bristles about 0.3X length of vibrissa.

Thorax black, mostly covered with microtomentum, proepisternum, a spot on anepisternum covering anterior two-thirds and ventral three-quarters, a spot on katepisternum behind fore coxa, and meron and posterior katepisternum shiny ( Fig. 5 ). Halter whitish. Mesoscutum sculptured. Scutellum subtriangular, dorsal surface concave medially.

Legs black, joints paler, trochanters yellow. Fore tarsus with 4 basal tarsomeres ivory white and distal tarsomere pale brown in males, 2 basal tarsomeres ivory white and distal 3 brown in females. Mid and hind tarsi with 2 basal tarsomeres ivory white, distal 3 brown. Mid tibia with one preapical anterodorsal, 4 subapical bristles. Hind tibia with one small ventroapical bristle.

Wing clear, veins yellow to light brown, crossveins whitish.

Abdomen with tergites and sternites weakly sclerotized. Syntergite 1+2 with most of posterior half strongly sclerotized, sclerotized section thinner medially, tergites 3–4 with a thin posterior band moderately sclerotized. Pleural setae on small discs, about the diameter of spiracles.

Male postabdomen: Sternite 5 narrow, slightly wider posteriorly, posterior margin with a V-shaped notch and interrupted row of setae, anterior apodeme about one-half to two-thirds as long as external portion ( Fig. 40 ). Surstylus paddle-shaped. Hypandrial arms with ventral tab-like structures. Pregonite fused with postgonite. Postgonite with lobes narrowly separated, anterior lobe rounded, posterior lobe pointed. Basiphallus with long epiphallus, broad, transparent preepiphallus. Distiphallus with strongly curved, spinose dorsal tube, apex of tube pointed ( Fig. 39 ).

Female postabdomen: Tergites 6–7 and sternites 6–7 moderately sclerotized, tergite 7 with a weakly sclerotized spot medially. Tergites with 3 posterior strips, sternites with 2 posterior strips. Tergite 8 trapezoidal, shallowly emarginated anteriorly, covered with microtomentum except anterior margin. Epiproct without anterior arms, mostly covered with microtomentum except anterior corners, with 2 pairs of setae. Cerci broad. Sclerites of sternite 8 subrectangular, posterior half covered with microtomentum. Hypoproct broad, emarginated anteriorly. Spermathecae barrel-shaped, about 1.5X longer than wide, invaginated apically, sclerotized duct short.

Type material. Holotype ♂: COSTA RICA: Puntarenas: Monteverde Biol. Res., 1500 m, cloud forest, 11–13 Jun 2000, S.A. Marshall, debu00133555 ( INBC). Paratypes: same data as holotype (1 ♂, 1 ♀, DEBU); as above but sweeping, 11 Jun 2000, M. Buck (1 ♀, DEBU); as above but sweeping tree fall & trail, 14 Jun 2000 (2 ♂, 2 ♀, DEBU, INBC); Monteverde, 1500 m, 2–10 May 1988, D. Bell (1 ♀, DEBU); as above but dung traps, 27 Feb 1991, H. & A. Howden (1 ♀, DEBU); Alajuela: Peñas Blancas, 700 m, rainforest, Malaise, 23 May 1987, E. Cruz (1 ♀, ROME); San Ramón Biol. Stn., Arenal Cons. Area, 700 m, yellow pans, 5 Oct 1995, G. Carballo (20 ♂, 22 ♀, DEBU, INBC); Guanacaste: Est. Cacao, Lado SO Vol. Cacao, P.N. Guanacaste, 1000–1400 m, 21–28 May 1992, R. Vargas (1 ♂, INBC); as above but Jun 1990, [no collector] (3 ♀, INBIO ); Est. Cacao, SO de Volcan Cacao, 800–1600 m, 12–17 Jul 1993, M. Rayes (1 ♂, 1 ♀, INBIO ); as above but Jul 1993, J.F. Quesada (1 ♀, INBIO ); as above but Mora, Fonseca, Saborio & Varela (2 ♂, INBIO ); Heredia: Braulio Carrillo Natl. Pk., 1400–1500 m, cool moist river bed, selva premontana s.s., 11 Apr 1985, Goulet & Masner (1 ♀, DEBU); San José: Braulio Carillo Natl. Pk., 9.5km E tunnel, 1000 m, 1 Oct–1 Dec 1989, P. Hanson (1 ♀, INBC); Hwy 2, km 68, around Sphagnum bog/pond, sweeping, 6 Aug 1995, D.C. Caloren (1 ♂, 1 ♀, DEBU).

Distribution. Central to northern Costa Rica (Fig. 107). Elevations from 700–1500 m.

Etymology. The name refers to the occurrence of this species in Costa Rica.

Comments. The sexually dimorphic colouration of the fore tarsi in this species suggest a possible courtship signalling role, perhaps associated with leg waving behaviour similar to that observed in B. albipes (see comments under that species).

Figures

FIGURES 5 – 8. Boreantrops specimens, head and thorax, lateral. 5) B. costaricensis; 6) B. peruvianus; 7) B. emarginatus; 8) B. subemarginatus.

FIGURES 37 – 42. Boreantrops male terminalia. B. avignis: 37) phallus, postgonite, and phallapodeme, lateral view, 38) sternite 5; B. costaricensis: 39) phallus, postgonite, and phallapodeme, lateral view, 40) sternite 5; B. durango: 41) phallus, postgonite, and phallapodeme, lateral view, 42) sternite 5.