Eoeustochus Huber

Huber, John T. & Greenwalt, Dale, 2011, Compression fossil Mymaridae (Hymenoptera) from Kishenehn oil shales, with description of two new genera and review of Tertiary amber genera, ZooKeys 130, pp. 473-494 : 474-475

Eoeustochus Huber gen. n. Figs 18

Description.

Female. Body length 718-1133 (seven specimens in total, only four described and named to species). Head. Normal in shape, wider than long and about ¾ as high as wide. Face slightly convex in lateral view; vertex flat and slightly sloping anteriorly, forming a moderately sharp angle with occiput; back of head slightly concave. Eye higher than wide, about 2/3 head height; malar space about 1/3 eye height. Antenna. Funicle 6-segmented, with each funicle segment longer than wide; clava 3-segmented with the claval sutures perpendicular to claval length. Wings. Fore wing wide, symmetrical, with evenly rounded apex (shape resembling that of the extant genus Eustochus ); marginal fringe shorter than fore wing width. Venation about 0.4 × fore wing length, with long marginal vein and short but distinct stigmal vein. Hind wing narrow; marginal fringe much longer than wing width. Mesosoma. Shorter than gaster. Pronotum length at most about half length of mesoscutum. Mesoscutum length subequal to scutellum. Scutellum with frenum apparently entire, not divided longitudinally. Metanotum much shorter than scutellum. Metasoma. Constricted at base, probably with short petiole. Gastral terga similar in length. Ovipositor moderately short, probably arising near midpoint of gaster and its apex not or barely exserted beyond gastral apex.

Type species.

Eoeustochus kishenehn Huber, sp. n.

Derivation of generic name.

The name is from eo-, Greek for early, and Eustochus , an extant genus. The gender is masculine.

Discussion.

Two species are described, each from two specimens. Three additional specimens (Kishenehn #30,356, 40,410, and 40,023) belong to Eoeustochus but are not included in the type series of either species because they are not in as good a condition.

The relationships of Eoeustochus are with Eustochus , one extant species of which has a 3-segmented clava in females. Although thirteen extant genera have a definite 3-segmented clava ( Allanagrus , Anneckia , Idiocentrus , Krokella , Nesopatasson/Nesomymar , Neostethynium , Notomymar , Paracmotemnus , Parastethynium , Polynemoidea , Pseudocleruchus , Stethynium ), the closest one is Eustochus , based on the apparent strong constriction in lateral view between meso- and metasoma (none in Allanagrus ), transverse sutures between claval segments (sutures oblique in Stethynium ), shape of fully developed wings (wings almost absent in Nesopatasson / Nesomymar and Notomymar , and of different shape in Anneckia , Neostethynium , Parastethynium and Pseudocleruchus ) venation shorter than half fore wing length (venation longer in Krokella and Paracmotemnus ), and ovipositor not distinctly exserted beyond apex of gaster (ovipositor strongly exserted in Polynemoidea ) or projecting anteriorly under mesosoma (ovipositor strongly projecting anteriorly in Idiocentrus ).