Boreantrops apterus, 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 : 313-314

Boreantrops apterus sp. nov.

( Figs. 30, 35, 36 , 105)

Diagnosis. This is the only member of the genus with reduced wings.

Description. Head orange, occiput brown to blackish medially, maxillary palp yellow. Occiput and gena covered with microtomentum, frons mostly covered with microtomentum, with shiny spots lateral to ocellar triangle and interfrontal plates shiny medially to interfrontal setae, face mostly shiny with a broad band of microtomentum below antenna and lunule. Ocellar bristles at or just anterior to level of anterior margin of median ocellus. Specimens from Costa Rica occasionally missing ocellar bristles, one pair of orbital bristles, or outer vertical bristles, specimens from Panama with only one pair of orbital bristles. Subvibrissal and anterior genal bristles about 0.3X length of vibrissa.

Thorax black, postalar callus reddish. Mostly covered with microtomentum, proepisternum shiny, anepisternum with an anteroventral shiny spot covering anterior three-fifths and ventral two-thirds, katepisternum with a shiny spot behind fore coxa, metapleuron with a shiny spot ventral to posterior spiracle. Presutural and anterior postsutural dorsocentral bristles about 0.5X length of posterior dorsocentral bristle. Mesoscutum smooth. Halter reduced to a tiny white nub. Wing reduced to a small brown flap ( Fig. 30).

Legs black, trochanters reddish brown, joints and tarsi orange. Mid tibia with anterodorsal row, 1 anteroventral, 1 posteroventral, and 6 subapical bristles. Hind tibia with anteroventral bristle at three-quarters, 2 ventroapical bristles.

Abdomen with syntergite 1+2 completely heavily sclerotized, black, covered with microtomentum, tergite 3 mostly heavily sclerotized, tergite 4 with a median heavily sclerotized spot in female and a thin heavily sclerotized bar in male, tergite 5 not sclerotized in female, weakly sclerotized with anterior corners heavily sclerotized in male. Sternites weakly sclerotized in both sexes.

Male postabdomen: Sternite 5 narrow anteriorly, strongly flared posteriorly, posterior margin with a shallow notch and interrupted row of setae, anterior apodeme about as long as external portion ( Fig. 36 ). Surstylus paddleshaped. Hypandrial arms with ventral tab-like structures. Pregonite narrow, discrete. Postgonite with lobes narrowly separated, anterior lobe rounded, posterior lobe long, pointed. Basiphallus with long epiphallus, broad, transparent preepiphallus. Distiphallus with curved, spinose dorsal tube, distal portion of tube long, flattened ( Fig. 35 ).

Female postabdomen: Tergite 6 not sclerotized, tergite 7 with anterior and lateral margins sclerotized. Sternite 6 with anterior margin only sclerotized, sternite 7 mostly sclerotized, unsclerotized patch medially. Tergites with 3 posterior strips, sternites with 2 posterior strips. Tergite 8 trapezoidal, covered with microtomentum except anterior corners. Epiproct with microtomentum medially, one pair of setae. Cerci broad. Sclerites of sternite 8 broad, posterior third with microtomentum. Hypoproct subrectangular. Spermathecae very long, twisted, annulated, without invaginations, sclerotized duct about as long as bulb.

Type material. Holotype ♂: PANAMA: Chiriquí: Cerro Punta, 5 km ESE, 2600 m, dung traps, 23–28 May 1977, S. Peck, debu00276324. Paratypes: same data as holotype (20 ♂, 28 ♀, DEBU); as above but carrion traps (10 ♂, 9 ♀, DEBU). COSTA RICA: San José: San José, 74 km SE, dung trap, 25 Feb 1984, H.F. Howden (3 ♂, 8 ♀, DEBU).

Distribution. Known from the Cordillera de Talamanca of Costa Rica and Panama (Fig. 106).

Etymology. The name refers to the lack of developed wings, and is a declinable adjective.

Figures

FIGURES 31 – 36. Boreantrops male terminalia. B. albipes: 31) phallus, postgonite, and phallapodeme, lateral view, 32) sternite 5; B. alytothrix: 33) phallus, postgonite, and phallapodeme, lateral view, 34) sternite 5; B. apterus: 35) phallus, postgonite, and phallapodeme, lateral view, 36) sternite 5. bp: basiphallus, dp: distiphallus, dt: dorsal tube; ep: epiphallus, keel: transparent keel on dorsal tube; pa: phallapodeme, pep: preepiphallus, prg: pregonite, ptg: postgonite.