Meggoleus hidalgoensis Khalaim & Ruiz-Cancino, 2020

Khalaim, Andrey I. & Ruiz-Cancino, Enrique, 2020, Contribution to the taxonomy of Mexican Tersilochinae (Hymenoptera, Ichneumonidae), with descriptions of five new species, ZooKeys 974, pp. 1-21 : 1

Meggoleus hidalgoensis Khalaim & Ruiz-Cancino sp. nov. Figures 1-8

Differential diagnosis.

The new species differs from other species of Meggoleus by the combination of its relatively small, not enlarged propodeal spiracles (Figs 5 , 6 ) and black antenna (Fig. 3 ).

Description.

Female. Body length 4.4 mm. Fore wing length 3.4 mm.

Head, in dorsal view, strongly constricted, almost straight (holotype) or rounded posterior to eyes; gena 0.65-0.75 × as long as eye width. Eyes glabrous. Clypeus relatively large, lenticular, ca. 2.6 × as broad as long (Fig. 4 ), weakly convex in lateral view, separated from face by sharp furrow; smooth, with scattered punctures in upper part, sometimes slightly scabrous near upper and lower margins. Mandible not constricted, with upper and lower margins mostly subparallel, distinctly widened at level of teeth; teeth somewhat divergent, upper tooth ca. 1.5 × longer than the lower. Malar space 0.9-1.2 × as long as basal mandibular width. Antennal flagellum (Fig. 3 ) with 15 or 16 flagellomeres, basally very slender; basal flagellomeres more than 2.5 × as long as broad, subapical flagellomeres distinctly elongate; flagellomeres 4-7 bearing long and thin subapical finger-shaped structures on outer surface (hardly discernible in light microscope). Face weakly convex. Face, frons, and vertex subpolished, weakly shining, with very fine, mostly indistinct punctures. Gena polished, with fine and sparse punctures. Occipital carina complete, somewhat dipped mediodorsally, evenly arcuate in dorsal view. Hypostomal carina absent at least in lower part.

Mesoscutum very finely and shallowly granulate, sometimes almost smooth on lateral lobes, impunctate or with very fine inconspicuous punctures, weakly shining to dull. Notaulus impressed, with distinct wrinkle on anterolateral side of mesoscutum (Fig. 3 ). Scutellum with lateral longitudinal carinae at basal 0.3-0.5. Epicnemial carina not reaching front margin of mesopleuron, continuing above along front margin of mesopleuron towards subtegular ridge, and vanishing there (Fig. 6 ). Foveate groove long, narrow, sharp, anteriorly upcurved, with distinct transverse wrinkles (Figs 3 , 6 ). Mesopleuron smooth, very finely punctate (sometimes punctures indistinct), with impunctate area centrally. Propodeal spiracle round, not enlarged, separated from pleural carina by 1.0-2.0 × diameter of spiracle (Figs 3 , 5 ). Propodeum with narrow median longitudinal furrow which is 0.7-1.1 × as long as apical area (Fig. 5 ). Dorsolateral area polished, impunctate (Figs 5 , 6 ). Apical area flat, rounded or pointed anteriorly (Fig. 5 ); apical longitudinal carinae usually complete and reaching transverse carina anteriorly, sometimes partly obliterated.

Fore wing with second recurrent vein (2m-cu) postfurcal, weakly pigmented in anterior part and distinct posteriorly. First abscissa of radius (Rs+2r) straight, somewhat longer than width of pterostigma. First and second abscissae of radius (Rs+2r and Rs) meeting at slightly acute angle. Intercubitus (2rs-m) slightly thickened, approximately as long as abscissa of cubitus between intercubitus and second recurrent vein (abscissa of M between 2rs-m and 2m-cu). Metacarpus (R1) almost reaching apex of fore wing. Second abscissa of postnervulus (Cu&2cu-a) present, thus brachial cell is closed posteriorly. Hind wing with nervellus (cu1&cu-a) weakly reclivous. Legs slender. Tarsal claws long and slender, not pectinate.

First tergite ca. 3.8 × as long as posteriorly broad, smooth, sometimes with very weak striae laterally just before glymma; petiole more or less trapeziform in cross-section centrally; in dorsal view, postpetiole distinctly widened at base, wider than petiole and clearly separated from it (Fig. 7 ); in lateral view, upper margin of tergite weakly arcuate in basal 0.6 and somewhat stronger arcuate in apical 0.4 (Fig. 6 ). Glymma distinct, situated in apical 0.6 of tergite, joining by weak groove with lower part of postpetiole (Fig. 6 ), but sometimes this groove is vestigial and glymma is virtually isolated. Second tergite ca. 1.85 × as long as anteriorly broad (Fig. 7 ). Thyridial depression shallow to deep, 2.0-3.0 × as long as broad, with posterior end rounded. Ovipositor weakly and nearly evenly bent upwards over its total length, with weak dorsal subapical depression (Fig. 8 ); sheath 1.0-1.4 × as long as first tergite (1.4 × in holotype).

Head and mesosoma black. Palpi, mandible (teeth dark red), lower 0.4-0.5 of clypeus and tegula brownish yellow. Scape and pedicel of antenna yellow-brown ventrally and brown dorsally; flagellum brownish black, sometimes pale at base. Pterostigma brown. Legs brownish yellow; hind coxa darkened with brown at base; apex of hind tibia and hind tarsus infuscate. First tergite brown to dark brown. Metasoma posterior to first tergite brown or dark brown dorsally to brownish yellow ventrally.

Male. Similar to female; flagellum slender, more or less tapered towards apex, with 16 flagellomeres (Fig. 2 ).

Variation.

Pale specimens have head and mesosoma mostly reddish brown rather than black, and metasoma pale brown to yellow. Two females from the State of Oaxaca possess foveate groove of mesopleuron very thin, represented by a line of sharp and deep pits.

Etymology.

The species is named after the type locality, [State of] Hidalgo.

Material examined.

Holotype female (UNAM), Mexico, Hidalgo, Huasca de Ocampo, Rancho Santa Elena, 20°06'N, 98°31'W, 2330-2535 m, Hueyapan River, 25.I-23.II.2006, coll. A. Contreras R. et al.

Paratypes. Mexico: 1 female (UAT, apices of antennae absent), Tamaulipas, Gómez Farías, La Gloria, 11.III.1995, coll. D. Zuñiga. 1 female (UAT, head absent), 1 male (UNAM), Hidalgo, same data as holotype, but 29.XI-26.XII.2005. 1 female, 1 male (ZISP), Morelos, N of Tepoztlán, path to El Tepozteco, 1800-2000 m, 11.X.2014, coll. A.I. Khalaim. 1 female (TAMU), Veracruz, 7 mi. W of Jalapa [Xalapa], 24-25.III.1974, coll. J.C. Schaffner. 1 female (TAMU), Oaxaca, 10.8 mi. (= 17.4 km) S of El Punto, 6100 ft (= 1860 m), 19.VII.1987, coll. R. Wharton. 1 female (TAMU), Oaxaca, 15 mi. (= 24 km) NE of Ixtlán de Juárez, Llano de las Flores, 21.VII.1985, coll. J.B. Woolley & G. Zolnerovich.

Distribution.

Mexico (Tamaulipas, Hidalgo, Morelos, Veracruz, Oaxaca).

Figures

Figures 1 - 8. Meggoleus hidalgoensis sp. nov., holotype female (all except 2) and paratype male (2) 1, 2 habitus, lateral view 3 head with antennae and mesosoma, lateral view 4 head, front view 5 propodeum dorso-postero-lateral view 6 posterior part of mesosoma and base of metasoma, lateral view 7 postpetiole and second tergite, dorsal view 8 apex of metasoma with ovipositor, lateral view.