Shoushida regilla

Liu, Chenxi, Shih, Chungkun & Ren, Dong, 2009, The earliest fossil record of the wasp subfamily Pelecininae (Hymenoptera: Proctotrupoidea: Pelecinidae) from the Yixian Formation of China, Zootaxa 2080, pp. 47-54 : 49-52

publication ID	https://doi.org/ 10.5281/zenodo.187339
DOI	https://doi.org/10.5281/zenodo.6215171
persistent identifier	https://treatment.plazi.org/id/03FA9A53-FFBA-172B-FF13-F99CFF5840ED
treatment provided by	Plazi
scientific name	Shoushida regilla
status

Treatment

Shoushida regilla gen. et sp. nov.

( Figs.1–4 View FIGURE 1 View FIGURE 2 View FIGURE 3 View FIGURE 4 )

Etymology. The specific epithet is derived from the Latin ‘ regilla ’; meaning honorable and distinguished, in praise of the Capital Normal University.

Holotype. CNU –HYM–LB2006074. A complete insect except for missing part of legs and part of left wing.

Type locality and horizon. Collected from Huangbanjigou Village, Beipiao City, Liaoning Province, China, the Yixian Formation.

Diagnosis. Same as those for the genus.

Description. Female (Male unknown). Head comparatively large (relative to the mesosoma), broadly transverse, oval; compound eye large (relative to the head), oval, occipital carina very well developed; antenna with 14 segments, filiform, scape trapezoidal, thinner basally and thicker apically; pedicel very short and trapezoidal; flagellomere cylindrical, the first flagellomere more than two times longer than scape and pedicel combined; subsequent flagellomeres also cylindrical and homonomous, with slightly decreasing length, but terminal flagellomere slightly longer than the preceding segment and rounded apically.

Pronotum comparatively short dorsally (relative to the mesosoma); mesoscutum with notauli, notauli oblique, arched, long and reaching the pronotum, widely separated, mesothorax trapezoidal, comparatively large (relative to the remainder of the mesosoma), propodeum conversely trapezoidal, propodeum with irregular and coarse reticulate sculpturing.

Metasoma slender, but the first metasomal segment relatively broad, nearly elongate oval, the second metasomal segment narrower and shorter than the first, but broader than others, conversely trapezoidal, the third, fourth and fifth metasomal segments very slender, tubular, the third longest segment of the metasoma, the sixth metasomal segment slightly broader than the preceding three segments, nearly fusiform, apex extraordinarily acute, as long as the first metasomal segment, ratio of lengths of metasomal segments is 1.0:0.8:1.2:0.8:0.6:1.0.

Forewing with only two tubular veins (C and R), R straight; pterostigma elongate and narrow, tapering to a point on anterior wing margin; cell r nearly triangular; 3r closed, narrow and long; 2r–rs arising slightly basad of pterostigmal midpoint, longer than the pterostigmal width; the first abscissa of Rs and the first abscissa of M slightly bent and slightly angled toward wing base vein, ratio of length of first abscissa of Rs and M nearly 2:1; Rs+M weak and nearly invisible; 1m –cu very short; shape of cell 1mcu between triangle and trapezoid (transition from triangle to trapezoid); Rs forming two branches, Rs1 and Rs2. Rs1 straight and reaching wing margin much before wing apex. Rs2 nebulous, long and tapering to point near the anterior wing margin, but not reaching it. M+Cu distinct and straight, M weak, subtle (may be due to preservation), straight and reaching the wing margin; Cu tapering to the wing margin and reaching wing margin, but nebulous near wing margin; 1cu–a slightly bent and shorter than 2cu–a, not reaching A; 2cu–a reaching A, and intersecting Cu in line with 1m –cu. A exceedingly weak and nebulous, bending posteriorly and reaching wing margin. Hind wing slight longer than half length of forewing, with C only ( Fig. 4 View FIGURE 4 ).

Trochanter, femur, tibia and basitarsus of left fore leg preserved. Protrochanter visible, but smaller than the metatrochanter, trapezoidal; profemur slightly club–shaped and slightly thicker than protibia, protibia nearly as long as the profemur, thin basally and gradually thickening towards the apex, probasitarsus quite long, as long as half protibia, but narrower than the protibia. Mid leg preserved incompletely. Hind leg trochanter extraordinarily large and oblong. Metafemur slightly club–shaped and slightly thicker than metatibia; metatibia preserved incompletely.

Measurements (mm). Body length 17.5; head length 1.1, width 1.5; antennae length 6.4, ratio of antenna length and body length is 0.4; mesosoma length 3.5, width 2.0; metasoma total length 12.9, lengths of metasomal segments are 2.4, 1.9, 2.8, 1.9, 1.4 and 2.5; length ratio of metasomal segments is 1.0:0.8:1.2:0.8:0.6:1.0; forewing length 6.1, width 2.1; hind wing length 3.2, width 0.8; profemur length 0.9, protibia 0.9; metatrochanter length 0.4, metafemur 1.6.

Remarks. Shoushida gen. nov. can be assigned to subfamily Pelecininae mainly because forewing venation with Rs1 reaching or nearly reaching margin of wing; Rs forming two branches, Rs1 and Rs2; and Rs2 long, female metasoma tubular.

The subfamily Pelecininae is extremely small, including only three species within one extant genus and six species within three extinct genera. Two out of the three extinct genera ( Protopelecinus and Henopelecinus ) were based only on male specimens, and the female is unknown. The family Pelecinidae presents sexual dimorphism in many characters, mainly in metasoma. It is difficult to place this new “female” specimen in an existing genus with only a “male” description. In addition, this new specimen has a very different and unique forewing venation. The venation is similar to that of Pelecinus , except for one obviously different character: Rs1 straight and extending to wing margin much before apex; whereas in Pelecinus Rs 1 visibly bent downwards anteriorly. This unique venational character also differentiates this new genus from the three extinct genera in subfamily Pelecininae , e. g. Pelecinopteron , Protopelecinus and Henopelecinus ( Engel, 2002; Zhang & Rasnitsyn, 2004; Engel & Grimaldi, 2006). Therefore, we erect a new genus and species.