Xanthopimpla crescendae, Klopfstein, 2022

Klopfstein, Seraina, 2022, High diversity of pimpline parasitoid wasps (Hymenoptera, Ichneumonidae, Pimplinae) from the lowermost Eocene Fur Formation (Denmark), Geodiversitas 44 (23), pp. 645-664 : 660-661

Xanthopimpla crescendae n. sp.

( Fig. 11 )

urn:lsid:zoobank.org:act:343B9824-38A4-45C6-8730-E0B51D695735

TYPE MATERIAL. — Holotype FUR-11214 (male?, part and counterpart; leg. E. Rettig), paratypes FUR-13065 (female), FUR-10918 (sex unknown).

ETYMOLOGY. — This wasp is dedicated to my dear friend Tabia Stoffel, nickname “Crescendo”, for her unwavering support over the years.

TYPE HORIZON AND LOCALITY. — Denmark, Jutland, Limfjord region, MorsØ Kommune , Klinten ved Klitgård (holotype); Svalklit (FUR- 13065). Skive Kommune, Østklinten (FUR-10918).Cement stone.

MATERIAL EXAMINED. — Tentatively identified as the same species: FUR-13068 , 16642 , 17232 , 17235 .

DIAGNOSIS. — Taxonomic placement: the areolet shape, outwardsbowed 2m-cu in the forewing, as well as the short and stout T1 and robust, protruding ovipositor clearly indicate Pimplinae . But most of all, there is clear evidence for placing this species in Xanthopimpla : narrow (twisted) mandibles (visible in holotype), yellow or orange ground colouration with paired, dark markings on several tergites, stout legs, extensive carination of the propodeum, hind wing with 1-Cu shorter than cu-a (nervellus broken above middle), large claws. Species diagnosis: this species stands out within the genus by its almost or entirely dark mesoscutum and broad light mark at the base of the pterostigma, a combination not seen in any extant nor in the three known fossil species of the genus. Xanthopimpla biamosa Khalaim, 2008 from the Oligocene of Biamo ( Russia) furthermore has much shorter and stouter hind femora and two lateral dark marks on tergite 1, instead of its base being dark. X. messelensis Spasojevic et al., 2018 from the mid Eocene deposit in Messel has a very narrow, triangular areolet and dark basal bands instead of clearly disconnected spots on tergites 2-3. And X. praeclara Spasojevic, Wedmann & Klopfstein, 2018 , also from Messel, can be distinguished by the entirely yellow tergite 2. Among the here-in described Fur fossil species, T. nigriscutum n. sp. is most similar to X. ciboisae n. sp., from which it can be distinguished by its dark mesoscutum, smaller size and more slender metasoma.

DESCRIPTION

Preservation

Holotype preserved in dorsal view, with head including most of one and a partial second antenna, most of mesosoma, one nearly complete but somewhat distorted and one longitudinally folded forewing, two partial hind wings, partial hind legs, and metasoma except for its tip. Metasoma especially well-preserved, including traces of microsculpture on the tergites. Paratype in dorsal view, head without antennae, most of mesosoma, partial fore wings, one nearly complete hind wing, metasoma except for its tip.

Body c. 7.8-9.3 (c. 7.8) mm. Yellow to orange, with dark brown head, antennae uniformly orange. Dark on entire mesoscutum except maybe two lateral patches, basal part of propodeum, wing veins except basal half of pterostigma, basal two thirds of T1, paired spots on T2 to T4, on T5-6 these spots combining into a basal dark stripe.

Head. In holotype turned upward to show from front, rather high with large compound eyes, these seemingly converging towards ventral (but this might be an artefact); with very narrow, darkened and bent mandibular tips than might indicate either a single tooth or strongly narrowed and twisted mandibles. Antennae incomplete, showing at least 23 clearly outlined flagellomeres (estimated: 26 in total), these in proximal half about twice as long as wide, after middle about 1.5 ×, and penultimate segments about as long as wide.

Mesosoma. Rather slender, in holotype distorted between mesoscutum and propodeum. Mesoscutum about as long as wide, with strongly converging but not meeting notauli. Propodeum with carination partially preserved (holotype), showing at least basal transverse, and lateral parts of apical transverse, and part of the median longitudinal carinae.Fore wing 5.5-6.3 (5.5) mm; areolet closed, quadrate, with uneven sides, 4-M very short, 2r-m a bit shorter than 3r-m; 2m-cu not well preserved in holotype but clearly bowing outwards in paratype; pterostigma 3.7-3.9 (3.7) × longer than wide; 1cu-a meeting M + Cu opposite 1-M; 3-Cu a bit longer than 2cu-a; radial cell 3.2-3.3 × (3.3) longer than wide.Hind wing with 1-Rs about 1.8 × (paratype) longer than 1rs-m, 1-Cu 0.5-0.7 × (0.5) as long as cu-a.Hind leg very short and stout, femur about 2.5 × longer than wide. Tarsal claw discernible, rather large.

Metasoma. With T1 about 1.1 × longer than wide, with strong median longitudinal carina converging on basal half, parallel posteriorly; T2 0.6 × as long as wide, basally with oblique grooves cutting off anterolateral corners, behind these with slowly converging grooves that cut off a roundish-trapezoid raised part medially bearing two confluent dark patches, this part with strong punctures visible. T3 with paired dark patches on basal half and pre-apical transverse groove indicated. T4-T7 with paired dark marks weakly indicated. Ovipositor not preserved.

Figures

FIG. 11. — Holotype of Xanthopimpla crescendae n. sp. (FUR-11214), photograph (A) with details and interpretative drawing (B), where dotted lines represent uncertain and/or interpolated interpretations. Scale bar: 1 mm.