Megischus melanogladius Aguiar, 2006

Aguiar, Alexandre P., 2006, The Stephanidae (Hymenoptera) of Mexico, with description of six new species and key to western Foenatopus Smith, Zootaxa 1186, pp. 1-56 : 35-37

Megischus melanogladius Aguiar , sp. n.

( Figs 9–16 , 69–72 )

Etymology Greek melanos, black + Greek gladius, sword; in reference to the ovipositor sheath entirely black.

Description

Female. Holotype specimen. Body length 24.8 mm; biometric ratios in Table 1. Head: Antenna with 38 flagellomeres; f1–2 thick and slightly arched; f3–8 narrow and long, between 7.5–11.5 times longer than wide; f9–38 distinctly shorter, decreasing from 6.0 (f7) to 2.4 (f25) times longer than wide. Frons entirely, strongly, transversely areolaterugose; surface inside areolation polished; laterally and centro ventrally a few scattered hairs, decumbent downwards; along eye margins with line of numerous short hairs obliquely decumbent towards clypeus. Coronal area with irregular carinae more or less circularly surrounding central ocellum. Vertex ( Fig. 69 ) glabrous; three distinct sculpture patterns: anteriorly with 5–6 arched, concentric, progressively smaller carinae; centrally strongly strigate more or less in bell­shaped fashion; laterally and posteriorly densely and coarsely foveolate, some foveolae also mixing with central strigation; sculpture disappearing clearly before reaching occipital carina, leaving a narrow polished area; central impression absent; temple broadly polished; gena in dorsal view not prominent; mostly polished, but with sparse punctures with associated hairs. Occipital carina very narrow, width uniform; somewhat sunken into head; reflected towards head surface; ventrally almost reaching base of hypostomal carina, then reflected outwards, towards base of mandible, but disappearing a little before reaching it; laterally and dorsally with row of equidistant, small hairs along its length. Hypostomal area polished.

Mesosoma: Prosternum with weak pre­apical depression; covered with small but deep, well­delimited, approximately uniformly distributed foveolae, separated by about 1.0–1.5 times their diameter; surface in between weakly alutaceous. Pronotum ( Fig. 70 ): colo with 2 pairs of strong, strongly oblique carina, the anterior pair straigth, converging and practically meeting centrally; the posterior pair anteriorly greatly projected, partially curved backwards, posteriorly convergent, to end widely separated, over an area equivalent to the location of the pronotal fold. Pronotal fold replaced by a wide, polished area representing a deep oblique constriction between colo and preannular. Preannular crossed by stout, tall, polished, transverse rugosity. Femoral impression from posteriorly narrow and deep to anteriorly wide, widely opening on, and becoming indistinct of, dorsolateral part of semiannular; posteriorly smooth, anteriorly taken by semiannular rugosity; ventral area anterior end as a wide flange hanging over channel created by the deep pronotal constriction, then strongly transversely carinate untill approximately mid­length, then shifting to longitudinally strongly rugose and progressively to posteriorly densely longitudinally strigate. Semiannular centro laterally polished with a few foveolae, otherwise transversely strongly rugose with some foveolae in between. Mesoscutum median sulcus indicated by a faint, straight groove, more distinct posteriorly, indistinct anteriorly, notaulus indistinct, lateral lobes from laterally transversely strongly areolaterugose to mesally foveolate. Axilla lateral margin with a deep foveola, posterior half densely foveolate, anteriorly faintly alutaceous. Scutellum mostly faintly alutaceous, marginally with widely scattered, well defined subcircular foveolae, laterally with a submarginal groove. Mesepisternum with moderately dense foveolation, the foveolae separated by about their diameter, except centrally more separated, by about 1.5 diameter; each bearing one long hair; surface in between polished. Mesopseudosternum polished; discrimen fully crenulate, but progressively changing from very small crenulations anteriorly to large posteriorly. Propodeum with many medium­sized, circular, well defined foveolae, densely distributed antero­centrally, also more frequent along spiracular groove, laterally sparse; surface between foveolae conspicuously alutaceous, the foveolae polished inside; posteriorly with a few strong, transverse, parallel rugosities near petiolar foramen; laterally, behind spiracle, changing to areolate­rugose and foveolate, almost completly obliterating parapetiolar fovea. Spiracular groove distinct, but fully crossed by weak rugosity; spiracular carina strong, straight; both carina and groove ending near crenulate sulcus; area lateral to carina broadly weakly alutaceous. Metapleuron centrally coarsely areolate­rugose, with long pilosity associated with areolae, plus sparse short pilosity in between; ventrally, including post­foveolar area, pleuropropodeal fovea and extending to interfoveolar area, polished. Hind coxa latero­basally with some foveolae, laterally with weak transverse elevations, each bearing one long hair on its posterior face, the hairs strongly inclined towards apex; dorsally weakly transversally rugose; ventrally mostly polished; mesally flattened, on ventral half with dense ventrally decumbent short hairs. Hind femur apical tooth longer than central tooth. Hind femur and dilated portion of hind tibia ( Fig. 72 ) distinctly alutaceous, strongest on tibia; compressed portion of hind tibia very weakly alutaceous, almost polished; femur and tibia covered with short, sparse pilosity, decumbent towards apex, each hair not reaching the base of the next; hind tibia basal 0.35 laterally compressed ( Figs. 71, 72 ), its ventral margin round.

Metasoma: Petiole densely weakly transversely strigate, latero­ventrally almost polished. T3–8 (2 nd to 7 th metasomal) microscopically transversely sculptured (very fine but distinct pattern); T9 microreticulate. Pygidial sulcus U­shaped, but also with a short longitudinal depression extending from its base over T9; pygidium narrow, its apical margin strongly sclerotized.

Color. Body mostly dark brown with weak reddish tint (065,039,030), except hind trochanter and tibia, propodeum and petiole red brown (149,046,006), and all tarsi with tendency to orange brown (178,120,031). Antenna scape, pedicell and f1–2 black, f3–8 orange brown, from f9 to apex dark brown as most of the body. Wing membrane pale amber (244,246,218), veins dark brown. Ovipositor sheath externally black with violaceous reflections; its lumen pale yellow, almost white.

Comments

This species can be readily recognized by the association of its pronotum anteriorly with a deep polished constriction ( Fig. 69 ) ( bicolor group); hind tibia posteriorly with undifferentiated compression ( Figs 71, 72 ) (further isolating it from the brunneus group); propodeum finely and distinctly alutaceous between foveolae; and the monocolorous ovipositor sheath. It is most likely related to M. bicolor .

MALE. Unknown.

Material examined Holotype ♀ EBCC “ Mexico, Jalisco, 3 Km O del Km 32.8, carretera 200, 4­VII­1995, R.L. Westcott, OSUC22870 [barcode, plastic].” Complete, well preserved.

Figures

FIGURES 9–16. Values of morphometric ratios for all examined female specimens of all species of Mexican Megischus. Species grouped in the Y­axis according to their order of appearance and morphological similarity in the key to species; key structure also indicated by the dendrogram applied to Y­axis of Figure 9. Legends for all graphs: an, M. anaxeus, sp. n.; az, M. arizonicus; bc, M. bicolor; cl, M. celaenocephalus, sp. n.; jc, M. jaliscoensis, sp. n.; ml, M. melanogladius, sp. n.; mx, M. mexicanus, sp. n.; ng, M. niger; pn, M. peninsularis, sp. n.; tx, M. texanus. For ratio abbreviations, see text.

FIGURES 69–72. Megischus melanogladius, sp. n., holotype ♀. 69, head, dorsal; 70, pronotum and anterior part of mesonotum, dorsal; 71, hind left tibia, lateral; 72, same, detail of central compression.