Electrostephanus (Electrostephanodes) petiolatus Brues, 2008

Engel, Michael & Ortega-Blanco, Jaime, 2008, The fossil crown wasp Electrostephanus petiolatus Brues in Baltic Amber (Hymenoptera, Stephanidae): designation of a neotype, revised classification, and a key to amber Stephanidae, ZooKeys 4 (4), pp. 55-64 : 57-60

Electrostephanus (Electrostephanodes) petiolatus Brues , combinatio revivisco

Electrostephanus petiolatus Brues, 1933: 14 [holotype male, in ill-fated Königsberg Collection, presumed destroyed]; Aguiar and Janzen, 1999: 444 [key]; Achterberg, 2002: 12 [mentioned in Schlettereriinae ]; Aguiar, 2004: 14 [catalogue].

Denaeostephanus petiolatus (Brues) , Engel and Grimaldi, 2004: 1194 [tentative transfer to genus based on description of petiole by Aguiar and Janzen (1999)]; Engel, 2005: 318 [mentioned].

Type material. Neotype (here designated) male; AMNH B-JWJ-260 , Baltic amber, Eocene (Lutetian), and labeled “ Neotype, Electrostephanus petiolatus Brues , desig. Engel & Ortega-Blanco [red label]”. Formerly part of the Jens-Wilhelm Janzen collection.

Diagnosis. As for the subgenus (vide supra).

Description. Male: Total body length (from head anterior margin to metasoma posterior margin) 9.84 mm; forewing length (from tegula to apex) 5.04 mm. Integument dark brown to black (where evident) with scattered, thin, simple, erect or suberect setae as noted. Head globular, with compound eyes occupying around onehalf of lateral surface, eyes well separated from preoccipital area; “crown” composed of 5 tubercles arising anterior to series of four transverse carinae between lateral ocelli around compound eyes, median ocellus set just anterior to series of carinae; tubercles arranged with anteriormost tubercle medial on frons, lateral tubercles paired in longitudinal series parallel to compound eye; integument of face rugulose, integument posterior to carinae and on gena impunctate and smooth. Antennae with 23 articles, arising from clypeus boundary at about compound eye midlength; scape about twice as long as wide, somewhat ovoid, surface bordering malar space slightly flattened; pedicel about one-half scape length, almost as wide as long; first flagellomere as long as pedicel but one-half width; second flagellomere around four times longer than wide, slightly less than twice length of first flagellomere; third through fifth subequal in length and shape; remaining flagellomeres progressively shorter, except apicalmost flagellomere with tapered apex. Maxillary palpus 5-segmented, elongate, elbowed between MP 2 (maxillary palpomere II) and MP 3, MP 1 and MP 2 thicker than MP 3–5, MP 1 shortest, MP 2 about twice length of MP 1, MP 3 slightly less than twice length of MP 2, MP 4 and MP 5 equal in length to MP 3. Labial palpus short, apparently 3-segmented (base obscured), slightly widening apically except LP 3 with acutely pointed apex.

Pronotum long, transversely striate along neck, near articulation with head, remainder of surface imbricate and irregular, laterally and dorsoventrally micro-rugulose, posterior portion with sparse, erect, long, simple setae; propleuron finely imbricate, with scattered shallow punctures. Mesoscutum, mesoscutellum, and metanotum apparently largely imbricate, with scattered shallow punctures (direct view of this surface slightly obscured), with sparse, erect, long, simple setae; pleura largely coarsely and irregularly punctured, punctures deep, large, and nearly contiguous, forming irregular network, except posterior half of mesopleuron with large, impunctate and imbricate area bordered posteriorly by dorsoventral column of coarse, large, punctures along boundary with metapleuron; metapleuron with longitudinal series of irregular rugae, posteriorly with coarse, irregular, contiguous punctures like those on anterior portion of mesopleuron except more deeply impressed.

Pro- and mesocoxae short and cylindrical, imbricate; metacoxa massive, wider at base, oriented posteriorly, imbricate except basally somewhat rugose; trochanters narrow at base, gently and slightly widening apically, with distinct trochantellus; femora finely imbricate; pro- and mesofemora with proximal thirds narrowly petiolate; metafemur fusiform, widest at mid-point; ventral surface of metafemur with a blunt, triangular, principal tooth at first third of length, a more acute and longer tooth near midlength, and a tooth near apex in apical third of length; three minor teeth or protuberances between medial tooth and others, such protuberances slightly closer to medial tooth, another protuberance just prior to distalmost principal tooth; a thin, long seta arising from each protuberance; metafemur with scattered, erect, long, slightly fuscous setae; tibiae finely imbricate, thin and elongate, with nearly basal halves narrowly petiolate, with a row of short spines on anterior and posterior surfaces of pro- and mesotibia; metatibia with several long setae at apex, inner surface with thin patch of microtrichia; tibial spurs 1-2-2, stout and short; metabasitarsus with a row of stouter setae anteriorly and posteriorly; remaining tarsomeres with two distinct long, thick distal setae; tarsal relative proportions – (all in comparison to associated basitarsus = 1) foreleg: 1: 0.5: 0.3: 0.3: 0.4; midlegs: 1: 0.4: 0.4: 0.3: 0.4; hind legs: 1: 0.4: 0.25: 0.8: 0.5; fourth tarsomere with distal ventral surface elongate, extending under most of fifth tarsomere; fifth tarsomere arising from near midlength of fourth tarsomere; pretarsal ungues (= claws) long, curved, and simple.

Wing membranes hyaline. Forewing with parallel-sided, dark brown pterostigma, slightly more than three times longer than high; Rs apex not reaching completely wing margin but extending well beyond pterostigma, demarcating a long, open marginal cell; basal vein (first free abscissa of M) arched proximally along basal half, about three times as long as first free abscissa of Rs, about twice 1m-cu length and approximately parallel to 1m-cu, demarcating a trapezoidal medial cell (= discal cell); Rs+M b and bullae absent; submarginal cell pentagonal, wider apically, r-rs slightly less than one-half length of second free abscissa Rs; cubital cell rectangular, three times longer than high; M and Cu almost reaching wing margin as nebulous veins; 3A, 2cu-a, and apical third of 2A nebulous; posterior margin of wing with very short, thin setae. Hind wing with four distal hamuli; only Sc+R present, thin and tubular.

Metasoma slender, elongate, terga and sterna not fused laterally, integument finely imbricate except pseudo-petiole rugulose, sternum with irregular transverse rugae ba-sally; first metasomal tergum and sternum forming a narrow, tubular pseudo-petiole (a “true” petiole in Stephanidae have the tergum and sternum fused laterally), about five times longer than wide; metasomal segments II–V subequal in length, remaining terga progressively shorter, second and third metasomal segments about three times longer than wide; gastral terga with exceptionally sparse setae, setae suberect, simple and long; gastral sterna with sparse, erect or suberect, elongate setae; parameres exposed, broad, tapering gradually to bluntly rounded apices, with fringe of dense, erect, moderate-length, slightly fuscous setae at apex.

Female: Unknown.