Proapocritus bialatus Li, Shih and Ren, 2014

Li, LongFeng & Shih, ChungKun, 2014, Two new fossil wasps (Insecta: Hymenoptera: Apocrita) from northeastern China, Journal of Natural History 49 (13), pp. 829-840 : 834-837

Proapocritus bialatus Li, Shih and Ren sp. nov.

( Figures 3 , 4 )

Etymology

The specific epithet is derived from the Latin word bialatus (a pair of wings), indicating the well-preserved and out-stretched wings.

Material

Holotype female CNU-HYM-NN-2012040 .

Locality and horizon

Jiulongshan Formation, Daohugou Village, Shantou Township, Ningcheng County, Inner Mongolia, China; Middle Jurassic.

Diagnosis

Antenna slim, with more than 25 segments. Forewing with cu-a slightly postfurcal, 1r-rs vein reduced near R and pterostigma, 2r-m, 3r-m slightly bent (not vertical); 2mcu wavy curved; hind wing with 1-Rs originating not basad of M + Cu fork, 1-M and cu-a nearly parallel. First metasomal segment nearly trapezoid.

Description

Female wasp in dorsal view; left and right wings well preserved with main veins clearly discernible ( Figure 3A, B ).

Body 15.8 mm long including the antennae and ovipositor (body 9.6 mm long excluding the antennae and ovipositor); the head transversely broad, about 0.9 mm long and 1.8 mm wide; antenna thin and well preserved, with 25 antennomeres and about 5.4 mm long, pedicel short and slightly narrower than distal part of the scape, flagellomeres equal in length and width; mesosoma long and slender, about 3.1 mm long and 1.9 mm wide; pronotum, mesonotum, mesoscutellum, metanotum, metascutellum and propodeum discernible ( Figure 3A, B ); the mesonotum with notauli nearly V-shaped and reaching transscutal suture; mesoscutellum slightly wider and longer than metanotum; propodeum longer than metanotum; metasoma 5.5 mm long excluding the ovipositor, with six segments visible, the first metasomal segment nearly trapezoid, apical part about 1.5 times as wide as basal part. Ovipositor 5.2 mm long with sheaths; legs partially preserved and the hind legs longer and wider than the forelegs and mid legs.

Forewing 6.7 mm long and 2.1 mm wide as preserved, with pterostigma long and acuminate, issuing 2r-rs at its mid-length ( Figure 3A, B ); the first abscissa of Rs (1- Rs, 0.3 mm long) subvertical to R and slightly shorter than that of M (1-M, 0.4 mm long); vein 1r-rs present but reduced near R and pterostigma, and the distance of 1r-rs to Rs base longer than that to 2r-rs base; vein 2r-rs slightly longer than the width of pterostigma and nearly as long as the maximal width of cell 2rm, and about half the length of 2rm, and subparallel to 1r-rs and 1-Rs; cell 1mcu nearly parallelogrammic, about 2.5 times as long as wide; vein 1m-cu (0.4 mm long) meeting 2rm slightly beyond Rs + M forking and slightly shorter than cu-a (0.5 mm long); vein cu-a slightly postfurcal, parallel to a 1 -a 2 and 1.6 times as long as a 1 -a 2; vein 2m-cu bending and 1.5 times as long as 1m-cu; vein 2A completely preserved.

Hind wing 3.6 mm long and 1.5 mm wide as preserved, distinguishable with 1-Rs origin at the same level of M + Cu forking; cell r closed; vein r-m straight and 0.6 times as long as 1-Rs; the first abscissa of M (1-M) slightly arched and about three times as long as r-m; vein cu-a long and strongly oblique, meeting Cu beyond M + Cu forking; vein A present, free M and Cu long.

Remarks and comparison

The genus Proapocritus, 1975 was erected by a hymenopteran forewing from the Early or Middle Jurassic Kyrgyzstan, and tentatively placed in Karatavitidae ( Karatavitidae was considered to be the most primitive apocritans). Proapocritus was considered to almost completely cover the hiatus between Karatavites of Symphyta and Ephialtitidae of Apocrita ( Rasnitsyn 1975). Until 2010, Rasnitsyn and Zhang have reported six new species ( Proapocritus densipediculus , Proapocritus sculptus , Proapocritus formosus , Proapocritus atropus , Proapocritus longantennatus , Proapocritus elegans ) of this genus, all specimens from the Middle Jurassic Jiulongshan Formation at Daohugou Village of China. New and complete material not only provides new characters of this group but also broadens the diversity of Ephialtitidae .

Proapocritus bialatus sp. nov. is assigned to to Proapocritus Rasnitsyn, 1975 because of the following characters: wings with complete venation, forewing with 1- Rs directed slightly posterodistally; 1r-rs, 2r-m, 3r-m, 2m-cu, 2A and a 1 -a 2 present; hind wing with enclosed cell r; Rs originating not basad of M + Cu fork and so on. This new species differs from other species (except Proapocritus densipediculus ) of the genus Proapocritus in the forewing with cu-a slightly postfurcal (versus other species of the genus with cu-a intersitial); differs from Proapocritus densipediculus in forewing with 2r-m, 3r-m slightly bend and 2m-cu wavy curved and the first metasomal segment nearly trapezoid (versus Proapocritus densipediculus with 2r-m, 3r-m vertical while 2m-cu not preserved, and the first metasomal segment as wide as propodeal foramen, subcylindrical).

Figures

Figure 3. Proapocritus bialatus sp. nov., photographs of holotype (CNU-HYM-NN-2012040). (A) Body with wings with alcohol; (B) body with wings without alcohol. Scale bars = 1 mm.

Figure 4. Proapocritus bialatus sp. nov., line drawings of holotype. (A) Body with wings; (B) left wings; (C) right wings. Scale bars = 1 mm.