Distictus mexicanus Kasparyan & Ruiz-Cancino 2005
Creators: name: Supeleto, Fernanda A.
name: Santos, Bernardo F.
name: Aguiar, Alexandre P.
Publisher: name: Zenodo
Year: 2019
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Hymenoptera
Ichneumonidae
Distictus
Distictus mexicanus

description: Distictus mexicanus Kasparyan & Ruíz-Cancino, 2005
Figs 11, 16A; Table 1
Distictus mexicanus Kasparyan & Ruíz-Cancino, 2005: 109–111, figs 66–68. Original description, figure. Type ♀ (Universidad Autónoma de Taumalipas, Victoria, Mexico; not examined). Type data: México, Tamaulipas, Victoria, 23 Nov. 1985, E. Ruíz Cancino leg.
Material examined
Total of 22 specimens, 12 ♀♀ and 10 ♂♂.
Paratype
MEXICO • 1 ♀ (pinned; in good condition); Oaxaca, Metate, 85.5 km. SW of Tuxtepec; alt. 900 m; 18 Oct. 1962; H. and M. Townes leg.; USUC {0}.
Other material
COSTA RICA • 1 ♀; Cartago, Braulio Carrillo National Park; alt. 400 m; 10–11 Apr. 1985; H. Goulet leg.; USUC • 1 ♀; Monteverde; 5–6 Feb. 1968; Chas. Palmer leg.; USUC • 2 ♀♀, 2 ♂♂; Escazú; 23 May 1987; H. and M. Townes leg.; USUC • 2 ♀♀; ibid.; 22 and 25 May 1987; USUC • 2 ♂♂; ibid.; 27 May 1987; USUC • 1 ♀; Puntarenas, Monte Verde; alt. ca 1500 m; 4–11 Feb. 1989; D. Grimaldi leg.; lower montane wet forest; AMNH {1}.
GUATEMALA • 1 ♀; Moca, Guatalon; alt. 1000 m; Mar.-Apr. 1931; J. Bequaert leg.; USUC • 1 ♀; Solola, 13.5 km S of Godinez; 31 Dec. 1988; J. la Salle leg.; USUC.
MEXICO • 1 ♀; Veracruz, Orizaba; alt. 1245 m; 27 Jun. 1972; B. Dasch and C. Dasch leg.; USUC • 1 ♀; Veracruz, Rio Metlec, Frotín de las Flores; 16 Jul. 1974; J. Powell leg.; EMEC 731708 {2} • 1 ♂; Chiapas, 3 km NE of San Cristóbal de las Casas; 8 Jun. 1969; B.V. Petersen leg.; USUC • 1 ♂; Chiapas, San Cristóbal de las Casas; alt. 7087 ft; 11 Jun. 1969; B.V. Peterson leg.; CNCI • 4 ♂♂; ibid.; alt. 7200 ft; 24 Jun. 1969; Malaise; CNCI.
Redescription
Female (paratype)
SIZE. Fore wing 10.48 mm long.
HEAD. Clypeus basally moderately convex, at midlength distinctly emarginated, CHW 0.46; median tubercle small, pointed, placed entirely on apical area; apical area narrow. Mandible sparsely pilose, MLW 1.45, MWW 0.55. MSM 0.80. Supra-clypeal area sparsely pilose, almost impunctate. Antenna missing. Supra-antennal area minutely, faintly coriarious, medially with some rugae, ventrally very slightly concave, with distinct median line.
MESOSOMA. Pronotum sparsely pilose, distinctly striate along collar, weakly striate along posterior margin, elsewhere sparsely punctate; epomia moderately stout, distinct and approximately straight only after diverging from pronotal collar, moderately long, ending near dorsal margin of pronotum. Mesoscutum sparsely pilose, densely punctate, mesoscutum 1.12 × as long as wide; notauli medially distinctly convergent, notaulus 0.62 × as long as mesoscutum; scuto-scutellar groove moderately deep, distinctly carinulate. Mesopleuron mostly finely punctate, on dorsal posterior corner distinctly lineate; subalar ridge wide, oval, not keeled; epicnemial carina irregular, almost reaching subalar ridge; sternaulus moderately deep, posterior 0.4 almost indistinct, with distinct vertical wrinkles; sulcus between sternaulus and scrobe distinct; mesopleural fovea represented only by moderately deep pit; mesopleural suture weakly carinulate inside. Metapleuron lineate, moderately pilose; juxtacoxal carina vestigial. Hind coxa moderately punctate.
PROPODEUM. Moderately pilose; anterior margin medially concave; spiracle elongate, SWL 1.67; anterior area coriarious-punctate; posterior area strigate; anterior transverse carina arched slightly forwards, medially more distinctly curved; posterior transverse carina represented by slight, but distinct sublateral crests.
WINGS. Fore wing vein 1M+Rs anteriorly straight, posteriorly curved; crossvein 1cu-a convex, arising a little basad of 1M+Rs; crossvein 1m-cu irregular, distinctly longer than vein 1-Rs+M; limit between veins 1m-cu and 1-Rs+M clearly traceable; vein 1-Rs+M with bulla placed near its midlength; vein 2Cua 1.10 × as long as crossvein 2cu-a; vein 3r-m spectral, distinctly shorter than 2r-m; vein 3-M about as long as 2-M; AWH 1.16, AAW 0.29; areolet 0.40 × as high as wide; APH 1.20; vein 4-M tubular, approximately straight. Hind wing with 8 hamuli; vein M+Cu apically moderately convex; vein M forming distinctly obtuse angle with Cua; HW1C 1.32; vein Cub almost straight, very slightly convex, forming straight angle with Cua; vein 2-Rs apically nebulous.
METASOMA. T1LW 1.19, T1WW 2.84; spiracle not prominent, at 0.49 of T1 length; median depression absent; lateral depression very shallow; dorsolateral carina represented by blunt ridge; ventrolateral carina sharp, complete. T2LW 0.92, T2WW 1.49; thyridium about as wide as long. Tergites 2–8 coriarious; pilosity progressively denser on posterior tergites and dorsally as dense as laterally. Ovipositor straight; OST 0.66; dorsal valve scarcely punctate; ventral valve distinctly overlapping dorsal valve, its apex with 7 teeth.
COLOUR. Head, mesosoma and metasoma black and bright yellow. Head bright yellow; apical 0.6, malar space, supra-antennal area and vertex medially, occiput and posterior 0.5 of gena along its dorsal 0.5 black. Antenna mostly black; scape ventrally with small yellow spot; f6–10 entirely white, f11 partially white; f12–28 ventrally dark brown. Mesosoma black; collar, narrow stripe on dorsal margin of pronotum, propleuron, central spot on mesoscutum, tegula, scutellum, postscutellum, subalar ridge, large central spot on mesopleuron, hypoepimeron, dorsal division of metapleuron, 0.85 of surface of metapleuron and elongate, subtriangular sublateral spots on propodeum bright yellow. All coxae bright yellow, hind one with baso-ventral and apico-dorsal blackish marks; fore and mid first trochanters bright yellow with small basal blackish mark; fore and mid second trochanters dark brown; fore and mid femora yellow with longitudinal dorsal dark brown stripe; all tibiae deep yellow; fore and mid tarsi basally brownish, blackish towards apex. Hind trochanters blackish, femur blackish with ventral face bright yellow; hind t1–4 bright yellow, t5 blackish. Wings hyaline. Metasoma T1 mostly yellow, dorsally with large blackish mark on midlength; T2–8 anteriorly blackish, with posterior and lateral bright yellow stripes, towards posterior segments occupying most of tergite’s surface. S1 mostly blackish; S2–6 bright yellow, except S2–3 laterally with small blackish marks.
VARIATION. Morphometric ranges for this species can be seen in Table 1. Scape sometimes with a small ventral yellow spot; wrinkling/rugae on pronotum sometimes very weak; pilosity at mesoscutum sometimes scarce at anterior lateral lobes, sometimes dense and uniform; specimen from Guatemala generally more pilose; yellow dash on dorsal margin of pronotum from very short, restricted to anterior region, to almost reaching posterior margin of pronotum; yellow mark at hypoepimeron sometimes connected to main mark at mesopleuron; specimen from Costa Rica with head in a brighter tone of yellow. One specimen from Costa Rica (smallest examined) more pilose than all others, with dark marks on legs and metasoma dark brown instead of black, and marks on T1 less extensive.
Male
Similar to female, most important differences as follows. Fore wing 7.5–9.7 mm; sublateral crests on propodeum weak; wrinkling/rugae on pronotum and mesopleuron weak; anterior transverse carina of propodeum medially very weakly arched forwards; crossvein 1cu-a arising distinctly basad of 1M+Rs. Scape dorsally yellow; mesosternum entirely yellow.
VARIATION. Antenna with 29–31 flagellomeres; T1LW 2.80–3.22; T1WW 1.42–2.08. One specimen from Chiapas, Mexico, with crossvein 1cu-a clearly opposite to 1M+Rs; spiracle of T1 sometimes prominent; one specimen from Escazú, Costa Rica, with dark yellow stripes on tergites.
Comments
Structurally, D. mexicanus differs from all other species in the genus by having six exclusive features: mesopleuron mostly finely punctate; supra-clypeal area sparsely pilose and almost impuctate; metapleuron moderately pilose; mesopleural fovea represented only by moderately deep pit; mesoscutum sparsely pilose. Regarding colour, this is the only species in the genus showing a hind femur blackish with ventral face bright yellow (Fig. 11C).
The new species is similar in colour to D. apaensis sp. nov., being the only two species of the genus with posterior and lateral yellow stripes on all tergites (Figs 4C, 11C). Distictus mexicanus can be differentiated from D. apaensis sp. nov. mostly by having the following: body shiny with bright yellow marks (vs matte with pale yellow marks in D. apaensis sp. nov.); hind tibia deep yellow (Fig. 11C) (vs blackish, Fig. 4C); supra-clypeal area entirely yellow (vs with blackish marks); mesoscutum without lateral yellow marks (vs with lateral yellow marks); fore and mid coxae dorsally bright yellow (Fig. 11C) (vs pale yellow with small dorso-apical brown spot, Fig. 4B). Structurally, it differs in 59 features, of which the most important are as follows: metapleuron lineate (Fig. 11B) (vs rugulose); anterior area of propodeum coriarious-punctate (vs coriarious); fore wing vein 3r-m distinctly shorter than 2r-m (vs about as long as 2r-m); vein 3-M about as long as 2-M (vs distinctly longer than 2-M); mesoscutum densely punctate and shiny (vs coriarious, matte); mesopleuron mostly finely punctate, only on dorsal posterior corner distinctly lineate (vs almost entirely lineate); anterior transverse carina slightly arched forwards, medially more distinctly curved (vs laterally approximately straight, medially slightly arched forwards); pronotum distinctly striate along collar, weakly striate along posterior margin (vs weakly striate along posterior margin and collar); scuto-scutellar groove moderately deep and distinctly carinulate (vs shallow, weakly carinulate); AWH 1.04–1.16 (vs 0.94); supra-antennal area medially with some rugae (vs medially coriarious); ventral valve distinctly overlapping dorsal valve (vs slightly overlapping dorsal valve); T1WW 2.43–2.86 (vs 2.19); CHW 0.44–0.48 (vs 0.52); T2WW 1.49–1.67 (vs 1.84).
The new species is also similar in colour to D. daelus sp. nov., from which it can be differentiated by having T4–8 with wide posterior yellow stripes (vs entirely blackish); S2–5 bright yellow (Fig. 11C) (vs brownish with narrow posterior pale yellow stripes, Fig. 10D); hind coxa mostly yellow with large baso-ventral and apico-dorsal blackish marks (Fig. 11C) (vs black with large baso-dorsal yellow spot, Fig. 10D). Structurally, it differs in 49 features, of which the most important are as follows: anterior transverse carina of propodeum slightly arched forwards, medially more distinctly curved (vs distinctly arched forwards, somewhat bell-shaped, Fig. 10E); metapleuron lineate (vs rugulose); mesoscutum and scutellum densely punctate, shiny (vs densely punctate-coriarious, matte); pronotum distinctly striate along collar, weakly striate along posterior margin, elsewhere sparsely punctate (vs weakly striate along posterior margin and part of collar, elsewhere rugulose); APH 0.81–1.20 (vs 1.48); HWIC 1.32–1.83 (vs 2.27); hind coxa moderately punctate (vs punctate-coriarious); MLW 1.45–1.59 (vs 1.19); limit between fore wing crossvein 1m-cu and 1-Rs+M clearly traceable (vs hardly traceable); epicnemial carina irregular (vs distinctly sinuous); sternaulus moderately deep, except posterior 0.4 almost indistinct (vs deeply impressed, posterior 0.25 almost indistinct); mesopleuron mostly finely punctate (vs anteriorly coriarious); OST 0.66 (vs 0.87); mandible sparsely pilose (vs moderately pilose).
The new species is most similar in structure to D. terrosus sp. nov., but differs in 49 features, of which the most important are as follows: limit between 1m-cu and 1-Rs+M clearly traceable (vs 1m-cu continuous with 1-Rs+M); 3r-m distinctly shorter than 2r-m (vs about as long as 2r-m); epomia moderately long, ending near dorsal margin of pronotum (vs short, ending far from dorsal margin of pronotum); tergites 2–8 coriarious (vs coriarious-punctate); mandible sparsely pilose (vs densely pilose); metapleuron moderately pilose (vs densely pilose); median depression of T1 absent (vs very shallow); anterior margin of propodeum medially concave (vs medially very slightly concave).
Distribution records
Mexico, Guatemala, Costa Rica.
description: Published as part of Supeleto, Fernanda A., Santos, Bernardo F. & Aguiar, Alexandre P., 2019, Revision of Distictus Townes, 1966 (Hymenoptera, Ichneumonidae, Cryptinae), with descriptions of ten new species, pp. 1-64 in European Journal of Taxonomy 542 on pages 36-39, DOI: 10.5852/ejt.2019.542, http://zenodo.org/record/3378752