Sclerocoelus caligarius, Kuwahara & Marshall & Paiero, 2025

Kuwahara, Gregory K., Marshall, Stephen A. & Paiero, Steven M., 2025, A revision of the genus Sclerocoelus Marshall (Diptera: Sphaeroceridae), European Journal of Taxonomy 979, pp. 1-277 : 34-36

Sclerocoelus caligarius sp. nov.

urn:lsid:zoobank.org:act:C0843A0E-3398-4A24-8087-390CA037D5B4

Figs 5H, 29–31

Etymology

This name refers to the boot-shaped male surstylus (from the Latin ‘ caligarius ’, meaning ‘of/for a soldier’s boot’).

Material examined

Holotype

BOLIVIA • ♂; La Paz , Caranavi, 23 km NE of Caranavi; 14 Apr. 2001; S.A. Marshall leg.; roadside/ stream sweep; CBFC debu00165694.

Paratypes

BOLIVIA – La Paz • 2 ♂♂, 2 ♀♀; same data as for holotype; CBFC • 3 ♂♂, 1 ♀; same data as for holotype; DEBU .

Description

BODY ( Fig. 29A). Length 2.9–3.9 mm. Head dark brown, almost black; lunule reddish. Frontal width 2.3× frontal height. Three pairs of strong interfrontal bristles surmounting a fine fourth pair; anterior orbital 0.5–0.6 × length of posterior. Palpus pale brown. Eye large, greatest height about 3.0× shortest genal height. Thorax dark brown, scutum with reddish lateral edges. Two pairs of dorsocentral bristles (anterior pair only slightly larger than surrounding acrostichal setulae) separated by 9–10 rows of acrostichal setulae. Membrane around prosternum with 2–3 small, setulae-bearing sclerites. Legs brown, foreleg paler. Fore femur with three large but unusually fine ventral preapical setae. Ventral surface of male mid tibia with two rows of stout setae along apical half. Wing ( Fig. 5H) hyaline. CS2 0.9 × CS3. Halter brown.

MALE ABDOMEN ( Figs 29B–C, 30). Dark brown, posterior edges of tergites sometimes slightly desclerotized.T2–5and S2–4 uniformly long-setose with large posterolateral setae. S5broad, 1.0 ×length of S4, anteromedially desclerotized, long setae largely restricted to lateral margins, posteromedially with a darkened lobe bearing 4 setulae and flanked by on either side by 6–7 setae. Anterior flange of S6+7 not developed. Sclerite A pale, fused to S6+7, densely setulose; sclerites B and C apparently absent; sclerite D small, dark, triangular, situated under and to the left of sclerite E; sclerite E larger, triangular with an elongate anterolateral apodeme on right side; sclerites F and G fused, large, with a flattened apodeme extending to left side and a triangular ventral lobe articulating with apodeme of sclerite E; ring sclerite indistinct. Epandrium large, 0.8 × length of S8, height 1.4 × maximum length and 0.7 × maximum width, densely long-setose; perianal pads well developed, triangular, dark with stout spicules, apices fused. Pseudocercus small, connected to epandrium by a thin sclerotized strip, bearing 3 setae; halves of subepandrial sclerite strongly arched, medially fused. Subcercus large, main part triangular and curved inwards with a broad, desclerotized margin along ventral margin; main part with a broad, transverse part articulating with ventrolateral corner of epandrium and other subcercus laying perpendicular to main part. Hypandrium with very large, broad, apically flattened anteromedial apodeme. Surstylus large, yellow, boot-shaped, with a small anteroventral lobe resembling heel of a shoe, margins densely setose but outer surface largely bare and shiny. Postgonite elongate, sinuate with a slight constriction in basal fifth and tapered in apical half. Phallapodeme very large, dark with a large dorsal ‘fin’, apex flattened; basiphallus stout, slightly curved; distiphallus largely membranous with an M-shaped dorsolateral sclerite (a small dorsal sclerite connected to longer, sinuate lateral sclerites) and a broad ventral sclerite.

FEMALE ABDOMEN ( Fig. 31). T7 broad, simple; T8 divided into a broad, pale, dorsal sclerite and two large, dark, lateral sclerites, posterolateral corners greatly expanded to a narrow point. Epiproct large, subrectangular, anteromedially desclerotized, posteromedially emarginate, and entirely setulose. Cercus elongate, apically pointed with stout apical and dorsal setae. S7 broad, subtriangular, broadly desclerotized posteriorly with four large posterior setae; S8 desclerotized, U-shaped, laterally darker. Hypoproct with thickened anteromedial setulae. Three spermathecae, bulb stout, bean-shaped, finely striate with shallow invaginations basally and subapically, both with a small, finger-like, central process.

Distribution

Neotropical: Bolivia.

Remarks

Sclerocoelus caligarius sp. nov. is externally similar to the other members of the S. galapagensis group, which possess small sclerites in the membrane around the prosternum. This species can be easily separated from others in the species group by the dark brown head with limited orange on the frons, the posteromedial projection of the male S5, and the long posterolateral projections on the female T8. The holotype and many of the paratypes were collected by sweeping over a roadside ditch and stream at the same locality in the Bolivian Yungas Region as half a dozen congeners ( S. andensis , S. binus sp. nov., S. brasilensis , S. bucki sp. nov., S. copiosus sp. nov., and S. xynos sp. nov.). All of these species except for S. bucki and S. xynos belong to the S. galapagensis group.