Eutomostethus karimae, NEL & NIU & WEI, 2022

NEL, ANDRÉ, NIU, GENG-YUN & WEI, MEI-CAI, 2022, First fossil representative of the sawfly subfamily Blennocampinae (Hymenoptera: Tenthredinidae), Palaeoentomology 5 (2), pp. 99-104 : 100

Eutomostethus karimae sp. nov.

( Fig. 1 ) urn:lsid:zoobank.org:act:57F61C51-8184-4B93-A2C4-568EDE6C2A29

Material. Holotype UCM-61412 (a nearly complete wasp with legs missing, together with a Hemiptera Cixiidae , four Diptera (one Syrphidae and three Sciaroidea), and an enigmatic large insect (maybe an Orthoptera), housed in the Invertebrate Paleontology collection, University of Colorado Museum of Natural History (Boulder, Colorado, USA).

Etymology. Named after Dr. Talia Karim, for her kind and efficient help. The species epithet is to be treated as a noun in the genitive case.

Diagnosis. Small wasp, with forewing ca. 4.7 mm long, body ca. 5.3 mm long, wings hyaline, pterostigma dark brown anteriorly and more hyaline posteriorly.

Locality and horizon. Eocene, Green River Formation, Anvil Point Labandeira, Garfield, Colorado, USA.

Description. Body length ca. 5.3 mm. Color. Body brown with darker head; compound eyes dark brown; wings hyaline, pterostigma dark brown anteriorly and more hyaline posteriorly. Head poorly preserved, 0.8 mm long, 1.1 mm wide; compound eyes ca. 0.5 mm apart; mouthparts not preserved, except maybe labrum; short and stout antenna, antenna 1.7 × head width; no antennal organ, seven antennal flagellomeres preserved but antennae not complete, scape and pedicel missing; third antennomere slightly longer than fourth; antennomeres 5, 6 and 7 of same length. Thorax ca. 1.7 mm long, 1.6 mm wide, apparently smooth; a flat epicnemium. Abdomen without visible surface sculpture, 2.8 mm long, 1.7 mm wide; ovipositor short and broad, 0.5 mm long. Legs not preserved.Forewing not complete, with apices lacking, ca. 4.7 mm long, 1.8 mm wide; vein R not deviated between junctions of M and Sc; pterostigma 0.7 mm long, 0.3 mm wide; first free sector of Rs between cells 1R1 and Rs; cell 1R1 0.4 mm long, cell 1Rs 0.6 mm long; cell 2Rs 0.8 mm long; veins M and 1m-cu parallel; nervulus (1cu- a) situated at middle of cell 1M; crossvein of anal cell lacking; vein 2A strongly curved apically and touching 1A; vein 3A not visible. Hind wing 3.3 mm long, 1.2 mm wide; cell Rs opened; cell M closed; crossvein m-cu present; ratio of petiole to cu-a = 1.1.

Figures

FIGURE 1. Eutomostethus karimae sp. nov., holotype UCM-61412. A, Photograph of habitus. B, Detailed photograph of body. C, Detailed photograph of wing. Scale bars = 1 mm.