Cresogmus grimaldii Rasnitsyn & Kolyada, 2022

RASNITSYN, ALEXANDR P., KOLYADA, VIKTOR A., VORONTSOV, DMITRY D. & ÖHM-KÜHNLE, CHRISTOPH, 2022, The first Proctotrupidae (Hymenoptera) in Burmese amber, with description of a new genus and species, Palaeoentomology 5 (5), pp. 445-451 : 449-450

Cresogmus grimaldii Rasnitsyn & Kolyada sp. nov.

urn:lsid:zoobank.org:act:6A725B80-1483-4107-88BF-45E9BD135927

Holotype. Female, PIN no. 5620/144, complete but somewhat distorted (laterally compressed and otherwise deformed) insects with integuments degraded, surface sculpture modified and not well visible.

Etymology. The species is named to honor David Grimaldi.

Diagnosis. As for genus.

Locality and horizon. Hukawng Valley, Kachin State, Myanmar; mid-Cretaceous.

Description. General color dark fuscous, with antennae, knees, tibiae, tarsi and ovipositor sheaths less dark. Surface sculpture distorted and difficult to reliably describe.

Head form somewhat distorted, as preserved longer than high and wide, with eyes rather small, subcircular, weakly convex, in lateral view distant from hind head margin for almost eye length, with two hind ocelli visible distant from all eyes, antennal bases, hind head margin and from each other. Occipital carina low but distinct along all hind head margin visible. Antennal attachments distinctly apart from each other, margined with small ridges medioventrally, distant from both eyes and clypeus. Clypeus rectangular, slightly wider than long, with fore and, partially, lateral sides margined, with fore margin slightly emarginate. Antenna with scape longer than other antennomeres, pedicel hardly visible, flagellum apparently widened apically (unless due to compression); length ratio of antennomeres (very tentatively because of deformation, possibly uneven, and improper position in amber) 1:0.2:0.7:0.7:0.7:0.7:0.7:0.7:0.65:0.55:0.55:0.8. Labrum, if correctly identified, long, wide, with narrow base. Mandible of usual proctotrupine form (short sicklelike with sharp apex). Maxillary palp with five long, narrow segments visible.

Pronotum moderately long medially on fore declivity of mesosoma, with spiracle at its surface near to its upper and hind margins, with impressed posterior area with vertical row of several (apparently 5) tubercles and imperfectly visible subvertical crease outlining possible rudiment of netrion (= postspiracular sclerite sensu Rasnitsyn, 1980: 86 and Shcherbakov, 1980; = interpleurite, prepectus sensu Gibson, 1993). Notauli percurrent, wide, with no distinct signs of being transcostate; scutellum long, with prescutellar fossa(e) not well visible; metanotum long, weakly convex in side view, with slit (hidden metapostnotum) delimiting it with propodeum; propodeum evenly, gently arching down to metasomal base, extending behind hind coxal attachment for near half hind coxa length. Propleura not well visible, mesopleuron with transverse groove apparently distinct in hind half and fan-like widened before, apparently with no other gross sculpture; metapleuron apparently longitudinally costate in fore half, propodeal sculpture not clear; distance of mesosomal articulation of hind coxa to that of mid coxa three times that to metasomal articulation. Legs apparently thin (deformed by compression), with tibiae apparently subequal or slightly longer than respective femora, and tarsi apparently so in respect to their tibiae (varying at figures because of deformation and improper position in amber); trochantelli delimited, tibial spurs 1:2:2, each pair of subequal length, basitarsus subequal to three mid tarsomeres combined, tarsomeres 3 and 4 of similar lengths, claw thin, simple, gently curved, arolium slightly longer than claw; fore tibial spur evenly slightly bent, bifid apically; fore basitarsus slightly excised almost over all its length, with row of 13 erect setae of subequal length along excision.

Forewings somewhat deformed (particularly left one), with only C, R, 2r-rs and RS behind and shortly before 2r-rs tubular, with only cells c and 3r closed, pterostigma semicircular, with 2r-rs slightly behind its middle, 2r-rs about twice as long as wide, RS before 2r-rs about as long as 2r-rs as tubular, further continuing as nebulous for similar distance; cell 3r as long as pterostigma (0.75× so along wing margin), C extending shortly behind 3r apex. Hind wing with only C+R tubular for distance equal to length of pterostigma and with distinct but colorless section of anal vein near wing midlength, with three hamuli, one (basal) gently bent and two hook-like.

Metasoma long, with petiole short but distinct, syntergum taking half of its visible length, following three terga (one elongate, another almost as long as high, third very short in lateral view), all lacking visible sculpture, spiracles, traces of fusion and other important features; ovipositor sheaths evenly wide except apically, strongly, evenly bent down except in basal third, widely rounded apically. Ovipositor extending subapically (a deformation occurring sometimes with encasement in resin as well as with alcohol storage: normally ovipositor protrudes only between apices of sheaths; Townes & Townes, 1981: 8), with apex very thin, sharp, bearing traces of oblique notch.

Measurements (in mm, tentative because of deformations). Body length (without antennae and ovipositor) 2.15, head length 0.36, antenna length ca. 1, mesosoma length 0.8, height 0.31, forewing length 1.2, width 0.57, fore femur length 0.3, tibia 0.32, tarsus 0.31, mid femur 0.35, tibia 0.31, tarsus 0.36, hind femur 0.31, tibia 0.44, tarsus 0.33, dorsal length of syntergum and visible free terga 0.61, 0.33, 0.11, 0.02, length of ovipositor sheath 0.23, width at midlength 0.05.