Electrofoenops diminuta, Engel, 2017

Engel, Michael S., 2017, New Evanioid Wasps from the Cenomanian of Myanmar (Hymenoptera: Othniodellithidae, Aulacidae), with a Summary of Family-Group Names among Evanioidea, American Museum Novitates 2017 (3871), pp. 1-28 : 16-19

Electrofoenops diminuta , new species

Figures 6–7

DIAGNOSIS: As for genus (above).

DESCRIPTION: ♀: Total length as preserved (excluding antennae and stub of ovipositor: ovipositor broken at surface of amber near its base and therefore almost entirely missing) 4.50 mm; forewing length 3.25 mm; integument largely black to dark brown (where not augmented by preservation), largely glabrous, without pronounced sculpturing or punctation (except where noted below), largely faintly and finely imbricate; outer and upper surfaces of mandible, gena, and postgena with scattered, elongate, fine setae (fig. 6A); wings clear and hyaline, veins brown. Head broad, much wider than long, width (across compound eyes) 1.05 mm, length (to apex of clypeus) 0.75 mm; occipital carina complete; gena broad but narrower than compound eye; malar space narrow, short, length much less than basal mandibular width; compound eye large, prominent, almost circular, only slightly ovoid, bare (i.e., without setae between ommatidia), without circumocular carina, inner margins parallel, compound eye length 0.55 mm, width 0.50 mm, interocular distance 0.63 mm; ocelli small, arranged in small triangle on top of vertex above compound eyes, median ocellus separated from lateral ocelli by less than one ocellar diameter, lateral ocelli separated by approximately 1.5× their diameter and from ocular border by slightly more than twice their diameter. Antennal toruli broadly separated, situated near base of clypeus and at lower tangent of compound eyes; scape robust, about 2.7× as long as pedicel, longer than first flagellomere; flagellum filiform, with 12 flagellomeres; flagellomeres each longer than wide, ranging in lengths from 1.8–2.6× individual widths except apicalmost flagellomere, which has a length 3× its width; first flagellomere slightly longer than one-half length of scape; apical flagellomere slightly longer than first flagellomere. Clypeus short, with apical margin sinuate. Mandible long, length 0.40 mm, strongly projecting (fig. 6A), outer margin in apical half broadly arched inward, tridentate (two triangular teeth along length and large apical tooth).

Mesosoma longer than high, length 1.38 mm, maximum height 1.25 mm; pronotum without defined, raised posterior dorsal surface bordering mesoscutum, posterior border broadly concave, lateral surfaces large; prothoracic spiracle covered by rounded knob on posterolateral margin of pronotum; mesoscutum without transverse carinae or striae except for prominent carina along anterior border, notauli deeply impressed and Y-shaped, mesoscutal length 0.70 mm; mesoscutellum scarcely arched in profile, medial length 0.42 mm; mesopleuron areolate ventrally, with single row of faint areolae along border with metepisternum; metanotum areolate, subvertical, short, length 0.09 mm; propodeum areolate, with prominent dorsal surface, dorsal length (between metanotum and articulation with metasomal petiole) 0.14 mm. Legs long, with slender podites; tibial spur formula 1-2-2, spurs prominent; pro- and mesotrochantelli distinct but fused to associated femora; metacoxal longitudinal groove faint; metacoxa without distal lobe; metatrochanter with dorsolateral groove; metatrochantellus present but somewhat indistinct; metafemur length 1.25 mm, metatibia length 1.30 mm; metabasitarsus elongate but shorter than combined lengths of remaining tarsomeres, metabasitarsus length 0.70 mm, lengths of remaining tarsomeres (from base to apex), 0.25 mm, 0.15 mm, 0.09 mm, and 0.10 mm; pretarsal claws small, simple; arolium minute. Forewing (fig. 7) with narrow costal space of comparatively consistent width along its length, narrower than pterostigma; pterostigma longer than wide, expanded in width medially, tapering gradually in width to acute apex, margin inside marginal cell comparatively straight; 1cu-a basad M-Cu fork, thus short 2M+Cu present prior to bifurcation of veins; 1Rs elongate, slightly arched; 1M exceedingly short, about as long as 2M+Cu and 1m-cu; 1Rs+M straight, slightly shorter than 2Rs+M; 2Rs straight, distinctly angled relative to 2Rs+M; r-rs originates at widest part of pterostigma (slightly distad pterostigmal midlength), elongate, longer than 3Rs but slightly shorter than 2Rs; marginal cell broad, with greatest width anteroposterior breadth near rs-m, elongate, separated from wing apex by distance equal to one-half length of pterostigma; rs-m nebulous; second submarginal cell large but much smaller than massive first submarginal cell, second submarginal cell pointed basally; discal cell narrow, above level of M+Cu; 1m-cu straight and parallel to 1M; 2m-cu present but weakened (thin); 2A1 and 2cu-a present as infumate veins, enclosing subdiscal cell; subdiscal cell quite large and strongly pointed posteriorly. Hind wing without venation except C+R, with three distal hamuli near termination of R; without jugal lobe.

Metasoma ovate in profile, longer than mesosoma, length 1.5× length of mesosoma; tergum I and II fused, forming stocky, triangular petiole; ovipositor and sheaths only preserved within basal extremes (cut off at surface of amber).

Ƌ: Unknown.

HOLOTYPE: ♀, (fig. 6B), JZC Bu-60; Cretaceous amber (Cenomanian), Myanmar, Kachin, Tanai Village on Ledo road 105 km NW of Myitkyna; Zigras collection, available through and for permanent deposition in the Division of Invertebrate Zoology , American Museum of Natural History , New York.

ETYMOLOGY: The specific epithet is derived from the Latin, diminutus (meaning, “lessened”), in reference to the smaller size of the species relative to Electrofoenus gracilipes Cockerell, 1917b .

Figures

FIGURE 6. Microphotographs of holotype female (JZC Bu-60) of Electrofoenops diminuta, new genus and species, in Burmese amber. A. Facial view. B. Left lateral habitus.

FIGURE 7. Forewing venation of holotype female (JZC Bu-60) of Electrofoenops diminuta, new genus and species, with pertinent veins labeled.