Distictus aurantium Santos & Aguiar

Santos, Bernardo F. & Aguiar, Alexandre P., 2008, Phylogeny and reclassification of Distictus Townes (Hymenoptera, Ichneumonidae, Cryptinae), with description of a new species, Zootaxa 1934, pp. 30-39 : 37-39

Distictus aurantium Santos & Aguiar , n. sp.

(Figs 7–12)

Etymology. From the New Latin aurantium , meaning orange; in reference to the mostly orange mesopleuron and propodeum..

Description. Lenght of fore wing 7.6–9.2 mm. Head (Figs 7–9): Antennae with 24–25 flagellomeres; clypeus small, 1.8 as wide as high; supra-clypeal area, mandible, and malar space near mandible, densely pilose; mandible length 1.0 as long as basal width, teeth of equal length; supra-antennal area ventrally concave, near ocelli convex, densely microsculptured; a short median carina from near ocelli to almost full length of supra-clypeal area, getting lower and wider between antennae, narrowing again on supra-clypeal area. Mesosoma (Figs 7, 9): Pronotum strongly striate around collar and near intersection with mesopleuron; epomia very weak, sometimes indistinct from rugulosities near collar; mesoscutum scarcely pilose, punctulate, central lobe on posterior half longitudinally rugulose, some punctate; notauli moderately impressed, parallel, reaching 0.4–0.5 of mesoscutum; scutellum as wide as long, shiny, impunctate or with very few and fine punctures; mesopleuron shiny, glabrous to moderately pilose, densely punctate except speculum, with strong striation below subalar proeminence and weaker striation irregulary distributed on ventral portion; epicnemial carina complete, uniformely arched forward; sternaulus sinuous, very weakly impressed; mesopleural fovea a very deep pit; upper division of metapleuron impunctate, with very weak striation on borders, densely pilose; lateral division (below propodeum) densely punctate and rugulose, ventrally scarcely to moderately pilose. Propodeum (Fig. 9): in dorsal view, about as long as wide; moderately pilose; area anterior to anterior transverse carina with very strong rugulosity, changing from centrally concentric to laterally reticulate; behind anterior transverse carina, reticulate rugulosity becoming progressively transversal towards apex; spiracle weakly oval, about 1.3 as wide as long; anterior transverse carina centrally curved forward, placed aproximately on mid-length of propodeum; propodeal apodeme distinct only on lateral view, or entirely absent. Wings (Figs 10, 11): Fore wing vein 1-Rs+M sligthly sinuous, bulla placed centrally; crossvein 1m-cu nearly straight, limit between the two veins distinct; ramellus absent; crossvein 1cu-a forming straight angle with vein M+Cu, ending basad of vein 1M+Rs; crossvein 2cu-a distinctly longer than vein 2-Cu, the two veins angled; vein 4-Rs straigth, somewhat irregular, apical portion upcurved; bulla of crossvein 2m-cu placed centrally; cell 1+2Rs (areolet) of moderate size, about 0.8–0.9 as high as maximum width of pterostigma, pentagonal, as wide as high, open, with crossvein 3r-m not diferenciated; veins 3-M and 4-M weak, almost spectral, 4-M distinctly longer than 4-Rs. Hind wing (Fig. 11) vein 2-1A weak, reaching 0.7 of the distance to posterior margin; vein 1-Cu of same length as crossvein 1cu-a; vein 2-Rs entirely tubular; crossvein 1r-m with bulla on ventral portion; apical part of vein M+Cu moderately convex; vein Cub straigth, ending close to wing margin. Metasoma (Figs 7, 9): first tergite stout, in dorsal view aproximately 1.75 as long as maximum width, triangular, apex 2.6 times the width of base, almost impunctate, shiny, without basal tooth; spiracle at the middle, not prominent; without longitudinal carinae except traces of dorsolateral carina; tergite 2 with coarse punctures, scarcely pilose, apex 2.1 as wide as base, thyridium as wide as long; tergites 3–4 finely microsculptured; then gradually changing from alutaceous on T5 to almost polished smooth on T8; tergites 5–6 aproximately the same size of tergites 7–8; ovipositor sheath dilated and spoon-shaped on its apical 0.3; ovipositor thick, straigth, its tip without nodus, with preapical notch, ventral valve with 8 apical teeth.

Color (Figs 7–9): Head black; mesosoma and metasoma mostly reddish orange; scape and pedicel ventrally dark brown, with ventral apex dark ferruginous (168,115,045), dorsally black; flagellomeres 1–3, and basal 0.4 of 4th, dark brown; apex of 4th and 5–10 dorsally white, ventrally dark brown; 11th dark brown with dorsal triangular white mark; 12–24 ventrally dark brown, dorsally black; center of clypeus, labrum, labial and maxilliary palpi except for ferruginous apical article, orbital band from inner top of the eye to near lower end of supra-clypeal area, and in about 0.6 of extension of temple pale yellow (208,223,168); supra-clypeal area black with yellow transverse marks extending from orbital band to center, covering 0.3–0.6 of its surface. Mesosoma and propodeum reddish orange (132,089,055); prothorax, mesoscutum, postscutellum, metanotum, upper 0.25 of anterior portion of mesopleuron and all mesopleuron anteriorly of epicnemial carina black, except yellow bands on collar, tegula, subalar proeminence and above fore coxa; scutellum, upper division of metapleuron and subtriangular spot at the area of propodeal apodemes yellow. Legs: fore and mid legs ferruginous (114,084,050), except fore coxa laterally and fore trochanters whitish, outer side of fore tibia darker; hind leg dark orange (156,100,051). Wings hyaline (Figs 10, 11), except fore wing with transverse, diffuse, subapical brown stripe (Fig. 10). Metasoma (Fig. 7): reddish orange (151,084,039), basal segments darker than apical ones, with very narrow yellow stripes at apex of T1–3 and T7–8, sternites lighter than tergites. Ovipositor dark brown, dorsal valve darker than ventral; sheaths dark brown, inner face light brown to yellowish.

Variability. The only female paratype has body generaly more pilose than the holotype; fore wing crossvein 1cu-a ending more basad of base of crossvein 1M+Rs, about 0.3 of its own length; also generally with darker tones of reddish and yellow; ventral side of flagellum and fore tibia very lightly colored; yellow orbital band on temple much longer, extending to base of mandible.

Male. General morphology and color similar to female (Fig. 13), except for having antenna with 26 flagellomeres, without white band; carina at supra-antennal area weak, not reaching supra-clypeal area; clypeus, face except black mark around lateral margin of clypeus, most or all gena and temple, prosternum and fore coxa pale yellow; basal 0.6 of mandible dark yellow to ferruginous; dorsal 0.4 of mesopleuron black; overall orange tones of mesosoma varying from bright (118,129,046) to dark (148,124,049); fore wing cell 1+2Rs higher than wide, crossveins 2r-m and 3r-m distinctly convergent; first metasomal tergite with yellowish stripe at apical 0.25; T2-4 black with pale yellow stripes at apical 0.3-0.4; T5-6 basally black, apical 0.5 dark orange to dark brown; T7 dark brown, apical 0.5 white.

Host. Unknown.

Comments. Female and male are readily differentiated from D. tibialis by having the mesosoma and propodeum mostly orange (vs. black with yellow marks); many characters of general morphology are also divergent (see description), particularly the absence of basolateral tooth at first metasomal segment (vs. present), and wing venation. Veins 2r-m and 3r-m of D. aurantium are less convergent than in D. tibialis , a difference which seems even more evident because cell 1+2Rs (areolet) is wider in D. aurantium .

Material examined. Two females, eight males. Holotype female ( UFES) BRASIL: Espírito Santo, Santa Maria de Jetibá: Fazenda Clarindo Kruger, 29.XI–06.XII.2002, Malaise trap, M. T. Tavares, C. O. Azevedo et al. Mounted on triangle point; hind left tarsomeres missing; left fore wing with a hole on cell 1+2R1, otherwise in good shape. Paratypes ( UFES) 1 ď; same data as holotype except “Faz. Paulo Seick-Área 1”; 1 Ψ; same data except “Domingos Martins, Mata Pico do Eldorado, 03-10.XII.2004, M. T. Tavares”; 2 ď same data except “Conceição do Castelo, Ribeirão do Meio, 17-24.III.2007, A. P. Aguiar et al. ”; 2 ď same data except “Santa Teresa, Estação Biológica Santa Lúcia, 09-13.V.2006, M. T. Tavares, C. O. Azevedo et al. ”. URU- GUAY: 2 ď ( AMNH) Depto Tacuarembó, 40 km NW Tacuarembó, 2-9.II.1963, J. K. Bouseman.

Distribution records. Known from five close localities in the highlands of Espírito Santo, southeastern Brazil, and one locality in northern Uruguay ( Fig. 6 ).

Figures

FIGURE 6. Maps with all known distribution records for species of Distictus. Left map, D. tibialis; right map, D. aurantium.