Leptomorphus stigmatus Borkent, 2012

Borkent, Christopher J. & Wheeler, Terry A., 2012, Systematics and Phylogeny of Leptomorphus Curtis (Diptera: Mycetophilidae) 3549, Zootaxa 3549, pp. 1-117 : 58-59

29. Leptomorphus stigmatus Borkent , new species

( Figures 34, 71, 81, 115, 134, 150, 153)

DIAGNOSIS: The only extant species of Leptomorphus with the following combination of characters: laterotergite, anepisternum and anepimeron yellow; scutellum yellow; scutum with brown Y-shaped medial marking and prealar brown spots ( Fig. 81);; male genitalia with tergite 9 ending in square lobe (tergal evagination) bearing small medial point, sternite 9 more or less oval shaped ( Fig. 115).

This species can be distinguished from other Afrotropical species by the mostly yellow scutum (brown Yshape and prealar spots, Fig. 81) and abdomen (small posteromedial brown spots on tergites 4, 5), yellow scutellum ( Fig. 34), and lack of small setae covering the scutum (except along dorsocentral lines).

DESCRIPTION: Male. ( Fig. 34) Head: yellow, somewhat dorsoventrally compressed in anterior view. Antenna brown; scape yellow, with brown 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 2–3 large bristles and several setae on apicodorsal margin, a few fine setae on apicoventral margin; flagellomere 1 with tapered base brown remainder brown; flagellomere 6 1.6X as long as broad. Clypeus ivory, dorsoventrally elongate oval; bristles on clypeus light brown, 6–8 strong bristles on ventral margin directed ventrally, remaining setae directed medioventrally, clypeus 1.5X as long as face. Face ivory; shape a subequal triangle, with few bristles ventrolaterally. Frons yellow; with few bristles medioventrally, frontal furrow running full distance from dorsal margin towards ventral margin, frontal cleft initially running to lateral ocellus then barely in front of median ocellus. Palpus yellow; segment 1 small but visible below eye, segments increasing in length, segment 5 2.5X length of segment 4 with central half thinner than base and apex, segment 3 with apicolateral patch of fine yellow setae weakly encircled by strong dark setae. Labellum yellow. Eye with very few, short inter-ommatidial setulae scattered on surface. Occiput yellow with appressed, anteriorly directed setae. Ocelli in a 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 1.8 mm (n = 1). Yellow with dorsal brown spots. Scutum yellow, with spot at wing base and Y-shape originating posteriorly and thickening after split both dark brown ( Fig. 81); surface of scutum bare; acrostichal setae absent; dorsocentral setae present as fine setae for most of length; multiple rows of lateral setae present; patch of setae on scutum at wing base present. Scutellum yellow; with 8 large bristles and few small bristles. Prescutum yellow. Mediotergite yellow with 6–10 bristles on posterolateral corners, anteromedial patch of small bristles. Laterotergite yellow; anterior margin of laterotergite not reaching katepisternum. Anepimeron yellow. Anepisternum yellow. Katepisternum yellow. Antepronotum and proepisternum yellow. Margin of anterior and posterior spiracles yellow with light brown and yellow trichia respectively. Metepisternum yellow. Anapleural suture with anterior portion slightly curved dorsally. Halter yellow. Legs: principally yellow; trochanters with brown margins; extreme anteroapical corner dark brown on all femora; tarsi brown. Midfemur without apical spine-like process. Tibia with covering of brown macrotrichia, foretibia without comb of short setae along length of anteroventral surface, hind tibial spur yellow, remainder brown, foretibial spur length 2X apical thickness of foretibia, midtibia with strong, 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 5X apical thickness of midtibia, shortest hind tibial spur 0.85X length of longest, longest hind tibial spur 4X apical thickness of hind tibia. Foreleg first tarsomere 1.6X length of foretibia. Wing ( Fig. 71): Length 6.2 mm (n = 1). Hyaline; apical macula absent; medial macula absent. Macrotrichia in all cells. Setae on basal posterior margin of wing (along base of cell a) alternating long, short. Calypter with group of macrotrichia. Vein sc-r present, apical end joining R at 2X 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 reaching wing margin. M 4 -CuA fork arising before origin of r-m. A 2 present. Abdomen: Tergites principally yellow, T3–5 with small, posteromedial dark brown spot. Tergite 8 smaller than all other abdominal sclerites, with 2–3 bristles on each apicolateral corner. Genitalia ( Fig. 115): yellow. Sternite 9 sclerotized oval, 1/2 the width of genitalia at widest point, overlapping medial margin of gonoxite. Tergite 9 longer than wide, margins rounded ending in lateral squared off lobe with spine on medial margin and medial U-shaped indentation, one thick and one thin, a ventrally extending thin process at base of posterior lobe forked into two points at apex. Gonocoxite placed basally on T9, medial margin not reaching medial line, bearing gonostylus apically. Gonostylus with two lobes, dorsal lobe a broad based point, ventral lobe half the width of dorsal but 2X length and barely tapering to rounded apex, gonocoxite III fused to dorsolateral margin. Aedeagus equal in length of gonocoxite, tapering towards apex, apodemes 1/4 total length. Parameres a simple taper laterally with a smnall medial bump, apodemes 3/4 length of parameres.

Female. As for male, except as follows. Thorax: Length 1.8 mm. Wing: Length 7.2 mm. Abdomen: Cercus dark yellow.

Immatures. Unknown.

BIOLOGY: Unknown.

DISTRIBUTION: Tanzania ( Fig. 134), 460–1740 masl.

ETYMOLOGY: The species name refers to the dark spots (stigmata) present on the scutum ( Fig. 81).

MATERIAL EXAMINED: Holotype: here designated, adult male, pinned, labelled “ TANZANIA: Tanga region,/ E. Usambara Mts. Amani / Botanical Gardens : 2.xii.1990 / ZMB’s Tanzania Exp. 1990:/ Sweep net, el. 460m.; HOLOTYPE / Leptomorphus stigmatus / Borkent, new species / Det. C.J. Borkent 2012” [ ZMUN].

Paratypes: Labelled as for holotype (1♀, ZMUN) .