Leptomorphus crassipilus Borkent, 2012

Borkent, Christopher J. & Wheeler, Terry A., 2012, Systematics and Phylogeny of Leptomorphus Curtis (Diptera: Mycetophilidae) 3549, Zootaxa 3549, pp. 1-117 : 25-27

9. Leptomorphus crassipilus Borkent , new species

( Figures 10, 50, 98, 142, 150, 155)

DIAGNOSIS: The only extant species of Leptomorphus with the following combination of characters: scutum and scutellum evenly covered with fine trichia; male foretibia with a dense row (comb) of short anteroventral bristles; palp segment 5 with thick covering of fine, white, setulae; male tergite 9 posterior margin rounded laterally and concave medially, lateral process apex with 5 rows of tightly spaced short blunt brown bristles; gonocoxite placed basally on, and subequal in length to, tergite 9, gonostylus ~2/3 length of gonocoxite with two apical processes, medial one most pronounced and tapering to a point, the lateral ½ the length of medial, thin and rod-like ( Fig. 98).

This species is distinguished from most other Neotropical species missing R 4 by the yellow or white scutellum and striped abdomen ( Fig. 10). It can be distinguished from L. eberhardi by the rows of short spines on the posterior margin of tergite 9 ( Fig. 98).

DESCRIPTION: Male. ( Fig. 10) Head: yellow, circular in anterior view. Antenna brown; scape yellow, with yellow setae in single apical row extending from dorsum laterally into thick patch covering apicoventral process, basal third and entire medial surface bare, anterobasal patch of setulae present; pedicel yellow, with 2 large bristles, few setae on apicodorsal margin, patch of fine setae apicoventrally; flagellomere 1 with tapered base yellow remainder brown; flagellomere 6 1.9X as long as broad. Clypeus light brown, slightly laterally compressed oval; bristles on clypeus yellow, 6 strong bristles on ventral margin directed ventrally, remaining setae directed medioventrally, clypeus 2X as long as face. Face light brown; shape a subequal triangle, bare. Frons light brown; with many bristles covering ventral half, frontal furrow running 1/10 distance from dorsal margin towards ventral margin, frontal cleft just anterior of median ocellus. Palpus yellow; segment 1 small but visible below eye, segments increasing in length, segment 5 not visible, segment 3 without definite patch of fine setae. Labellum brown. Eye with very few, short inter-ommatidial setulae scattered on surface. Occiput yellow with appressed, anteriorly directed setae. Three ocelli; straight line, space between ocelli less than diameter of laterals, lateral ocelli 2X their own diameter from eye margin, ocellar triangle dark brown/black. Thorax: Length 1.19 mm (n = 1). Dark brown with yellow lateral spots. Scutum dark brown/black with blue-green specks, pair of small yellow posterolateral spots; surface of scutum covered with trichia; acrostichal setae absent; single dorsocentral seta present anteriorly; single row of lateral setae present; patch of setae on scutum at wing base present. Scutellum yellow; without large bristles but with covering of fine trichia. Prescutum yellow. Mediotergite brown with 4 bristles on posterolateral corners, and covering of appressed trichia. Laterotergite brown, with covering of appressed trichia; anterior margin of laterotergite abutting katepisternum. Anepimeron brown with posterodorsal corner yellow. Anepisternum brown. Katepisternum brown with dorsal third yellow. Antepronotum and proepisternum yellow. Margin of anterior and posterior spiracles yellow with yellow trichia. Metepisternum yellow. Anapleural suture with anterior portion slightly curved dorsally. Halter with basal 1/3 of stem ivory, apical portion and knob dark brown. Legs: principally yellow; trochanters light brown; hind femur with basal and apical 1/4 brown; extreme anteroapical corner yellow on forefemur, on other femora dark brown; tarsi brown. Midfemur without apical spine-like process. Tibia with covering of brown macrotrichia, foretibia with comb of short setae along length of anteroventral surface, though bristles further apart than in other species, tibial spurs dark brown, foretibial spur length 1.9X apical thickness of foretibia, midtibia with faint, dorsal, bare patch of even thickness for 3/4 of its length, placed basally, shortest midtibial spur 0.8X length of longest, longest midtibial spur 5.3X apical thickness of midtibia, shortest hind tibial spur 0.8X length of longest, longest hind tibial spur 3.5X apical thickness of hind tibia. Foreleg first tarsomere 1.6X length of foretibia. Wing ( Fig. 50): Length 6.0 mm (n = 1). Hyaline; apical macula dark brown running from anterior to posterior wing margin, beginning halfway along R 5, but fading towards apex and posterior margin; medial macula extending from Sc to posterior wing margin (fainter on posterior third). Macrotrichia in all cells, though absent from posterobasal margin of cell a. Setae on basal posterior margin of wing (along base of cell a) alternating long, short. Calypter with a few short setae. Vein sc-r present, apical end joining R within its own length prior to origin of Rs. R 4 absent. R 5 straight, slight posterior turn near tip. M 1 reaching apex just before R 5, apices of M veins clearly reaching wing margin. M 4 -CuA fork arising apically of origin of r-m. A 2 absent. Abdomen: Tergites principally dark brown, T3–6 with anterior 1/3–1/2 yellow. Tergite 8 smaller than all other abdominal sclerites, with 3–4 bristles on each apicolateral corner. Genitalia ( Fig. 98): brown. Sternite 9 not clearly visible due to condition of specimen. Tergite 9 as wide as long, margins ~parallel, ending apically in broad rounded lobes and shallow medial indentation, rounded lobe bearing 5–6 rows of short, blunt, closely spaced bristles on ventroapical surface. Gonocoxite placed basally on T9, medial margin almost reaching medial line, bearing gonostylus on apical 1/3. Gonostylus with two lobes, basolateral lobe shortest and thin, apicomedial lobe broad based and 2X length of basal but tapering to point, bearing setae along medial margin, gonocoxite III fused to dorsolateral margin. Aedeagus 3/4 length of gonostylus, tapering towards apex (slight central swelling), apodemes not observable in specimen. Parameres strongly hooked at apex with apical margin serrated, apodemes 2/5 length of parameres.

Female. Unknown.

Immatures. Unknown.

BIOLOGY: Unknown.

DISTRIBUTION: Northern Argentina ( Fig. 142), 980 masl.

ETYMOLOGY: The species name refers to the rows of thick (crassi-) setae (-pilus) on the apex of tergite 9, which is a unique characteristic within Leptomorphus .

MATERIAL EXAMINED: Holotype: here designated, adult male, pinned, labelled “ Argentina / Tucuman / S. Javier [26.783°S, 65.383°W]/ Col. Duret / [vertically on margin] IV 44; [pink label with genitalia in between two coverslips attached]; 20779; HOLOTYPE ♂ / Leptomorphus crassipilus / Borkent, new species / Det. C.J. Borkent 2012” [ MNHN]