Sakhalinencyrtus leleji Simutnik, gen. et, 2021

Simutnik, Serguei A., Perkovsky, Evgeny E. & Vasilenko, Dmitry V., 2021, Sakhalinencyrtus leleji Simutnik gen. et sp. nov. of earliest Encyrtidae (Hymenoptera, Chalcidoidea) from Sakhalinian amber, Journal of Hymenoptera Research 84, pp. 361-372 : 361

Sakhalinencyrtus leleji Simutnik, gen. et sp. nov.

Figs 1 , 2A, D-F , 3 , 4A-C

Material.

Holotype, PIN 3387/128, 1♂, Sakhalin Island , village Starodubskoe ; Sakhalinian amber, middle Eocene. The inclusion is located close to the surface in a polished piece of amber in a shape of a parallelepiped (ca. 4 × 2.5 × 2 mm (Fig. 2A )). All body parts are preserved.

Syninclusions.

An undescribed female of Mymaridae (Fig. 2A-C ).

Etymology.

The species is named after Prof. Arkady Stepanovich Lelej, a world-class expert on Hymenoptera .

Description of male.

Body length, 0.9 mm. Habitus as in Figs 1A, B , 4C . Color. Head, mesosoma and metasoma brownish black; antennae, tegula, legs and veins of forewings brown; apices of femora lighter; wings hyaline. Mesoscutum and scutellum with reticulate sculpture (Fig. 3A ). Head hypognathous, slightly wider than thorax; vertex above upper level of eyes (Fig. 2D-F ); eyes small, almost circular, height of eye slightly less than length of malar space; form of scrobal depression unclear because face in holotype deformed (Fig. 2E ); toruli located midway between level of lower margin of eyes and mouth margin; face without a high interantennal prominence. Funicle 6-segmented; scape slightly extended and flattened, approximately 4 times as long as broad; pedicel conic, width of its apex slightly less than length, 1.5 times shorter than first two funicular segments; flagellum slightly flattened, not widen towards apex; all segments of funicle almost square and equal to each other; clava not segmented, not wider than last funicular segment, with oblique truncation extending along entire ventral surface and without sutures, equal in length to three previous funicular segments; flagellum with short and rare setae, lengths of which equal to half width of funicular segments (Fig. 2D ); longitudinal multiporous plate sensilla not visible on segments of funicle and clava; mandibles not visible. Mesosoma longer than metasoma, not flattened; pronotum short; mesoscutum flat, as long as slightly convex scutellum (Fig. 4C ); longer setae at apex of scutellum not visible; notauli not visible; axillae medially touching each other (Fig. 3A ); forewing hyaline; linea calva clearly defined, without filum spinosum, but with a well-developed row of long setae on its basal margin; parastigma widened, hyaline break (unpigmented area) of parastigma present (Fig. 3B, C ); venation of fore and hind wings in Fig. 3B, C ; stigmal vein with long narrow uncus, and with uncal sensilla; setae of marginal fringe short; procoxa large (Fig. 2D ); tarsi 5-segmented; protibia with long, curved spur (Fig. 2D ); spur of mesotibia thick, and slightly longer than mesobasitarsus (Fig. 1A, B ). Metasoma. Mt2-7 transverse; location of cerci in Fig. 4A, B ; Mt8 U-like, Mt9 V-like (Fig. 4A ); apical sternum (hypopygium) almost reaches apex of metasoma; genitalia (Fig. 4B ) hyaline, with a long phallobase and short aedeagus (excluding apodemes), without visible digiti.

Measurements are very inaccurate due to optical effects in amber: Head height 0.252, width 0.35; length 0.112; eye height 0.126, length 0.112; minimum distance between eyes 0.168; POL 0.07, OOL 0.028, distance between toruli 0.056, between torulus and eye 0.042; pedicel 0.056 × 0.035; flagellum 0.406; clava 0.126 × 0.042. Mesosoma. Length 0.426; forewing 0.7 × 0.42, marginal vein 0.07, postmarginal 0.126, stigmal vein with uncus 0.112; procoxal length 0.084; mesobasitarsus 0.07; mesotibial spur 0.077. Metasoma length 0.28, width 0.28; phallobase 0.126, aedeagus (excluding apodemes) 0.056.

Female unknown.

Conclusions.

The Encyrtidae from Sakhalinian amber are characterized by a unique position of cerci and forewing venation and represent the basal group of Encyrtidae . But, since so far they are represented by only one poorly preserved female and four males, the determination of their suprageneric relationships without studying female paratergites, seems to be premature.

Comparative morphological analysis of the representatives of middle and late Eocene fossil faunas ( Simutnik 2020 and the present publication) confirms that the Sakhalinian amber is much older than the Baltic, Rovno and Danish European ambers are.

Figures

Figure 1. Sakhalinencyrtus leleji gen. et sp. nov., holotype female A body, dorsal B body, ventral.

Figure 2. A Piece of Sakhalinian amber containing inclusions B, C syninclusion of Mymaridae, female B dorso-lateral C ventral D-F S. leleji gen. et sp. nov., holotype female: D antennae, head, mesosoma, ventral E antennae, head, frontal F antennae, head, and anterior part of metasoma, dorso-lateral.

Figure 3. S. leleji gen. et sp. nov., holotype female A head and mesosoma, dorsal B venation of fore and hind wings, dorsal C venation of fore and hind wings, metasoma and part of genitalia, ventral, cs- covering setae.

Figure 4. A-C S. leleji gen. et sp. nov., holotype female A apex of metasoma with cercus arrowed, dorso-lateral B apex of metasoma with cercus arrowed and genitalia, dorsal C habitus, lateral D Eucoccidophagus sp., venation of fore and hind wings.