Orthosyntexis elegans J. Gao, Engel, Shih, & T. Gao, 2021

Gao, Jia, Engel, Michael S., Shih, Chungkun, Ren, Dong & Gao, Taiping, 2021, A new genus of anaxyelid wood wasps from the mid-Cretaceous and the phylogeny of Anaxyelidae (Hymenoptera), Journal of Hymenoptera Research 86, pp. 151-169 : 151

Orthosyntexis elegans J. Gao, Engel, Shih, & T. Gao sp. nov.

Figs 1 , 2 and 3

Etymology.

The specific epithet is derived from the Latin word Orthosyntexis elegans , meaning elegant.

Diagnosis.

Antennal scape length to width ratio slightly less than 3. Forewing 1Rs subvertical to R. Meso- and metafemur shorter than associated tibiae; mesotibial apical spurs elongate and distinctly narrowed apically.

Holotype.

Female, no. CNU-HYM-MA2015101 (Figs 1 - 3 ).

Type locality and horizon.

The amber specimen was collected from Kachin (Hukawng Valley) in northern Myanmar, and is dated at 98.79 ± 0.62 Mya ( Cruickshank and Ko 2003; Shi et al. 2012).

Description.

Body about 8.25 mm long in dorsal view, antenna 2.73 mm long in ventral view; forewing about 5.69 mm in length, maximum width 1.74 mm; hind wing about 4.57 mm in length.

Head moderately large, narrower than thorax. Head 1.85 mm wide and 1.23 mm long, nearly quadrate. Compound eyes large and hemispherical; mandible straight, orthogonal with apical margin vertical (parallel to mandibular base) and with lowest tooth not that elongate (Fig. 2C ); labial palpus with three palpomeres; maxillary palpus with at least five palpomeres; antenna with 16 flagellomeres, scape 0.40 mm long, maximum width 0.14 mm; pedicel 0.39 mm long, maximum width 0.12 mm; flagellomere I shorter than scape, 0.11 mm wide, 0.22 mm long, flagellomere II 0.10 mm wide, 0.19 mm long, as long as individual lengths of remaining flagellomeres (Fig. 2B ).

Thorax wide, width across tegulae 1.56 mm; pronotum short, having prominent anterior notch and hind margin, with median longitudinal furrow dorsally. Mesoscutum with median longitudinal sulcus and notauli strongly impressed; mesoscutellum tapering to acute apex; ratio of lengths of prescutum, median longitudinal sulcus between notauli, and mesoscuto-mesoscutellar sulcus and mesoscutellum 2.5/1/4.5, notauli terminating close to mesoscutellum (Fig. 1A ). Legs spindly, meso- and metafemora shorter than associated tibiae. Metafemur length 1.30 mm, metatibia thick subapically, length 1.65 mm. Protibia and metatibia with only one apical spur visible, mesotibia with two apical spurs (Fig. 3C, D and E ); all tarsomeres with stiff apical setae; basitarsi long but shorter than remaining tarsomeres combined; tarsomere V elongate but shorter than basitarsus; pretarsal claws long, with curved apices and each with a single preapical tooth.

Abdomen only slightly narrower than mesothorax; abdominal tergum I split medially. Segments I and II slightly longer than remaining abdominal segments; ovipositor length 1.86 mm, not protruding beyond abdominal tip, strongly serrated apically (Fig. 2D and 2E )

Forewing with dense microtrichia but no coloration pattern except slightly darkened costal area. C and R thick, costal area narrower than C and R widths. Pterostigma completely sclerotized; Sc absent; 1r-rs and 2rs-m absent; 2r-rs issuing from pterostigma at its basal 1/3; 1Rs short and subvertical to R (Fig. 3A ), about 0.6 × as long as 1M, meeting 1M at right angle. 2Rs+M distinct but short, 0.3 × as long as 1Rs+M. 2r-rs slightly proclival. 2+3M 1.1 × as long as 4M. Cell 1mcu pentagonal, about 1.9 × as long as wide; cell 2mcu hexagonal, about 1.3 × as long as wide. 2Cu 1.7 × as long as 1Cu. 1cu-a strongly reclival, nearly 0.7 × as long as 1Cu. 1m-cu nearly as long as 3Cu, 3Cu shorter than 4Cu. 2m-cu nearly 0.7 × as long as 4M and 1.2 × as long as 1m-cu.

Hind wing Sc absent. Cell r closed. 1Rs (about 0.28 mm in length) shorter than 1M (about 0.35 mm in length). 1rs-m (about 0.27 mm in length) reclival, nearly in line with 1M and as long as 1Rs. 1M straight; m-cu absent; 2M+Cu present (about 0.39 mm in length), free abscissa of Cu and cu-a (about 0.48 mm in length) developed, 1Cu and cu-a straight.

Figures

Figure 1. One photograph and two line drawings of Orthosyntexis elegans gen. et sp. nov., holotype (specimen CNU-HYM-MA 2015101) female A dorsal view as preserved B line drawing of dorsal view with forewings and hind wings artificially extended from body C line drawing of forewing and hind wing. Scale bars: 1 mm (A, C); 2 mm (B). Abbreviations: mms, mesoscuto-mesoscutellar sulcus; mls, median longitudinal sulcus; na, notaulus; psc 2, mesoprescutum; scl 2, mesoscutellum.

Figure 2. Photographs of Orthosyntexis elegans gen. et sp. nov. A habitus in ventral view B antenna in lateral view C mandible in ventral view D part of abdomen in lateral view E apical ovipositor in lateral view. Scale bars: 1 mm (A); 0.2 mm (B, C); 0.5 mm (D); 0.1 mm (E). Abbreviations: Fla 1 and Fla 2, flagellomeres I and II; Pe, pedicel; Sc, scape.

Figure 3. Photographs of Orthosyntexis elegans gen. et sp. nov. A part of left forewing B hind wing hamuli (white arrows) C right protibial spur D right mesotibial spurs E left metatibial spur. Scale bars: 0.5 mm (A); 0.1 mm (B-E).