Electrostephanus brevicornis Brues, 1933

Ge, Si-Xun, Jiang, Zhuo-Heng, Ren, Li-Li, van Achterberg, Cornelis & Tan, Jiang-Li, 2023, New insights into the phylogeny of Stephanidae (Hymenoptera: Apocrita), with a revision of the fossil species, Arthropod Systematics & amp; Phylogeny 81, pp. 819-844 : 819

† Electrostephanus brevicornis Brues, 1933

Figures 11 , 12 , 13

Electrostephanus brevicornis † Electrostephanus brevicornis Brues, 1933:14 [holotype male, deposited in Königsberg Collection and presumed to be destroyed]; Aguiar and Janzen, 1999: 444-451 [keyed and discussed]; van Achterberg, 2002:11 [mentioned]; Aguiar, 2004:14 [catalog]; Engel, 2005:320 [discussed]; Engel and Ortega-Blanco, 2008:62 [keyed]; Li et al., (2017):196 [listed].

Type material.

Neotype (designated here) ♀; BFU, Baltic amber; Eocene. Labeled as "Neotype: † Electrostephanus brevicornis Brues designator: Ge and Tan." Part of the Si-Xun Ge collection.

Diagnosis.

Forewing with vein R and vein A with setae at least along basal half of their length; vein r-rs distinctly shorter than 2-Rs (Fig. 12B ); vein 2-Rs with its sub-median part slightly angled; vein 2Rs+M extremely short, slightly incision at the origin of veins 2-Rs and apical abscissa of vein M; vein 2Cub present. Metasoma tergum I and sternum I not fused (Fig. 11C ; Fig. 12C ). Tergite I about as long as Tergite II. Hind coxa strong, largely smooth and spindle shaped without striate. Hind femur tridentate; hind tarsus with five tarsomeres.

Description.

Female. Total body length (from head anterior to metasoma distal margin, without ovipositor sheath) 6.5 mm; forewing length 4.3 mm; remaining part of ovipositor sheath 2.9mm. - Head: Antenna with 21 flagellomeres; the first flagellomere short and robust, and second flagellomere slender; Head globular, with compound eyes occupying about half portion of lateral surface; vertex with five tubercles; temple slightly bulging, smooth and shiny; occipital carina distinctly developed but not connected to hypostomal carina; hypostomal carina large. Maxillary palpus 5-segmented, elongate, elbowed between MP II (the second maxillary palpomere) and MP III. - Mesosoma: Pronotum robust with neck distinctly differentiated; neck at almost same level than middle part of pronotum postero-dorsally; middle and posterior part of pronotum with transverse carinae (as laterally) and with distinct oblique lateral groove; middle part of pronotum weakly differentiated from posterior part; posterior part of pronotum and mesonotum with sparse setosity; propleuron coriaceous; scutellum invisible. - Wings: Forewing with vein 1-M distinctly curved, 2.5 × as long as vein 1-Rs and 1.3 × vein 1m-cu; vein R with setae along all its length, while vein A only on the basal half; Four short, erect, equidistant spiny setae distinctly developed on the basal part of vein 1Cu; vein 2-Rs 2.2 × as long as vein r-rs; vein r-rs ends inner side of pterostigma behind the level of apex of pterostigma; parastigmal vein (pv) elongated, ca 0.3 × as long as pterostigma; vein 2-Rs with its sub-median part slightly upcurve angled; vein 2Rs+M extremely short 0.2 × as long as vein 2-Rs, slightly incision at the origin of veins 2-Rs and apical abscissa of vein M; vein 2Cua distinct and curved apically with 2Cub distinctly developed. - Legs: Hind coxa robust, smooth and shiny, spindle shaped without transversely striate; hind femur coriaceous, fusiform with its widest part near mid-point; ventral surface of hind femur with its basal tooth relatively small and blunt, a more acute triangular tooth developed near mid-length, and a widest tooth at the distal part; ca. four minor teeth or protuberances between medial tooth and distal tooth; hind tibia elongate and 1.1 × longer than hind femur, with its basal narrow part 1.15 × as long as apical widened part, inner side of widened part basally shallowly depressed; hind tarsus with five tarsomeres; basitarsus 6.4 × as long as wide. - Metasoma: Tergite I finely imbricate, 2.7 × as long as its widest part, with tergum I and sternum I not fused; tergite I at least 1.2 × as tergite II. Remainder of metasoma largely not preserved; pygidial area distinctly protruding apically. Basal half of ovipositor sheath missing, remaining parts of ovipositor sheath ca 0.9 × as long as metasoma. Ovipositor tip laterally compressed, without distinct teeth apically.

Remarks.

The holotype of † Electrostephanus brevicornis Brues, 1933, has been lost ( Aguiar and Janzen 1999; Engel 2008). Since there are few figures for this species to date, the only basis of species designation is the original description by Brues (1933). Our neotype fits well with the original description except for a few characteristics as follows: 1) in the original description of Brues (1933), the vein 2Rs+M (= Rs+Mb) is absent and there is no incision at the origin of vein 2+3Rs (= 2-Rs) and/or 2+3M (= M), while in the neotype, an extremely short vein 2Rs+M (= Rs+Mb) and slight incision between the origin of veins 2-Rs and apical abscissa of vein M; 2) in the original description, the veins 2Cua and 2Cub are absent while in the neotype they are distinctly developed. However, we noticed that researchers may differ in describing the same characteristic. For instance, when the vein 2Rs+M (= Rs+Mb) is relatively short, it has often been considered absent, even in the original description of † Protostephanus ashmeadi Cockerell, 1906. Aguiar and Janzen (1999) pointed out that Brues did not regularly differentiate between nebulous and tubular veins, and merely chose to indicate their presence or absence. Furthermore, there were inevitably few morphological differences between the sexes (the holotype was male and the neotype is female). The missing type specimen and superficial original description greatly impede the understanding of the phylogeny of Stephanidae . Therefore, we ignore the subtle differences and designate this female as neotype of † E. brevicornis (Brues, 1933).

Figures

Figure 11. Electrostephanus brevicornis Brues, 1933. Neotype ♀. A Head and mesosoma, anterior-oblique view. B Wings. C Tergite I. D Ovipositor sheath. E Hind leg.

Figure 12. Details of Electrostephanus brevicornis Brues, 1933. Neotype ♀. A Head, anterior-oblique view. B Wings. C Metasoma as preserved. D Hind leg.

Figure 13. Habitus of neotype ♀. Electrostephanus brevicornis Brues, 1933. A Photo of specimen. B Line drawing of habitus.