Prosyntexis antennata Li, Shih & T. Gao, 2023

LI, XIAO-QIN, RASNITSYN, ALEXANDR P., GAO, JIA, ZHANG, YAN-JIE, SHIH, CHUNG-KUN, REN, DONG, ZHAO, YUN-YUN & GAO, TAI-PING, 2023, New taxa of Sepulcidae (Hymenoptera) from mid-Cretaceous Kachin amber, Palaeoentomology 6 (2), pp. 133-145 : 140-142

Prosyntexis antennata Li, Shih & T. Gao sp. nov.

( Figs 8 , 9 )

Type material. Holotype: CNU-HYM-MA2015107, a male specimen. Most of body preserved except left antenna broken and with apex lost, and left forewing broken.

Etymology. The name antennata is derived from the Latin word antennatus referring to the long antennae.

Diagnosis. The new species is unique within Prosyntexis in having cu-a behind the fork of M+Cu in the hind wing (hind wings not preserved or very incomplete in P. gouleti , P. gobiensis , P. montsecensis and P. aristovi ). It also differs from other species, except for P. aristovi , in having a short and thin Sc in the forewing; and distinguished from P. aristovi by short 3-M (3r-m and 2m-cu approaching).

Locality and horizon. Hukawng Valley, Kachin State, northern Myanmar; lowermost Cenomanian, mid-Cretaceous.

Description. Body about 6.51 mm long in lateral view, antenna 8.31 mm long in lateral view; forewing about 5.89 mm in length, maximum width 2.56 mm; hind wing about 4.31 mm in length, maximum width 1.82 mm ( Fig. 8A, B ).

Head 0.60 mm long and 0.68 mm height in lateral view, slightly small and subquadrate. Compound eyes slightly large and preserved in a shrunken state. In lateral view maxillary palpus with six palpomeres, palpomere I short and thick; palpomere II 0.33 mm long and swelled apically; palpomere III elongate and almost 0.71 mm long; palpomere IV 0.46 mm long; palpomere V 0.43 mm long and palpomere VI 0.44 mm. Labial palpus with two palpomeres with inflated last segment ( Fig. 9C ). Antenna elongate and filiform with 16 segments; scape 0.30 mm long, maximum width 0.12 mm; pedicel 0.42 mm long, maximum width 0.16 mm, slightly swollen apically; flagellomere I longer than scape and pedicel, 0.81 mm long, 0.15 mm wide, flagellomere II 0.74 mm long, 0.12 mm wide, as wide as individual widths of remaining flagellomeres ( Fig. 9A ).

Thorax with membranous medial depression in the mesonotum bordered laterally by strong striate surfaces ( Fig. 9D ). Legs slender, profemur slightly longer than protibia; metafemur length 1.21 mm, metatibia 1.55 mm long, maximum width 0.22 mm. Single protibial spur, cleft apically ( Fig. 9F ); mesotibia with two apical spurs ( Fig. 9G ); metatibia with two apical spurs (smaller spur thick and less than half length of larger spur) ( Fig. 9H ). Tarsi pentamerous, basitarsomere long but shorter than remaining tarsomeres combined; tarsomere V not elongate; pretarsal claws short, with curved apices and additional inner teeth ( Fig. 9I ).

Forewing ( Fig. 8C ) with C strongly thickened; costal space obviously narrow, slightly enlarged at middle; Sc short and thin, appearing like a crossvein before origin of Rs; 1-Rs slanted toward wing apex and twice as long as 1-M; pterostigma long and broad, oblong and 3.5× as long as wide with center translucent; M+Cu bent basally. 2-Rs+M especially short; junction of 2-Rs, 2-Rs+M and 2+3-M very weak; 1r-rs connected to pterostigma at its base and slightly shorter than section of Rs between 1r-rs and 2r-rs; 2r-rs issuing from 1/4 of pterostigma and at two-fifth of 2+3rm length; 2rs-m absent; 3-M short and 0.3× as long as 2m-cu. Cell 1mcu subquadrate, about 2.4× as long as wide; cell 2mcu hexagonal, about 2× as long as wide. 2A+3A wavy medially. Aberrant vein extending from 4-Cu near 2m-cu of left forewing, towards posterior margin of the wing ( Fig. 8C ).

Hind wing ( Fig. 8C ) with basal and distal hamuli present (no intermediate ones found); cell r close; Sc+R present; 1-Rs about 1.08 mm in length, nearly 1.7× as long as 1-M; 1rs-m about 0.30 mm in length, proclival and short; 1-M bent; 2rs-m, 3rs-m and 1m-cu absent; terminal abscissa of Cu and cu-a well-developed; 1-Cu and cu-a straight, 1-Cu especially short and nearly 0.2× as long as cu-a in left hind wing; right hind wing lacking 1-Cu (cu-a coinciding with M+Cu fork).

Abdomen with nine distinguishable segments in lateral view. Male genitalia ( Fig. 9E ) narrow, with gonostyle slender and about 0.36 mm long; cercus about 0.24 mm long.

Figures

FIGURE 9. Photographs of Prosyntexis antennata sp. nov., holotype (specimen CNU-HYM-MA2015107) male. A, Photograph of habitus in right lateral view. B, Hamuli of right hind wing. C, Maxillary palpus and labial palpus in ventral to the left view. D, Mesonotum, with arrows indicating transverse ridges. E, Male genitalia in left lateral view. F, Left protibial spur. G, Left mesotibial spurs. H, Left metatibial spurs. Abbreviations: Ce, cercus; GC, gonocoxa; GS, gonostyle; Lp, Labial palpus; Mp1–6, maxillary palpus I–VI. I, Left mesotarsal pretarsal claw. Scale bars: 1 mm for A; 0.5 mm for B, D, E; 0.2 mm for C; 0.1 mm for F–I.

FIGURE8. One photograph andtwoline drawingsof Prosyntexis antennata sp. nov., holotype(specimen CNU-HYM-MA2015107) male. A, Habitus in left lateral view. B, Line drawing in left lateral view. C, Line drawing of the left forewing and left hind wing. Scale bars: 1 mm.