Electroembia olmii Anisyutkin et Perkovsky, 2024

Anisyutkin, Leonid N., Legalov, Andrei A. & Perkovsky, Evgeny E., 2024, New species and new record of embiids (Insecta: Embiodea) from upper Eocene of Europa, Ecologica Montenegrina 79, pp. 16-28 : 17-21

Electroembia olmii Anisyutkin et Perkovsky , sp. n.

https://zoobank.org/ urn:lsid:zoobank.org:act:55595047-3DC4-4996-A09A-3FBD37BE1840

( Figs 1 – 8 )

Type material. Male, GPIH no. 5051 (from CCGG no. 11274), Yantarnyj, Baltic amber, Priabonian. Syninclusions: 2 Diptera (Brachycera, Sciaridae ), Hymenoptera (Diapriidae) , stellate hairs.

Description of inclusion. Amber piece ( Fig. 1 ) of flat elongate- oval shape, mostly transparent, approximately 47 x 30 x 9 mm; weight 6.19 g after primary processing; includes the holotype of the new species, two specimens of small Diptera and one specimen of Hymenoptera .

The holotype from above ( Fig. 2 ) is horizontal but slightly inclined to the left, so that the head, thorax and abdomen are visible at angle, right forewing is set back at right angles to the body, the left forewing and the right hindwing are sharply curved upward at the distal part. The holotype from below ( Fig. 3 ) is difficult to distinguish due to its oblique position, white coating and proximity to the edge of the inclusion.

Description. General color, as far as can be judged from the inclusion, dark brown, probably blackish, fore- and hindwings with longitudinal white stripes ( Fig. 2 ). Surfaces, as far as can be judged from the inclusion, smooth; surfaces of head appear finely shagreen (perhaps this is the effect of preservation of inclusion). Pubescence well developed on antennae, legs, cerci and, in lesser degree, on abdomen; lower side of tarsi with dense brush of chaetae. Head large and elongated, eyes large ( Figs 2, 3 , 4 ), anterior angles of submentum seems to be protruded anteriorly. Antennae with 14 segments; scapus large and broad, pedicellum small, slightly longer than wide, 3rd segment longer, about twice as long as pedicellum, 4th slightly shorter than 3rd, remaining segments gradually lengthen towards the apex; 1st – 3rd segments more or less cylindrical, remaining ones maximally expanded at the middle (3rd) or at the distal end 4th and succeeding segments ( Fig. 4 ). Pronotum longer than wide; anterolateral angles rounded; lateral margins sinuate, posterior margin nearly straight; division into pro- and metazone distinct; median groove absent ( Figs 2 , 4 ). Fore and hind wings of similar structure ( Figs 2, 3 , 5, 6 ), but hind wing slightly smaller, with more simple venation. Forewings ( Fig. 5 ) with Sc simple, shorter than half of forewing length, not reaching anterior wing margin; RA (= R sensu Engel and Grimaldi 2006; Cui et al. 2020) strong, connected with anterior wing margin; two crossveins ra-rs present; RS and MA forked in proximal half of wing, with two crossveins; RS simple; MA twice dichotomously branched (distal fork more expressed in left forewing); MP forked at wing margin; CuA connected with CuP; CuA simple and short, not reaching posterior wing margin; CuP strong, simple and short, not reach to distal half of wing; A short and simple. Hind wings ( Fig. 6 ): RS and MA simple, forked in distal half of wing; MP simple; CuA simple and long, reach to distal half of wing; CuP strong, simple and short, not reach to distal half of wing; A short and weak. Fore probasitarsus (1st tarsal segment of fore leg) ovalshaped, about two times long as wide (about 0.6 mm x 0.3 mm); 2nd and 3rd tarsal segments of about equal length (about 0.15 mm); 2nd segment about as long as wide, 3rd segment thin. Fore femora moderately widened. Left mid leg absent, right – indiscernible on inclusion. Hind femora strongly widened; hind tibia widened as well, with maximal width at apex; hind probasitarsus (1st tarsal segment) robust ( Fig. 7 ), about 2.3 times longer than high, with two large weakly protruded and nearly contiguous pulvillae; 2nd segment short, with protruded pulvilla; 3rd segment elongated, about as long as than probasitarsus, length of tarsal segments about 0.4, 0.15, 0.4 mm. All claws simple and symmetrical, arolia absent. Structures of abdominal apex generally similar to those of E. antiqua (compare Fig. 8 and Fig. 2 in Ross 1956 and Fig. 1 in Ross 1966). Terminalia strongly asymmetrical ( Fig. 8 ); Xth abdominal tergum deeply divided into hemitergites; left hemitergite (10L) smaller, as compared with right one, posteriorly produced in elongated apically sharpened process (10LP); right hemitergite (10R) large, distinctly longer than wide, posteriorly attenuated, with long thorn-like apical process (10RP); median flap (MF) round and membranous. Left cercus two-segmented; proximal segment with large subtriangular outgrowth on inner side, microspicules indiscernible; distal cercus cylindrical. Right cercus consists of two cylindrical segments, proximal segment slightly wider. IX sternite (hypandrium) indiscernible on inclusion.

Measurements (mm). Length of head 1.7; length of pronotum 0.8; length of fore femur 0.8; length of fore wing 5.6; width of fore wing 1.7; length of hind wing 5.4; width of hind wing 1.5; length of hind femur 1.2; length of hind tibia 1.1. All measurements approximate due to inclusion distortion and specimen deformation.

Comparison. The new species is similar to E. antiqua , but readily differs from it in presence of fore and hind wings. Additionally, E. olmii sp. n. differs from E. antiqua in larger eyes (compare Fig. 4 and Fig. 2 in Ross 1956), robust hind probasitarsus ( Fig. 7 ) (not elongated as in E. antiqua – Fig. 2 in Ross 1956), with two large weakly protruded and nearly contiguous pulvillae ( Fig. 7 ) (contrary to two small and distinctly separated pulvillae in E. antiqua – Fig. 2 in Ross 1956), longer thorn-like apical process of right hemitergite ( Fig. 8 ) and shape of proximal segment of left cercus (subterminal projection of this segment shifted to segment apex).

Etymology. The new species is named in honour of our late friend Massimo Olmi (1942-2024) world authority on Dryinidae , Embolemidae and Sclerogibbidae .

Distribution. Baltic amber, Priabonian.

Note. Intraspecific polymorphism in the structure of the wings is known for webspinners ( Ross 2000), but differences in the structure of the hind probasitarsi and abdominal apex show that E. olmii sp. nov. and E. antiqua are not conspecific.

Figures

Figures 1–3. Electroembia olmii Anisyutkin et Perkovsky, sp. n. 1 – General view of inclusion; 2, 3 – webspinner from above (2) and below (3). Scale bar for 1 = 10 mm, 2, 3 – out of scale.

Figures 4–8. Electroembia olmii Anisyutkin et Perkovsky, sp. nov. 4 – Head and pronotum, from above and slightly side (right); 5, 6 – Fore (5) and hind (6) wings from above, hind wing reconstructed; 7 – Left hind tarsus; 8 – Abdominal apex, from above and slightly side (right). Scale bar 1 mm: A = 4, B = 5, 6, C = 7, 8.