Stauropoctonus excarinatus (Cushman)

Lima, Alessandro Rodrigues, Jacobi, Claudia Maria & Kumagai, Alice Fumi, 2013, Review of the Neotropical species of Stauropoctonus Brauns, 1889 (Hymenoptera: Ichneumonidae: Ophioninae), Zootaxa 3750 (5), pp. 494-514 : 501-503

Stauropoctonus excarinatus (Cushman)

( Figs 2 , 5 A–G, 9E–H)

Aulophion excarinatus Cushman 1947: 459 –460. Holotype ♂, Venezuela, San Esteban (AEI) [examined through images] Stauropoctonus excarinatus (Cushman) Gauld, 1985: 146 –149.

Type locality. Venezuela, San Esteban, near Puerto Cabello (Cushman, 1947).

Diagnosis. Body yellow; antenna brown; wings hyaline; pterostigma and fore wing vein Rs+2r brown. Gena in lateral view trapezoidal ( Fig. 5 C). Epicnemial carina absent on mesopleura. Strongly inflated scutellum ( Fig. 5 D), in lateral view forming two different faces (dorsal and posterior). Fore wing marginal cell with a conspicuous pilose proximal region ( Fig. 5 F). Fore wing vein cu-a reaching M+Cu basad of Rs&M ( Fig. 5 E–F). Hind tarsal claws long, with pectinae increasing in height towards apex.

Redescription. Males. Mandible slender, apically strongly compressed and twisted about 90°, with outer tooth acute, as long as inner one; outer mandibular surface with a shallow concavity crossing mandible at basal boundary of compressed area. Labrum about 0.25x as long as wide basally. Malar space about 0.25x as long as basal mandibular width. Clypeus weakly convex in lateral view, with margin truncate, about 1.3x as broad as long. Face alutaceous with setae equally distributed. Gena in lateral view trapezoidal ( Fig. 5 C). Lateral ocellus contiguous with eye. FI = 49–57%. ECI = 0.69–0.98. Occipital carina absent. Antenna with 58–60 flagellomeres; twentieth flagellomere nearly 2.3x as long as broad.

Mesoscutum polished, densely pilose, evenly rounded in lateral view; without notaulus. Mesopleuron polished, pilose; alutaceous below and smooth above mesopleural furrow, with a conspicuous glabrous region anterior to speculum. Epicnemial carina interrupted centrally on sternum; absent on pleuron. Scutellum smooth and shiny, as long as anterior width; strongly inflated ( Fig. 5 D); without lateral carina; in lateral view forming two different faces (dorsal and posterior). Metapleuron weakly convex, alutaceous. Submetapleural carina weakly broadened anteriorly. Posterior transverse carina of mesosternum reduced to lateral vestiges. Propodeum densely pilose, abruptly declivous in lateral view; anterior transverse carina not touching lateral longitudinal carina, from complete to either interrupted at lateromedian portions or almost completely inconspicuous; posterior transverse carina reduced to lateral vestiges; median longitudinal carina present, discernible on most of its way from anterior transverse carina to propodeum apex; anterior area longitudinally rugose; posterior area weakly rugulose; lateral longitudinal carina complete.

Fore wing length 14–15.4 mm; AI = 0.53–0.83; CI = 0.35–0.64; ICI = 0.77–1.25; SDI = 0.89–1.0; SRI = 0.41– 0.53; vein cu-a reaching M+Cu basad of Rs&M ( Fig. 5 E–F). Discosubmarginal cell ( Fig. 5 F) with a glabrous area anteriorly, from pterostigma to half length of vein Rs+2r which is curved and thickened on its basal third; 1m-cu abruptly curved at middle, almost straight at basal half, weakly convex at distal half, with a small but distinct ramellus. Marginal cell with a conspicuous pilose basal region ( Fig. 5 F). Hind wings R1 with 3–6 hamuli; Rs with basal half of first abscissa weakly bowed, distal half and second abscissa clearly straight; BCI = 0.46–0.53; basal abscissa of Cu1 about 2–4 times as long as cu-a.

Mid leg with outer tibial spur 1.1x as long as inner one. On hind leg, coxa in lateral view 1.85–2.0x as long as maximum width, at middle; fourth tarsomere about 3x as long as broad apically; claws long, with pectinae increasing in height towards apex.

Metasoma long and slender. Tergite 2 in lateral view 3.4–3.8x as long as posterior width; laterotergite pendant; thyridium oval, separated from anterior margin by about 5x its length. Genitalia with gonostipes fused dorsobasally ( Fig. 9 G); gonocardo fused to gonostipes without ventral apophysis ( Fig. 9 E–G); gonostipes with very deep dorsal longitudinal sulcus which has dorsal inner face punctuated ( Fig. 9 F–G); apical indentation of gonostipes lozenge ( Fig. 9 E, C); gonostipital arm acuminate; gonolacinia with short spines concentrated in a single region; distivolsella spatulate. Aedeagus stem ( Fig. 9 H) is gradually thickened to apex, reaching maximum width at half its length; in lateral view, dorsal surface is curved upwards, the ventral one is angular, forming a corner. Aedeagus apical process forms a right angle with the stem dorsal line in lateral view; the ventral apical edge is curved and strongly projected, while the basal edge is strongly angular.

Head, thorax and coxa yellow. Antenna brown, gradually darkened towards apex. Mesoscutum with three wide brown fasciae. Metasoma and legs beyond coxa brown; apical half of tergite 3 and posterior tergites infuscate. Wings hyaline, pterostigma and fore wing vein Rs+2r brown.

Females. Similar to males, varying in the following: FI = 40–58%. Antenna with 58–62 flagellomeres. Fore wing length 15.2–16.3 mm. ICI = 1.1–1.2. SRI = 0.39–0.45. Tarsal claws more closely pectinate. Ovipositor straight and slender ( Fig. 5 G); dorsal subapical notch with two steps-like sculpture on its apical rim inner surface; with 4 teeth on lower valve apex.

Variation. The ramellus varies in size and in some specimens is indiscernible. Females have propodeal carinae more evident and tarsal claws with pectinae more uniform, without variation in height towards the apex. One of the males has the fore wing cu-a vein reaching M+Cu opposite of Rs&M. The specimen from Santa Catarina is darker than the others. The Amazonas specimen has more brownish body, and only weakly darkened metasomal tergites.

Comments. Stauropoctonus excarinatus closely resembles S. leotacilioi sp. n., which was also collected in the Southeast and South of Brazil. The comparison of the genitalia (shape of the aedeagus and gonostipes) was central to define the limits between these two sympatric species. The most evident characters to key these species are the scutellum, strongly inflated in S. excarinatus ( Fig. 5 D) and very weak in S. leotacilioi sp. n. ( Fig. 7 D); and the color pattern, with antenna, fore wing pterostigma and Rs+2r vein brown in S. excarinatus and black in S. leotacilioi sp. n.

Distribution. Stauropoctonus excarinatus , first known only to Venezuela (Holotype), is now recorded in Brazil: Amazonas, Minas Gerais and Santa Catarina states.

Material examined. Holotype (♂). Venezuela, San Esteban, 20.xii.1939, P.J.Anduze col. [AEI, examined through images made by Dr. Wahl]. [Information from original description].

Non types (6♀, 10♂). Brasil: Amazonas, Querari, (Pelotão) 1°5'N / 69°51'W, 21–22.iv.1993. Motta, C., Ferreira, R., Vidal, J. & Matteo, B. col. Luz mista de mercúrio e luz negra BL e BLB [1♀, INPA]. Minas Gerais, São Gonçalo do Rio Abaixo (Est. Amb. Peti / Cemig), 14–16.v.2010, Kumagai, A.F. col. [3♂, UFMG]; (Pennsylvania) 19°53'02"S / 43°22'21"W. A.Lima, A.Kumagai & P.Dias col., 28.iv–01.v.2012 [1♂, UFMG]; idem, 14–21.v.2012 [1♂, UFMG]; idem, 11–18.vi.2012 [1♀, UFMG]; idem, 11–18.x.2012 [4♂, UFMG]; idem, 09– 16.xi.2012, [1♀, UFMG]; idem, 10–17.xii.2012 [2♀, 1♂, UFMG]; Santa Catarina, Joinvile, 4.viii.1971, Miers [1♀, DZUP].

Figures

FIGURE 2. Species records of Stauropoctonus in the Neotropical Region.

FIGURE 5. Stauropoctonus excarinatus. A. Female body, lateral view. B – C. Head. B, frontal view; C, lateral view. D. Mesotorax, laterodorsal view. E. Wings, dorsal view. F. Discosubmarginal cell in detail, dorsal view. G. Female metasomal apex, lateral view. Scale in millimeters.

FIGURE 7. Stauropoctonus michelle sp. n. (A – B, D: Holotype; C, E – F: Paratypes) A. Female body, lateral view. B – C. Head. B, frontal view; C, lateral view. D. Wings, dorsal view. E. Discosubmarginal cell in detail, dorsal view. F. Female metasomal apex, lateral view. Scale in millimeters.

FIGURE 9. Male genitalia of Stauropoctonus sp. (A – D): A, ventral view; B, lateral view; C, dorsal view; D, Aedeagus, lateral view. S. excarinatus genitalia (E – H): E, ventral view; F, lateral view; G, dorsal view; H, Aedeagus, lateral view. Stauropoctonus michelle sp. n. genitalia (I – L): I, ventral view; J, lateral view; K, dorsal view; L, Aedeagus, lateral view. Gonostipes (Gst.); gonocardo (Gc.); ventral apophysis (Va.); dorsal longitudinal sulcus (Dls.); gonostipital apical indentation (Gai.); gonostipital arm (Gst. A.); gonolacinia (Gl.); distivolsella (Dv.); apical process of aedeagus (Ap.); Aedeagus stem (As.). Scale bar = 0.5 mm.