Leptomorphus brandiae Borkent, 2012

Borkent, Christopher J. & Wheeler, Terry A., 2012, Systematics and Phylogeny of Leptomorphus Curtis (Diptera: Mycetophilidae) 3549, Zootaxa 3549, pp. 1-117 : 20-21

5. Leptomorphus brandiae Borkent , new species

( Figures 6, 46, 82, 95, 127, 143, 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 genitalia with tergite 9 rounded basally, tapering to a single, long, point posteriorly that extends beyond cerci, gonocoxite without gonocoxal lobe ( Fig. 95).

This species can be distinguished from other Neotropical species without R 4 by the distinctive pointed tergite 9 of the large male genitalia ( Fig. 95). It also has the darkest legs of any of the species (e.g. hind femur 2/3 dark, Fig. 6).

DESCRIPTION: Male. ( Fig. 6) Head: light brown-brown, somewhat dorsoventrally compressed in anterior view. Antenna dark 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 1 large bristle, several setae on apicodorsal margin, patch of fine setae apicoventrally; flagellomere 1 with tapered base yellow, remainder dark brown; flagellomere 6 1.1X as long as broad. Clypeus light brown, slightly laterally compressed oval; bristles on clypeus brown, 6–8 strong bristles on ventral margin directed ventrally, remaining setae directed medioventrally, clypeus 2X as long as face. Face light brown; shape a slightly wider than tall triangle, with few bristles ventrolaterally. Frons brown; bare, frontal furrow running 1/10–1/4 distance from dorsal margin towards ventral margin, frontal cleft just anterior of median ocellus. Palpus with segments 1–4 yellow, segment 5 white ( Fig. 82); segment 1 small but visible below eye, segments increasing in length, segment 5 2X length and 1.5X width of segment 4 with even width from base to apex and covered in fine white setulae, segment 3 with very small lateral patch of fine setae encircled by dark setae. Labellum light brown. Eye with very few, short inter-ommatidial setulae scattered on surface. Occiput brown 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 1.31 mm (n = 1). Dark brown with yellow lateral spots. Scutum dark brown/black with blue-green specks, pair of small yellow anterolateral spots; surface of scutum covered with trichia; acrostichal setae absent; single dorsocentral seta present anteriorly; two thirds row of lateral setae present; patch of setae on scutum at wing base small. Scutellum dark brown with covering of fine trichia; bristles absent. Prescutum yellow. Mediotergite dark brown with 6 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 dark brown. Katepisternum brown with dorsal third yellow. Antepronotum and proepisternum brown. Margin of anterior and posterior spiracles yellow with yellow trichia. Metepisternum brown. Anapleural suture with anterior portion slightly curved dorsally. Halter with basal 1/3 of stem ivory, apical portion and knob dark brown. Legs: principally dark brown; coxae white except apical margin; fore- and midfemur with apical 1/3–1/2 yellow, hind femur with yellow on third quarter; extreme anteroapical corner brown on forefemur, on other femora dark brown; fore- and midtibia with basal 1/2 yellow. Midfemur without apical spine-like process. Tibia with covering of brown macrotrichia, foretibia with comb of short setae along length of anteroventral surface, hind tibial spur dark brown, remainder brown, foretibial spur length 2X apical thickness of foretibia, midtibia with strong, dorsal, bare patch of even thickness for 3/5 of its length, placed basally, shortest midtibial spur 0.84X length of longest, longest midtibial spur 4X apical thickness of midtibia, shortest hind tibial spur subequal to length of longest, longest hind tibial spur 3.75X apical thickness of hind tibia. Foreleg first tarsomere 1.8X length of foretibia. Wing ( Fig. 46): Length 5.25 mm. Hyaline; apical macula dark brown but fading apically, running from anterior to posterior wing margin, beginning halfway along R 5; 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 and sparse in basal cells. 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 slightly concave for entire length. M 1 reaching apex before R 5, apices of M veins thinning towards wing margin. M 4 -CuA fork arising at the same level as r-m. A 2 absent. Abdomen: Tergites and sternites principally dark brown, T3–5 with anterolateral yellow spots. Tergite 8 smaller than all other abdominal sclerites, without bristles. Genitalia ( Fig. 95): basal half brown remainder light yellow/white. Sternite 9 very small, sclerotized, posteriorly directed Y-shape, not reaching to gonocoxal margin. Tergite 9 longer than wide, rounded basally, tapering to a single, long point posteriorly that extends beyond cerci. Gonocoxite placed 1/4 way toward apex of T9, medial margin not reaching medial line, bearing gonostylus on apical 1/3. Gonostylus a single broad-based lobe tapering to a point apically with small setae basally, gonocoxite III fused to dorsolateral margin. Aedeagus equal in length to gonocoxite, tapering to middle and then slightly bulbous apically, apodemes 1/3 total length. Parameres a slightly curved taper, 1.2X length of apodemes, apodemes strongly united with gonocoxal apodemes.

Female. As for male, except as follows. Thorax: Length 1.56 mm (n = 1). Wing: Length 6.15 mm (n = 1). Legs: Foretibia without comb of short setae on anteroventral surface. Abdomen: Cercus yellow.

Immatures. White/ivory background colour with small, dark, spots covering the dorsal and lateral surfaces. Follows the general habitus for other known species ( Fig. 127).

BIOLOGY: Larvae and pupae were collected from an encrusting fungus on the underside of wet discarded lumber near La Fortuna, Costa Rica. Larvae had spun sheets and were feeding on the spores that accumulated, as described for other species ( Fig. 127). The pupae were suspended from their head and tail.

DISTRIBUTION: Costa Rica ( Fig. 143), 300–560 masl.

ETYMOLOGY: This species is named for my wife Brandi Borkent, as it is a particularly beautiful species, and in thanks for her support and encouragement in all matters relating to life during my doctoral program as well as for her help while I was collecting the paratype specimens.

MATERIAL EXAMINED: Holotype: here designated, adult male, pinned with genitalia in plastic vial on pin, labelled “ COSTA RICA: Prov. Limon. R.B./ Hitoy Cerere , Send. Espavel. 560m. / (9.66°N, 83.03°W) 14–25.iii.2003./ E. Rojas, B. Gamboa, W. Arana / Tp. Interseccion, sample #73474; HOLOTYPE ♂ / Leptomorphus brandiae /Borkent, new species / Det. C.J. Borkent 2012” [ LEM].

Paratypes: COSTA RICA: Alajeula , 4.3km SSE La Fortuna, 15.viii.2010, C.J. Borkent [with cast off pupal skin] (2♂, 1♀, LEM) .