Oberthuerella triformis Quinlan

Buffington, Matthew L. & Noort, Simon van, 2012, Revision of the Afrotropical Oberthuerellinae (Cynipoidea, Liopteridae), ZooKeys 202, pp. 1-154 : 76-80

Oberthuerella triformis Quinlan Figures 37-38

Oberthuerella triformis Quinlan, 1979: 115.

Description.

Coloration of head and mesosoma black to dark brown; metasoma orange; fore- and midlegs black to dark brown, hindlegs with coxae dark brown, femora and tibia orange, tarsi dark brown.. Sculpture on vertex, lateral surface of pronotum and mesoscutum present, gently striate on vertex, pronotum, mesoscutum striate-foveate.

Head. Broadly triangular, in anterior view. Pubescence on head present, sparse setae scattered over head. Sculpture along lateral margin of occiput many costulae. Gena (measured from compound eye to posterolateral margin of head) short, ratio of length of gena to length of compound eye in dorsal view <0.3, in dorsal view. Sculpture of gena deeply striate. Lateral margin of occiput defined by distinctly angled, raised, sharp carina. Occiput (except extreme lateral margin) with distinct subvertical, slightly and evenly curved costulae. Ocelli small, ratio of maximum diameter of a lateral ocellus to shortest distance between lateral ocelli 0.2-0.4. Anterior ocellus close to posterior ocelli, posterior margin of anterior ocellus behind or subcontiguous with a transverse line running through anterior margins of posterior ocelli. Relative position of toruli close to ocelli, ratio of vertical distance between inner margin of torulus and ventral margin of clypeus to vertical distance between anterior ocellus and torulus <2.0. Median keel of face present, short, not extending beyond toruli. Vertical carina adjacent to ventral margin of torulus absent. Facial sculpture transversely striate with remnants of foveae. Facial impression absent, face flat. Antennal scrobe absent. Anterior tentorial pits small. Vertical delineations on lower face absent. Ventral clypeal margin laterally, close to anterior mandibular articulation, distinctly angled. Ventral clypeal margin medially emarginate. Clypeus horizontally striate. Malar space adjacent to anterior articulation of mandible evenly rounded, striate. Malar sulcus absent. Compound eye close to posterior ocellus, ratio of distance between compound eye and posterior mandibular articulation to distance between posterior ocellus and compound eye> 1.2. Compound eye, in dorsal view, distinctly protruding from the surface of the head, particularly laterally. Pubescence on compound eye absent. Orbital furrows absent. Lateral frontal carina of face absent. Dorsal aspect of vertex variously strigate. Posterior aspect of vertex with parallel or slightly radiating, longitudinal strigae. Hair punctures on lateral aspect of vertex present, distinctly enlarged. Posterior surface of head deeply impressed around postocciput.

Labial-maxillary complex. Apical segment of maxillary palp with pubescence, consisting only of erect setae. First segment of labial palp shorter than apical segment. Labial palp composed of three segments. Apical seta on apical segment of maxillary palp shorter than twice length of second longest apical seta. Erect setae medially on apical segment of maxillary palp present. Maxillary palp composed of four segments. Last two segments of maxillary palp (in normal repose) curved inwards. Distal margin of subapical segment of maxillary palp slanting inwards, apical segment bending inwards. Apical segment of maxillary palp more than 1.5 × as long as preceding segment.

Antenna. Articulation between flagellomeres in antenna connate with articles broadly joined. Female antenna composed of 11 flagellomeres. Female F1 shorter than F2; black. Flagellomeres of female antenna cylindrical, not widened towards apex, non-clavate. Placoidal sensilla absent. Distal flagellomeres of female antenna not conspicuously enlarged compared to proximal flagellomeres.

Pronotum. Macrosculpture on lateral surface of pronotum present, deeply costulate. Pubescence on lateral surface of pronotum present, sparse, composed of few short hairs. Anterior flange of pronotal plate distinctly protruding anteriorly, longitudinally striate. Carinae extending posteriorly from lateral margin of pronotal plate absent. Lateral pronotal carina present. Pronotal crest absent. Dorsal margin of pronotal plate (in anterior view) rounded. Submedian pronotal depressions closed laterally, shallow. Lateral margin of pronotal plate defined all the way to the dorsal margin of the pronotum. Width of pronotal plate wide, almost as wide as head.

Mesoscutum. Mesoscutal surface convex, evenly curved. Sculpture on mesoscutum present, deeply transversely costate. Notaulus present, wide, transversely striate, distinctly wider posteriorly. Median mesoscutal carina absent. Anterior admedial lines present, with adjacent cuticular surface horizontally striate. Median mesoscutal impression present, long, reaching over 1/2 length of mesoscutum. Parascutal carina distinctly sinuate, posteriorly ending in posteroventrally directed projection.

Mesopleuron. Horizontally strigulate, with striae converging on remnant fovea along posterior margin of sclerite. Subpleuron entirely smooth with few long white setae along ventral, posterior margins. Lower mesopleuron medially smooth, setose; costate laterally, ventrally. Epicnemial carina present on ventral half of mesopleuron; shagreen, ventrally bulbous near mesosternum. Lateroventral mesopleural carina present, marking abrupt change of slope of mesopectus. Mesopleural triangle absent. Subalar pit large and well defined, lying in posterior end of subalar groove. Speculum present, striate, with distinct smooth, glabrous ventral cavity. Mesopleural carina absent.

Scutellum. Dorsal surface of scutellum foveate-areolet. Circumscutellar carina absent. Posterior margin of axillula marked by distinct ledge, axillula distinctly impressed adjacent to ledge. Latero-ventral margin of scutellum posterior to auricula entirely smooth. Dorsoposterior part of scutellum produced posteriorly into blunt spine. Dorsal part of scutellum entirely areolate. Scutellar plate absent. Scutellar foveae present, three, with lateral foveal bissected by longitudinal carina, resulting in five longitudinally elongate subfovea. Longitudinal scutellar carinae absent. Single longitudinal carina separating scutellar foveae absent. Postero-lateral margin of scutellum drawn out into distinct protuberance. Lateral bar with strong strigate sculpture, narrow.

Metapectal-propodeal complex. Metapectal cavity anterodorsal to metacoxal base absent. Anterior margin of metapectal-propodeal complex seperated from mesopleuron by distinct dorso-ventral ledge. Posteroventral corner of metapleuron (in lateral view) rounded, not drawn out posteriorly. Anterior impression of metepimeron absent. Posterior margin of metepimeron distinct, separating metepimeron from propodeum. Subalar area slightly broadened anteriorly, without longitudinal division indicated. Calyptra present, blunt, lobe-like, polished posteriorly with setiferous punctures anteriorly. Dorsellum present with two strong medial fovea, glabrous. Anterior impression of metepisternum, immediately beneath anterior end of metapleural carina, absent. Pubescence consisting of few scattered hairs on posterior part of metapleuron and lateral part of propodeum. Propodeal spurs present, foveate. Lateral propodeal carinae present, not reaching scutellum. Ventral end of lateral propodeal carina terminating before reaching nucha. Inter propodeal carinae space glabrous, costulate. Petiolar foramen removed from metacoxae, directed posteriorly. Horizontal carina running anteriorly from lateral propodeal carina present. Lateral propodeal carina distinctly angled. Calyptra, in lateral view, rounded. Propodeum relatively short, not drawn out posteriorly. Calyptra, in posterior view, rounded.

Legs. Pubescence posterolaterally on metacoxa sparse to moderately dense, confined dense hair patch absent. Microsculpture on hind coxa absent. Longitudinal carina on the posterior surface of metatibia absent. Metafemoral spine present, elongate, extending distally as low keel along ventral femoral margin. Distal mesotibial spurs shorter than medial spurs. Distal metatibial spurs longer than medial spurs. Ratio of first metatibial segment to remaining 4 segments greater than 1.0. Pubescence on outer surface of metatarsal claw sparse, consisting of few setae. Outer surface of metatarsal claw microcarinate. Apical seta of metatarsal claw positioned on outer surface below dorsal margin. Base of metatarsal claw strongly expanded, apex strongly bent, ratio width of base to length of apex> 0.6; lammelate, with translucent cuticular flange.

Forewing. Pubescence of forewing present, sparse across entire wing surface. Apical margin of female forewing rounded. Rs+M of forewing tubular. Mesal end of Rs+M vein situated closer to posterior margin of forewing, directed towards posterior end of basalis. Vein R1 tubular along at least basal part of anterior margin of marginal cell. Basal abscissa of R1 (the abscissa between 2r and the forewing margin) of forewing as broad as adjacent wing veins. Coloration of forewing entirely lightly infuscate. Marginal cell of fore wing membranous, similar to other wing cells. Areolet absent. Hair fringe along apical margin of forewing absent.

Petiole. About as long as wide. Surface of petiole longitudinally costate, ventral keel absent. Posterior part of female petiole not abruptly widened. Ventral flange of annulus of female petiole absent.

Metasoma. Setal band (hairy ring) at base of tergum 3 absent, base of metasoma glabrous. Tergum 3 distinctly smaller than tergum 4. Posterior margin of tergum 3 smoothly rounded. Posterior margin of tergum 4 arcuate. In lateral view, sternum 3 encompassed by T6. Sculpture on metasomal terga present, dorsally finely punctate, posteriorly with distinct bands of setiferous pits. Syntergum absent, all postpetiolar terga free. Annulus absent. Peg-like setae on T6-T7 present. Postero-ventral cavities of female metasoma T7 present, setose. Female posteroventral margin of T6-T7 distinctly sinuate. Terebrum and hypopygium (in lateral view) straight, pointing posteriorly.

Ovipositor. First valvula of ovipositor narrowing gradually, not broadened apically, serrate at tip. Ovipositor clip absent.

Diagnosis.

Distinguished from other species of Oberthuerella by the extremely short median keel of the face, not reaching beyond the toruli; this is shared only with Oberthuerella lenticularis , but differs from this latter species by the very short scutellar spine, much shorter than the petiole (as long as the petiole in Oberthuerella lenticularis ).

Distribution.

Tanzania. Link to Distribution Map. [http://hol.osu.edu/map-full.html?id=181564]

Material examined.

Holotype, female: TANZANIA: Singida Reg., Misughaa (Mshughaa), 30mi E Singida, XII-1935 - I-1936, E. Burtt, BMNH HT 0010 (deposited in BMNH).