Leptomorphus grjebinei Matile

Borkent, Christopher J. & Wheeler, Terry A., 2012, Systematics and Phylogeny of Leptomorphus Curtis (Diptera: Mycetophilidae) 3549, Zootaxa 3549, pp. 1-117 : 38-39

17. Leptomorphus grjebinei Matile

( Figures 19, 58, 105, 134, 150, 153)

Leptomorphus (Austroleptomorphus) grjebinei Matile, 1977: 154 .

References: Crosskey 1980: 1221 (catalogue appendix); Matile 1997: 149 (key).

DIAGNOSIS: The only extant species of Leptomorphus with the following combination of characters: a thick medial yellow line on the otherwise brown scutum; foretibia with dense row (comb) of short anteroventral bristles; missing wing vein sc-r, male genitalia with gonostylus only a single lobe, apical tergal evaginations present ( Fig. 105). This is also the only species known from Madagascar.

This species can be distinguished from other Afrotropical species by the presence of small setae on the entire surface of the scutum (not just restricted to dorsocentral lines and lateral margins).

DESCRIPTION: Male. ( Fig. 19) 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 absent; pedicel yellow, with 1 large bristle, few setae on apicodorsal margin, none ventrally; flagellomere 1 with tapered base light brown remainder light brown; flagellomere 6 1.4X as long as broad. Clypeus yellow, square; bristles on clypeus brown, 4–6 strong bristles on ventral margin directed ventrally, a number of bristles on remainder (almost in rows) all directed medioventrally, clypeus 1.1X as long as face. Face yellow; shape a just longer than wide triangle, bare. Frons yellow; with 3–4 bristles medially, frontal furrow running 1/2 distance from dorsal margin towards ventral margin, frontal cleft running to lateral ocellus. Palpus with segments 1–2 yellow, 3–5 light brown; segment 1 hidden behind eye, segments 2–4 subequal, segment 5 1.5X 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 inter-ommatidial setulae absent. Occiput yellow with appressed, anteriorly directed setae. Ocelli with median slightly in front of laterals, space between ocelli less than diameter of laterals, lateral ocelli 3X their own diameter from eye margin, ocellar triangle dark brown/black. Thorax: Length 1.23 mm (n = 1). Brown dorsally, yellow laterally. Scutum anterior margin and inverted medial triangle yellow/white as well as posterior corners and central lateral spot, two dark brown spots posterolaterally only reaching lateral margin at wing base; surface of scutum covered with small setae; acrostichal setae absent; single dorsocentral seta present anteriorly; single row of lateral setae present; patch of setae on scutum at wing base small. Scutellum yellow; with 2 large bristles and many small bristles. Prescutum yellow. Mediotergite brown with medial line lighter with 6–12 bristles on posterolateral corners. Laterotergite yellow; anterior margin of laterotergite not reaching katepisternum. Anepimeron yellow. Anepisternum yellow. Katepisternum yellow with small brown spot anterodorsally. Antepronotum and proepisternum yellow. Margin of anterior and posterior spiracles yellow with light brown and yellow trichia respectively. Metepisternum white. Anapleural suture straight but faint. Halter stem brown, knob white. Legs: principally yellow; extreme anteroapical corner yellow on forefemur, on other femora dark brown; hind tibia light brown. Midfemur without apical spine-like process. Tibia with covering of brown macrotrichia, foretibia with remnant of comb of short setae along length of anteroventral surface, tibial spurs brown, foretibial spur length 2X apical thickness of foretibia, midtibia with strong, dorsal, bare patch of even thickness for 2/3 of its length, placed centrally, shortest midtibial spur subequal to length of longest, longest midtibial spur 4X apical thickness of midtibia, shortest hind tibial spur subequal to length of longest, longest hind tibial spur 3.5X apical thickness of hind tibia. Foreleg first tarsomere 1.7X length of foretibia. Wing ( Fig. 58): Length 5.2 mm (n = 1). Hyaline; apical macula absent; medial macula absent. 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 absent. 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 after apex of r-m. A 2 absent. Abdomen: Tergites 1 brown, T2–6 brown with lateral yellow spots, T7 with anterior 1/2 brown remainder yellow. Tergite 8 smaller than all other abdominal sclerites, with 3–4 bristles on each apicolateral corner. Genitalia ( Fig. 105): yellow. Sternite 9 not clearly visible possibly due to condition of specimen. Tergite 9 as wide as long, widening apically into lateral process bearing two points and medial square-shaped indentaiton. Gonocoxite placed basally on T9, medial margin reaching medial line, bearing gonostylus apically. Gonostylus a single broad-based lobe tapering to a point apically, gonocoxite III fused to dorsolateral margin. Aedeagus 4/5 length of gonocoxite, tapering towards apex (slight central swelling), apodemes 1/3 total length. Parameres a simple taper, apodemes ~4/5 length of parameres.

Female. As for male, except as follows. Thorax: Length 1.19 mm (1.15–1.23 mm, n = 2). Wing: Length 5.0 mm (4.6–5.5mm, n = 2). Abdomen: Sternites white/yellow. Cercus yellow.

Immatures. Unknown.

BIOLOGY: Unknown.

DISTRIBUTION: Eastern rainforests of Madagascar ( Fig. 134), 1000–1100 masl.

DISCUSSION: The female specimen from near Ranomafana has less dark brown on its thorax and tergites than the other specimens. As discussed below in the phylogeny section, the placement of Leptomorphus species in subgenera ( Matile 1977) is not supported by our phylogenetic results. This species is therefore removed from the subgenus Austroleptomorphus and placed solely in Leptomorphus .

MATERIAL EXAMINED: Holotype: adult male, pinned on double mount minuten, genitalia in glass vial on pin, labelled “[ MADAGASCAR] Madagascar Nord / Montagne d’Ambre [Ambohitra] 1000m / det Diego-Suarez/ 23.XI–4.XII.[19]57, B. Stuckenberg; [Red label] HOLOTYPE; Leptomorphus / ( Austroleptomorphus )/ grjebinei n. sp. ♂ ht/ L. Matile det. 1974” [ MNHN].

Paratypes: Same data as holotype (1♀, labelled as Allotype, MNHN) .

Other material: MADAGASCAR, Prov. Fianarantsoa, 7km W Ranomafana , 1100m, 1–7.XI.1988, W.E. Steiner (1♀, USNM) .