Spathius mexicanus Belokobylskij & Zaldívar-Riverón

Female. Body length 3.8–5.2 mm; fore wing length 2.4–3.2 mm. Head. Head width (dorsal view) 1.5–1.6 times its median length, 1.3–1.4 times width of mesoscutum. Vertex convex. Head behind eyes (dorsal view) distinctly and evenly roundness decreased; transversal diameter of eye (dorsal view) 1.4–1.7 times longer than temple. Ocelli with ocellar triangle base 1.15–1.25 times its sides; POL 1.0–1.3 times Od, 0.35–0.4 times OOL. Eye glabrous, its maximum diameter 1.3–1.4 times minimum diameter. Malar space 0.4–0.45 times maximum diameter of eye, 0.75–0.85 times basal width of mandible. Face slightly convex, its width equal to maximum diameter of eye, 1.1 times height of face and clypeus combined. Clypeal suture distinct and complete. Ventral margin of clypeus with distinct flange. Hypoclypeal depression medium-sized and rounded, its width 0.9 times the shortest distance from edge to eye, 0.4–0.45 times width of face. Occipital carina dorsally complete, not broken toward ocellar triangle, not reaching hypostomal carina and obliterated on short distance before area posterior to the mandible base. Hypostomal flange rather wide. Antennae slender, almost filiform, 28–36-segmented, 1.2–1.3 times longer than body. Scape 1.6–1.7 times longer than maximum width. First flagellar segment 4.7–5.2 times longer than apical width, 1.1–1.2 times longer than second segment. Penultimate segment 3.2–3.5 times longer than width, 0.55–0.6 times as long as first segment, 0.9–1.0 times as long as apical segment; the latter subpointed or truncate apically and without spine. Mesosoma. Mesosoma not depressed, maximum length 1.9–2.0 times its maximum height. Pronotal keel indistinct or fine, without posterior branch. Pronotum (dorsal view) subanteriorly with distinct transverse carina. Pronotal lateral depression shallow, delineated by carinae above and below, wide, almost entirely smooth. Mesoscutum (lateral view) slightly curvedly and highly elevated above pronotum, its median lobe (dorsal view) distinctly convex anteriorly and without anterolateral corners; mesoscutum in dorsal view 1.0–1.1 times as long as wide. Notauli complete, wide, deep anteriorly, becoming shallow posteriorly, coarsely crenulate and sometimes with fine granulation. Scutellar sulcus (prescutellar depression) deep, rather short, with three coarse carinae, finely rugulose, 0.25–0.3 times as long as scutellum. Scutellum slightly convex, with distinct lateral carinae. Subalar depression narrow, very shallow, widely and coarsely striate. Precoxal sulcus (sternaulus) about 0.5 times length of lower part of mesopleuron, slightly curved, wide, deep, distinctly and densely crenulate. Postpectal carina absent. Metanotum with short, wide and rounded apically dorsal tubercle. Metapleural flange (lobe) narrow, long, subpointed or weakly rounded apically. Propodeum without lateral tubercles. Wings. Fore wing 4.0–4.1 times longer than wide. Pterostigma 4.5–5.0 times longer than its maximum width. Radial vein (r) arising behind middle of pterostigma, from its basal 0.6. Radial (marginal) cell not shortened, metacarp (R1) 1.2–1.3 times longer than pterostigma. Second radial abscissa (3RSa) 3.1–3.4 times longer than first abscissa (R) and forming with it very obtuse angle, almost as long as the weakly curved third abscissa (3RSb), almost as long as first radiomedial vein (2RS). Second radiomedial (submarginal) cell not or slightly narrowed distally, its length 3.6–3.9 times maximum width, 1.6–1.8 times length of brachial (first subdiscal) cell. Second abscissa of medial vein ((RS+M)b) rather long, 0.4–0.5 times as long as recurrent vein (m-cu). Nervulus (cu-a) postfurcal, distance between basal vein and nervulus 0.5–0.6 times nervulus length. Parallel vein (2CUb) not interstitial, arising from anterior quarter or third of distal margin of brachial (first subdiscal) cell. Mediocubital vein (M+CU) in distal half weakly curved to longitudinal anal vein (1-1A). Hind wing 5.1–5.5 times longer than its maximum width. First costal abscissa (C+Sc+R) 0.6–0.7 times as long as second abscissa (Sc+R). First abscissa of mediocubital vein (M+CU) 0.6–0.8 times as long as second abscissa (1M). Recurrent vein (m-cu) more or less distinctly sclerotised, pigmented, distinctly antefurcal, strongly oblique towards base of wing. Legs. Fore tibia anterior margin with long, dense spines arranged in narrow stripe. Segments of middle tarsus considerably longer than their width. Hind coxa with distinct basoventral tubercle, 1.8–2.0 times longer than maximum width. Hind femur elongate-oval, 3.2–3.5 times longer than wide. Hind tibia with outer apical lobe and two-three slender and long spines. Hind tarsus 0.9–1.0 times as long as hind tibia. Hind basitarsus 0.55–0.6 times as long as remaining segments combined. Second segment of hind tarsus 0.5–0.55 times as long as basitarsus, almost as long as thickened fifth segment (without pretarsus). Tarsal segments slightly thickened. Claws short, thick basally, with short curved apical part. Metasoma. Petiole (lateral view) ventrally almost straight, dorsal basal half slightly arched and apical half nearly straight, highest in basal third or fourth; petiole slender in dorsal view, slightly widening at spiracular tubercles and distinctly apically. Length of petiole 2.9–3.1 times its apical width, 2.2–2.4 times length of propodeum; apical width about 2.0 times width at spiracle level, 2.6–2.7 times minimum subbasal width. Second tergite without laterotergites separated. Suture between second and third tergites (second suture) absent. Median length of second and third tergites combined 1.0–1.1 times its basal width, 0.6–0.65 times their maximum width. Ovipositor straight. Ovipositor sheath 2.5–2.9 times longer than petiole, 1.1–1.5 times longer than metasoma, 2.0–2.3 times longer than mesosoma, as long as or slightly longer than fore wing. Sculpture and pubescence. Vertex entirely smooth. Frons densely and slightly curvedly transverse striate, with fine rugulosity between striae, sometimes almost smooth anteriorly or medioposteriorly. Face distinctly striate-rugose, smooth on median vertical area and laterally. Temple entirely smooth. Mesoscutum distinctly and densely granulate, granulation usually situated in fine semicircular subtransverse aciculation, coriaceous to almost smooth posteriorly, its medioposterior third with several distinct longitudinal striae, median lobe with dense and fine or very fine additional transverse striation; lateral lobes near notauli with distinct or coarse additional rugosity. Scutellum entirely or almost entirely smooth. Mesopleuron medially smooth, longitudinally striate in upper 0.3–0.5. Metapleuron entirely coarsely rugose-reticulate. Propodeum in anterior (dorsal or basolateral) areas almost smooth or sometimes finely reticulate, with more or less coarse additional carina along areola margins; basal (median) carina short or almost absent; areola narrow and long, 3.0–4.0 times longer than wide; petiolate area long and rather narrow, separated from areola by distinct carina; propodeum mainly coarsely transverse striate. Hind coxa entirely or almost entirely coarsely transverse striate, finely sculptured below. Hind femur entirely smooth. Petiole dorsally distinctly and more or less sparsely longitudinally striate and with distinct dense rugulosity between striae, medially rather widely and small reticulate-rugulose. Second and following tergites entirely smooth. Vertex almost entirely with very sparse, long and erect pale setae, sometimes glabrous posteriorly. Mesoscutum glabrous, with very long, sparse and almost erect yellowish setae arranged widely along margins of notauli and in single line laterally. Setae of hind tibia semi-erect, mainly long and rather dense, but dorsally in apical quarter additionally with dense and short setae; length of long setae on its dorsal surface 1.0–1.4 times maximum width of tibia. Colour. Body black or dark reddish brown to reddish brown partly, head and anterior third of mesosoma dark reddish brown, occasionally head almost entirely or behind eyes yellowish brown and mesosoma red in anterior half. Antennae brownish yellow or yellow in basal third, yellow medially, dark brown to sometimes black on apical six-seven segments. Palpi pale yellow. Legs almost black or dark reddish brown, fore femur apically, always all tibiae apically and all tarsi entirely (including fifth segment) light reddish brown to brownish yellow, middle coxa and sometimes middle trochanter and hind trochanter whitish. Ovipositor sheath brownish yellow or yellow, black apically. Fore wing strongly darkened, with faintly darkened spots basally and in middle of medial cell, with very faintly darkened to almost hyaline transverse stripes in beginning of pterostigma (narrow) and on apex of wing (wide). Pterostigma dark brown to black, pale yellow to whitish yellow in basal quarter. Male. Body length 2.4–4.3 mm; fore wing length 1.9–3.0 mm. Head width (dorsal view) 1.4–1.6 times its median length, 1.3–1.5 times width of mesoscutum. Head behind eyes (dorsal view) slightly roundness decreased. Malar space 0.35–0.4 times maximum diameter of eye. Face partly and finely striate-rugose, widely smooth laterally and below; its width 0.9 times maximum diameter of eye, almost equal to height of face and clypeus combined. Hypoclypeal depression width 0.5 times width of face. Antennae 26–35-segmented; brown to dark brown on apical 9–10 segments. Penultimate segment 3.7–4.3 times longer than their width, 0.6–0.7 times as long as first segment. Maximum length of mesosoma 1.9–2.1 times its maximum height. Scutellar sulcus (prescutellar depression) 0.2–0.4 times as long as scutellum. Propodeal areola sometimes with more long basal carina. Metacarp (R1) 1.25–1.35 times longer than pterostigma. Second radial abscissa (3RSa) 3.7–5.0 times longer than first abscissa (R), 1.15–1.30 times longer than first radiomedial vein (2RS). Hind wing 5.2–5.4 times longer than its maximum width. Hind femur 2.9–3.1 times longer than wide. Length of setae on dorsal surface of hind tibia 1.3–2.0 times maximum width of tibia. Hind basitarsus with distinct inner apical process. Second segment of hind tarsus 0.45–0.50 times as long as basitarsus, 0.8–0.9 times as long as fifth segment (without pretarsus). Length of petiole 3.4–3.9 times its apical width; apical width 1.8–2.0 times width at spiracle level, 2.0–2.3 times minimum subbasal width. Second-fourth tergites with laterotergites separated. Median length of second and third tergites combined 1.3–1.6 times its basal width, 0.75 times their maximum width. Sometimes body paler. Otherwise similar to female.

Mexico (Los Tuxtlas, Veracruz).