Leptomorphus walkeri Curtis

Borkent, Christopher J. & Wheeler, Terry A., 2012, Systematics and Phylogeny of Leptomorphus Curtis (Diptera: Mycetophilidae) 3549, Zootaxa 3549, pp. 1-117 : 68-70

36. Leptomorphus walkeri Curtis

( Figures 41, 76, 89, 123, 140, 150, 154)

Leptomorphus walkeri Curtis, 1831 : plate 365.

Leptomorphus (Leptomorphus) walkeri: Matile, 1977: 144 .

Leia apicalis Roser, 1840: 51 . Synonymized by Landrock, 1917: 39.

References: Grzegorzek 1875: 7 (description of female, wing figure); Mik 1887: 35–6 ( Poland, Austria); Röder 1892: 170 ( Switzerland); Strobl 1897: 15 ( Germany); Kertész 1902: 72 (catalogue); Johannsen 1909:72 (catalogue); Coquillett 1910: 560 (type designations); Landrock 1917: 39 (synonymization of Leia apicalis ), 1940: 39–40 (key, description, wing figure); Edwards 1925: 555–6, 652, Pl. LIX-193 (key, description, biology, wing figure), 1933a: 230 (compared to L. chaseni and L. ornatus ), 1933b: 306 (venation compared to L. fasciculatus ); Brocher 1931: 73–6 (description of larva, egg, and immature behaviour); Enderlein 1936: 13 (key reference); Okada 1936: 100 (compared to L. quadrimaculatus ); Lackschewitz 1937: 13 ( Latvia); Madwar 1937: 52, 54–57, 98–100 (description of larval morphology, biology, numerous figures); Kessel & Kessel 1939: 81 (fungal host record); Séguy 1940: 86–7 (description, biology, figures of egg, larval habitus, and male genitalia); Shaw 1947: 156–157 (comparison to L. nebulosus ); Eberhard 1970: 361,365, 367, 369, 377–8 (compared to L. bifasciatus and L. subcaeruleus ); Plassmann 1971: 62–3 ( Germany, this might be L. forcipatus ); Matile 1977: 141–144 (biology, subgeneric placement); Cole & Chandler 1979: 51 (faunal list); Hutson et al. 1980: 23, 46–47,85, 96 (distribution, description, key, figures of wing and genitalia); Plachter 1980 (immature morphology and behaviour, figures, SEM photos); Santini 1983 (biology), 1985 (biology, figures of all life stages); Krivosheina et al. 1986: 133–4 (key, genitalia figure); Ostroverkhova & Shtakel’berg 1988: 416, 418 (genitalia figure and key reference); Santini & Mazzini 1989 (SEM study of the egg); Zaitzev 1994: 157, 160 (key, re-description, male genitalia figure); Dahl et al. 1995: 17 ( Italy); Yakovlev 1995: 356 (rearing record); Poole and Gentili, 1996: 194 (catalogue); Søli 1997: 6, 9, 10, 14, 32, 34, 46–47 (figure of head, palp, and genitalia, phylogenetic matrix exemplar); Søli et al. 2000: 52 (figure of palp); Kurina 2003: 61 ( Germany); Kurina et al. 2005: 483 ( Sweden); Gammelmo & Søli 2006: 60, 65 ( Norway); Kjaerandsen et al. 2007: 35 (distribution); Papp & Ševčík 2011: 139 (as type species of genus).

DIAGNOSIS: The only extant species of Leptomorphus with the following combination of characters: foretibia with dense row (comb) of short anteroventral bristles ( Fig. 89); wing with dark apical and medial spots present; male genitalia with gonocoxite shorter than tergite 9, sternite 9 not reaching lateral margins of tergite 9 ( Fig. 123).

This species can be distinguished from other Palaearctic species principally based on the bulbous, almost spherical, male genitalia, and the gonocoxites shorter than and placed apically on, tergite 9.

DESCRIPTION: Male. ( Fig. 41) Head: yellow, somewhat dorsoventrally compressed in anterior view. Antenna with basal 3–4 flagellomeres lighter brown, darkening apically; 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 4–5 large bristles, several setae on apicodorsal margin, patch of fine setae apicoventrally; flagellomere 1 with tapered base light brown remainder light brown; flagellomere 6 1.8X as long as broad. Clypeus yellow, strongly protruding, slightly laterally compressed oval; bristles on clypeus yellow, both strong, smaller bristles on entire surface, all directed ventrally, clypeus 2X as long as face. Face yellow; shape a subequal triangle, with fine bristles covering face. Frons yellow; with few bristles medioventrally, frontal furrow running 1/4 distance from dorsal margin towards ventral margin, frontal cleft just anterior of median ocellus. Palpus yellow; segment 1 hidden behind eye, segments increasing in length, segment 5 subequal in length to segment 4 with even width from base to apex, segment 3 without distinct apicolateral patch of fine setae. Labellum yellow. Eye with a number (in ~1/4 of the ommatidial junctions) of long inter-ommatidial setulae scattered on posterior margin. 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 1.5X their own diameter from eye margin, ocellar triangle dark brown/black. Thorax: Length 1.65 ± 0.41 mm (1.19–1.97 mm, n = 10). Mediodorsally brown, remainder yellow. Scutum brown with lighter dorsocentral lines, yellow on anterior corners and posterior and lateral margins, occasionally brown reduced to triangle in center of disc with remainder yellow; surface of scutum covered with small setae; acrostichal setae vaguely present; single dorsocentral seta present anteriorly though remainder could be intermixed with small setae; double row of lateral setae present; patch of setae on scutum at wing base present. Scutellum yellow; with 2–6 large bristles and many small bristles. Prescutum yellow. Mediotergite yellow with 10–20 bristles on posterolateral corners, small bristles covering. 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 straight and clear. Halter yellow. Legs: principally yellow; extreme anteroapical corner yellow on forefemur, on other femora dark brown. Midfemur without apical spine-like process. Tibia with covering of light brown macrotrichia, foretibia with comb of short setae along length of anteroventral surface ( Fig. 89), 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 0.8X length of longest, longest midtibial spur 4.5X apical thickness of midtibia, shortest hind tibial spur 0.8X length of longest, longest hind tibial spur 4X apical thickness of hind tibia. Foreleg first tarsomere 1.7X length of foretibia. Wing ( Fig. 76): Length 7.1 ± 2.2 mm (4.8–8.2 mm, n = 10). Hyaline; apical macula dark brown but fading towards apex and posterior margin, running from anterior to posterior wing margin, beginning halfway along R 5; medial macula extending from R 1 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 clearly reaching wing margin. M 4 -CuA fork arising before origin of r-m. A 2 faintly present as crease. Abdomen: Tergites principally yellow, T1–5 with posterior brown band, T6 with posterior 1/2–3/4 dark brown, T7 dark brown. Tergite 8 smaller than all other abdominal sclerites, without bristles. Genitalia ( Fig. 123): yellow. Sternite 9 sclerotized, more or less circular with apicomedial indentation, 1/2 width and length of T9. Tergite 9 circular with posterior margin concave. Gonocoxite placed apically on T9, medial margins not reaching median line, apex with two short rounded points, bearing gonostylus halfway to apex. Gonostylus swelling from base into a square lobe with medial margin bearing dorsally directed point and bearing several setae, gonocoxite III associated with dorsal margin of gonostylus but not fused to it. Aedeagus 3/4 length of T9, tapering to apex and then swollen at apex with extra sclerotized bumps dorsally, apodemes ~1/4 total length. Parameres strongly sclerotized and complex though main lobe bent and directed dorsally for apical 1/3, apodemes 1/2 length of parameres, strongly united with gonocoxal apodeme.

Female. As for male, except as follows. Thorax: Length 1.71 ± 0.26 mm (1.48–1.89 mm, n = 10). Wing: Length 7.0 ± 1.2 mm (6.2–8.0 mm, n = 10). Legs: Foretibia without comb of short setae on anteroventral surface. Abdomen: Tergite 7 light brown; Cercus yellow.

Immatures. Pupa described by Plachter (1980), Santini (1985). Larva described by Madwar (1937), Plachter (1980), Santini (1985). Egg described by Santini & Mazzini (1989).

BIOLOGY: This species overwinters as eggs that hatch in the early spring. The larvae spin a fine silk sheet under the sporulating surface of various wood inhabiting fungi, which collects the falling spores. The larvae then feed on the spore-covered sheet. Larvae feed on spores of Polyporaceae (Anthrodia radula, Coriolus versicolor , Inonotus hispidus , Poria vaporaria , Schizophora paradoxa , Trametes gibbosa ), Stereaceae ( Stereum ochroleucum ) and Auriculariaceae ( Auricularia mesenterica ) ( Madwar 1937, Santini 1985). This species is also reported as being reared from Discina gigas (Ascomycota: Discinaceae, Yakovlev 1995 ), though this may have been from an individual that had migrated from the host fungus. Pupation occurs underneath or near the host fungus, with the pupa hanging, head down, from a single line attached to the posterior end of their abdomen ( Edwards 1925, Landrock 1940). The final larval skin remains attached to the anchor line behind the pupa ( Madwar 1937). The species is thought to be multivoltine, the number of generations varying depending on the length of the season ( Madwar 1937, Santini 1985). Orthocentrus sp. ( Ichneumonidae : Orthocentrinae ) have been recorded as parasitoids of the immatures ( Séguy 1940). During the autumn females lay light coloured eggs (which gradually darken in colour to brown) on or near the host fungus ( Santini 1985, Santini & Mazzini 1989).

DISTRIBUTION: Europe ( Fig. 140), 35–1400 masl. Previous records of L. walkeri from the Nearctic were due to misidentification of L. hyalinus .

DISCUSSION: 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: Lectotype: Here designated, photographs of the specimen and author’s notebook were examined (available from MVMA): adult female, pinned, labelled “1173a.” corresponding information in notebooks (as given in the original description ( Curtis 1831)): “1173: taken in July on the windows at Arno’s Grove

[type locality], and off a hedge by a wood at Southgate, by my friend Francis Walker, Esq., to whom I have the pleasure of dedicating this fine addition to our fauna.” [ MVMA]

Paralectotype: The Southgate specimen is missing from the Curtis collection at MVMA and Walker collection at BMNH, presumed lost (originally recorded as being ‘in the cabinets of Mr. F. Walker’ ( Curtis 1831).

Other material: AUSTRIA, Langua , 8.viii.1981. (1♀, ZSM) ; Tirol, Igls , 8.vii.1953, J. R. Vockeroth. (2♂, CNC) ; CZECH REPUBLIC, Lanzhot, Ranspurk , 7–9.viii.1991, L. Masner. (1♂, CNC) ; BOHEMIA, Josefuv Dul, Jedlový dul, 1–22.ix.2005, J. Preisler & P. Vonička. (1♂, LEM) ; BOHEMIA, viii.1900. (1♂, MTD) ; FRANCE, 15.xi.1966. (1♂, MNHN) ; 30.x.1966. (1♂, MNHN) ; Centre, Indre-et-Loire, Richelieu , 24.viii.1963. (1♂, MNHN) ; 25.viii.1963. (1♂, MNHN) ; Île-de-France, Seine-et-Marne, Fontainebleau , 14.vii.1992, G. Hodebert. (1♀, MNHN) ; Saint-Augustin , vii.1969, L. Matile. (1♂, MNHN) ; Poitou-Charentes, Deux-Sèvres, Saint-Martin-de- Sanzay , 14 1971, G. Couturier. (1♂, MNHN) ; Provence-Alpes-Côte d'Azur, Bouches-du-Rhône, St-Braume , 1919, A. de Perrin. (1♀, MNHN) ; Hautes-Alpes , Saint-Bonnet-en-Champsaur, vii.1975, C. Girard. (1♀, MNHN) ; Seine et Marne, Bois-le-Roi , 25.viii.1984, P.H. Arnaud, Jr. (1♂, CAS) ; GERMANY, Jungfernhardt, Siebengebirge , 27.ix.1957, E. Schmidt. (1♂, CNC) ; Markgröningen , 21.ix.1970. (1♀, SMNS) ; Baden-Württemberg, 23km NW Freiburg , 26.x.1984, FVA-Abt. Ws Freiburg. (1♀, ZSM) ; Bavaria, Eltmann, Naturpark Steigerwald , 12.viii.1995, A. Floren. (1♂, ZSM) ; Schöngeising , 12.vii.1986. (1♂, ZSM) ; North Rhine-Wesphalia, Cologne , 2.v–15.xi.1995, A.G.W. Topp. (1♂, MTD) ; Saxony, Sächsische Schweiz , (1♀, MTD) ; Württemberg. (1♂, SMNS) ; NORWAY, AK, Nesodden, Skoklefall , 27.vi–9.vii.2005, O. Lønnue. (1♂, LEM) ; SLOVAKIA, Polana Biosphere Reserve , 24.v–11.vii.2007, J. Roháček, J. Ševčík. (1♂, LEM) ; SWITZERLAND, Cheserex , 28.viii.1931, E. Roman. (1♀, MNHN) ; Lugano , vi.1906, W. Schnuse. (1♂, MTD) ; UK, Anderson Co., Northwood , 4.x.1924, E.E. Austen. (1♂, BMNH) ; Hampshire, Minstead , 30.vii.1963, L.W. Siggs. (1♀, BMNH) ; New Forest , 2.x.1901, F.C. Adams. (1♀, BMNH) ; 25.viii.1901. (1♂, MNHN) ; 13.ix.1905. (1♀, MNHN) ; 29.viii.1910, B. Sharp. (1♂, BMNH) ; New Forest, Gorley , 12.viii.1972, Cranston, Dear. (1♂, BMNH) ; Hertfordshire, Hitch Wood , 22.ix.1918, F.W. Edwards. (2♀, BMNH) ; 22.ix.1918. (1♂, CNC) ; ix.1918. (1♀, BMNH) ; Monmouthshire, Monnow Valley , 8.vii.1912, J.H. Wood. (1♂, BMNH) ; Surrey, Old Coulsdon , 19.ix.1934. (1♂, BMNH) .