Leptomorphus forcipatus Landrock

Borkent, Christopher J. & Wheeler, Terry A., 2012, Systematics and Phylogeny of Leptomorphus Curtis (Diptera: Mycetophilidae) 3549, Zootaxa 3549, pp. 1-117 : 33-35

14. Leptomorphus forcipatus Landrock

( Figures 16, 55, 85, 103, 140, 150, 154)

Leptomorphus walkeri forcipata Landrock, 1918: 107 .

Leptomorphus forcipatus: Séguy, 1940: 86 .

Leptomorphus (Leptomorphus) forcipatus: Matile, 1977: 144 (as synonym of L. quadrimaculatus ).

References: Okada 1936: 100 (synonymized with L. quadrimaculatus ); Séguy 1940: 86 (distribution); Matile 1977: 144 (subgeneric placement), 1988: 234 (catalogue); Ostroverkhova & Shtakel’berg 1988: 416, 418 (genitalia figure and key reference); Zaitzev 1994: 157, 161 (key, re-description, male genitalia figure); Yakovlev 1995: 351, 356 (rearing record); Zaitzev and Ševčík, 2002: 204 (removed from synonymy with L. quadrimaculatus ); Ševčík & Papp 2003: 288 ( Hungary); Gammelmo & Søli 2006: 60, ( Norway); Ševčík 2006: 14 (biology, photo of adults en copula), 2010: 17 (fungal association); Kjaerandsen et al. 2007: 35 (distribution).

DIAGNOSIS: The only extant species of Leptomorphus with the following combination of characters: foretibia with dense row (comb) of short anteroventral bristles; wing with dark apical and medial spots present; male genitalia with gonocoxite smoothly curved along entire length, not swollen at apex and without triangular medial protrusion at base ( Fig. 103).

This species can be distinguished from other Palaearctic species by the long gonocoxites (more than half total length of male genitalia, Fig. 103), almost completely dark yellow abdomen (tergite 7 and posterior half of tergite 6, brown, Fig. 16) and scutum evenly covered with small setae. It is the only species with long gonocoxites that has the gonocoxite both smoothly curved (not strongly bent as in L. talyshensis , Fig. 121) and without a triangular protrusion mediobasally ( Fig. 103).

DESCRIPTION: Male. ( Fig. 16) Head: brown dorsally yellow ventrally, somewhat dorsoventrally compressed in anterior view. Antenna brown; scape yellow, with light 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 light brown/yellow, with 3 large bristles, several setae on apicodorsal margin, a few fine setae on apicoventral margin; flagellomere 1 with tapered base brown remainder brown; flagellomere 6 2.0X as long as broad. Clypeus light brown, strongly protruding, slightly laterally compressed oval; bristles on clypeus light brown, both strong, smaller bristles on entire surface, all directed ventrally, clypeus 2X as long as face. Face brown; shape a slightly wider than tall triangle, with fine bristles covering face. Frons brown; with few bristles medioventrally, frontal furrow running 3/4–full 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 1.5X length of segment 4 with even width from base to apex, segment 3 with apicolateral patch of fine yellow setae encircled by strong dark setae. Labellum yellow. Eye with long interommatidial setulae in ~1/4 of the ommatidial junctions, scattered on all but medial margin. Occiput brown with appressed, anteriorly directed setae. Ocelli with median slightly in front of laterals, space between ocelli less than diameter of laterals, lateral ocelli 1.5X their own diameter from eye margin, ocellar triangle dark brown. Thorax: Length 1.54 mm (1.39–1.64 mm, n = 3). Dorsally brown, laterally yellow. Scutum brown on disc with lighter dorsocentral lines, yellow on anterior corners, lateral and posterior margins except for dark spot at wing base; surface of scutum covered with small setae; acrostichal setae absent; dorsocentral setae probably present but not clearly distinguishable from other setae; multiple rows of lateral setae present; patch of setae on scutum at wing base small. Scutellum yellow to light brown; with 6–8 large bristles and many small bristles. Prescutum brown. Mediotergite yellow, darker posteriorly with 8–16 bristles on posterolateral corners, small bristles covering. Laterotergite yellow; anterior margin of laterotergite abutting katepisternum. Anepimeron yellow. Anepisternum yellow. Katepisternum yellow with anteroventral corner brown. Antepronotum and proepisternum light brown to yellow. Margin of anterior and posterior spiracles yellow with yellow trichia. Metepisternum yellow. Anapleural suture straight and clear. Halter stem yellow, knob light brown. Legs: principally yellow; extreme anteroapical corner dark brown on all femora; foretarsi brown. Midfemur without apical spine-like process. Tibia with covering of brown macrotrichia, foretibia with weak comb of short setae along length of anteroventral surface ( Fig. 85), tibial spurs yellow, 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 0.7X length of longest, longest midtibial spur 4.5X apical thickness of midtibia, shortest hind tibial spur subequal to length of longest, longest hind tibial spur 4.5X apical thickness of hind tibia. Foreleg first tarsomere 1.7X length of foretibia. Wing ( Fig. 55): Length 7.2 mm (6.6–7.5 mm, n = 3). Hyaline; apical macula not reaching wing tip, extending faintly along posterior wing margin into apex of cell cua 1 and cup though not joining with medial macula; medial macula extending from Sc to stem of M 1+2. Macrotrichia in all cells. Setae on basal posterior margin of wing (along base of cell a) all the same length. 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 thinning towards wing margin. M 4 -CuA fork arising well before origin of r-m. A 2 faintly present as crease. Abdomen: Tergites T1–6 yellow, T6 brown posteriorly, T7 brown. Tergite 8 smaller than all other abdominal sclerites, without bristles. Genitalia ( Fig. 103): light yellow. Sternite 9 lightly sclerotized, posteriorly directed triangle 1/2 length of T9 but as wide as genitalia. Tergite 9 subcircular though apical margin somewhat flattened. Gonocoxite placed centrally on T9, much longer than length of T9, medial margin not reaching median line, bearing gonostylus basally. Gonostylus a single lobe tapering to a point apically, strongly bent at halfway point and with several setae, gonocoxite III associated with dorsal margin of gonostylus but not fused to it. Aedeagus 3/4 length of T9, tapering slightly towards apex for basal 3/4 and then strongly indented and remainder squarish, apodemes ~1/2 total length. Parameres consisting of two lobes, lateral lobe a broad based spine curving laterally, medial lobe 2X length of lateral and very thin, apodemes 1/2 length of parameres, strongly united with gonocoxal apodemes and with a dorsal pointing small hook.

Female. No specimens examined, but coloration apparently similar to male with female terminalia yellow ( Zaitzev & Ševčík 2002).

Immatures: Undescribed.

BIOLOGY: Larvae are known to feed on the spores of Stereum ( S. subtomentosum and S. hirsutum ; Zaitzev & Ševčík 2002) and Trichaptum ( Yakovlev 1995, Jakovlev 2011). Adults copulate soon after emergence from the pupa, and copulation lasts several hours ( Ševčík 2006).

DISTRIBUTION: Finland, Czech Republic, Slovakia, Sweden, Norway, Hungary, Germany and Switzerland ( Fig. 140), 35–780 masl.

DISCUSSION: This species was originally described as a subspecies of L. walkeri , and was later thought to be a junior synonym of L. quadrimaculatus ( Okada 1936, Matile 1988). Zaitzev & Ševčík (2002) considered it significantly different from the latter, reinstated it and designated a lectotype from the single type specimen they found. Lectotype information from Zaitzev & Ševčík (2002): adult male, pinned, labelled “Árvaváralja, Kertész, 24.vi.1914, [underside of label] Collectio K. Landrock, K Czižek, D. Jacentkovský” [type depository: MMBC].

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 Leptomorphus and placed solely in the genus Leptomorphus .

MATERIAL EXAMINED: CZECH REPUBLIC, Bohemia, Josefuv Dul, Jedlový dul, 1–22.ix.2005, J. Preisler & P. Vonička. (1♂, LEM); GERMANY, Saxony, Sachsische Schweiz N.P., 22–23.vi.1989, U. Kallweit. (1♂, MTD); NORWAY, AK, As; Arungen, Syverud, 15.viii–3.ix.2003, E. Rindal, L. Aarvik. (1♂, ZMUN); SLOVAKIA, Polana Biosphere Reserve , 24.v–11.vii.2007, J. Roháček, J. Ševčík. (1♂, LEM) .