Aspidopleura baltica Gibson, 2009

Gibson, Gary, 2009, Description of three new genera and four new species of Neanastatinae (Hymenoptera, Eupelmidae) from Baltic amber, with discussion of their relationships to extant taxa, ZooKeys 20 (20), pp. 175-214 : 195-199

Aspidopleura baltica Gibson , sp. n.

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Figs 45–56

Etymology. The generic name is formed from the Greek words aspido, meaning “shield” and pleuro, meaning “side”, in reference to its shield-like acropleuron. The species name is in reference to the amber origin.

Type material. Holotype (Fig. 45): ♀, AMNH, labelled “AMNH-JWJ-409” / “ HOLOTYPE Aspidopleura baltica Gibson ”. The holotype female is in a flat, spatulate piece of Baltic amber about 24 × 18 × 4 mm. The specimen is entire, but not visible from direct dorsal view and most of the right side is not visible because of an internal plane of irregularities (the right middle leg extends through the plane of irregularities) and with a crack extending from near the apex of gaster obscuring syntergal structure.

Paratype (Fig. 46): ♀, AMNH-JWJ-410. The paratype female is in a flat, triangular piece of Baltic amber about 19 × 14 × 6 mm. The specimen is entire, but its structure is partly obscured by pits in the surface of the amber block, a white milky substance around the specimen, and other internal artifacts.

Description. Length = 4.2 mm, including ovipositor. Body uniformly dark brown. Head in frontolateral view (Fig. 48) with convex interantennal region separating ventrally distinct scrobes, dorsally continuous scrobal depression shallowed dorsally and smoothly merged with frons below ocelli; parascrobal region incurved slightly and almost carinately margined from beside torulus to level about equal with dorsal angle of interantennal region; torulus with dorsal margin about in line with lower ocular margin (Fig. 48) and distance between ventral margin and oral margin about equal to its height; face uniformly coriaceous and setose except scrobes bare; clypeus with apical margin straight transverse. Head in dorsal view with vertex and temple rounded into occiput (Figs 47, 49); distinctly transverse, but relative dimensions not measurable; maximum diameter of ovoid posterior ocellus about 3× OOL and about 0.75× LOL (POL ratio not measurable accurately); occiput without occipital carina. Eye at least superficially bare (Figs 46–48). Mandible with small ventral tooth and slightly concave dorsal truncation (Fig. 48), tooth segregated from dorsal truncation by groove extending toward mandibular base. Antenna (Figs 47, 48) 13-segmented, scape foreshortened but ratio of segments from pedicel = 2.0: 1.2: 1.6: 1.6: 1.5: 1.4: 1.2: 1.2: 1.1: 2.1; scape (Fig. 47) elongate-rectangular, inner surface flat and outer surface dorsally convex and ventrally thin, flange-like; funicle with 8 segments, fu 1 (Fig. 47: fu 1) almost twice as long as wide and all segments except apical segment longer than wide and increased slightly in width apically; clava compact 3-segmented with sutures strongly oblique in lateral view (Fig. 47, upper antenna) so in ventral view (Fig. 48) two basal segments very short and with micropilose sensory region on terminal segment forming ventral channel if collapsed (Fig. 48: mps). Pronotum in dorsal view about one-third length of mesoscutum (Fig. 49: no 1, anterior portion of pronotum concealed by head), setose, with surface sloping from posterior margin; in lateral view (Fig. 51: no 1) almost vertical with dorsal half

Figures 45–50. Aspidopleura baltica sp. n. (♀): 45 lateral habitus (holotype) 46 dorsal habitus (paratype) 47 dorsolateral head and antennae (holotype) 48 frontolateral head and antennae (paratype) 49 dorsal mesosoma (paratype) 50 middle part of fore wing (paratype).

only slightly convex. Tegula elongate-triangular with almost truncate posterior margin. Mesoscutum (Figs 46, 49) slightly shoulder-like posterior to pronotum, very slightly wider than long, and with parallel, posteriorly ridge-like parapsidal lines (Fig. 49: psr) differentiating median region from inclined lateral regions, median region slightly concave posteriorly but convex anteriorly where delineated laterally by shallow, convergent furrows (Figs 49, 51: fur) originating mesal to respective spiracle (Figs 49, 51: sp); uniformly setose; median mesoscutal region mesh-like reticulate, reticulations isodiametric anteriorly but more elongate posteromedially; parapsidal lines with much smaller and finer sculpture; lateral mesoscutal region with fine sculpture dorsally graduating to mesh-like sculpture ventrally (Fig. 51). Scutellaraxillar complex with distinct, longitudinally crenulate scutoscutellar sutures (Fig. 49: sss) differentiating convex axillae and scutellum; axillae equilateral-triangular with contiguous inner angles, sparsely setose and with much finer and smaller coriaceous sculpture compared to mesoscutum; scutellum with longitudinal carina along side extending from apex of axilla (Fig. 49: scc) and with frenum occupying about 0.15 median length differentiated by transverse, curved line (Fig. 49: fra), frenum bare, isodiametric-reticulate to coriaceous with evenly curved posterior margin, the margin not noticeably protuberant medially or ventrally but separated slightly from underlying metanotum, and scutellum anterior to frenum bare medially but otherwise sparsely, uniformly setose with setae not lengthened posteriorly, and mesh-like coriaceous with sculpture becoming more elongate laterally. Metanotum mostly concealed, but differentiated into lateral panels and dorsellum; dorsellum with convex posterior surface and flat dorsal surface extending from under scutellum slightly beyond apex (Fig. 49: dor). Propodeum mostly concealed but transverse and apparently without differentiated plical and callar regions except for sulcus extending from anterior margin to about level of posterior margin of spiracle adjacent to outer margin of spiracle; crenulate along anterior margin and broad, shallowly incurved foraminal margin (Fig. 52: pfr); spiracle (Fig. 52: sp) comparatively large, anterior margin separated from anterior margin of propodeum by distance about equal to its own diameter and posterior margin at about midlength of propodeum; callar region setose lateral to spiracle (Fig. 52). Prepectus (Figs 48, 51) equilateral triangular, about as long as high, with dorsal and ventral margins forming obtusely rounded posterior angle extending to base of tegula; mesh-like reticulate except much more finely coriaceous along dorsal and ventral margins. Mesopleuron with uniformly convex acropleuron extending virtually to metapleuron and base of mesocoxa, but acropleuron separated from mesocoxa by transverse, bare, strigose-punctulate lower mesepimeron (Fig. 52: lep) that extends dorsally as linear band between acropleuron and metapleuron (Fig. 52: uep); acropleuron differentiated by crenulate acropleural sulcus (Fig. 51: acs) directed straight forward from mesocoxa for about half length of mesopleuron where evenly curved dorsally to near apex of prepectus, bare, distinctly though finely mesh-like coriaceous anteriorly in angle between acropleural sulcus and tegula, but sculpture faded dorsally and posteriorly so as to be smooth and shiny below base of wings and over at least posterior third; mesepisternum setose ventral to acropleural sulcus (Fig. 51: mes). Metapleuron (Fig. 52: pl 3) uniformly setose, triangular, with anterior and posterior margins converging ventrally and extending to base of mesocoxa between acropleuron/mesepimeron and metacoxa. Mesosternum with sulcate discrimen (Fig. 53: dsc), without transepisternal sulcus, and posterior to mesofurcal pit (Fig. 53: mfp) with slender marginal rim (Fig. 53: msr) abutting mesocoxae. Presence or absence of protibial spicule not visible. Middle leg not lengthened conspicuously, at most about as long as hind leg (Fig. 45); meso-

Figures 5Ι–56. Aspidopleura baltica sp. n. (♀ holotype): 5Ι lateral mesosoma and base of gaster (holotype) 52 posterior third of mesosoma, lateral view (holotype) 53 ventrolateral head and ventral mesosoma 54 lateral gaster 55 mesotarsus and tibial spur, dorsal view 56 apex of mesotibia and basitarsus, lateral view.

coxa with large basolateral cavity opposite angle formed between acropleuron and mesepisternum (Figs 51, 53: mcc); mesotibia with two rows of distinctly differentiated, spine-like pegs apically (Fig. 56: map), and with mesotibial spur only about 1.5x as long as apical width of tibia; mesotarsus slender (Fig. 55), apparently with spine-like setae along posterior ventral margin and more peg-like spines along anterior ventral margin of at least basitarsus (Fig. 56), and with distinct peg distally on basal four segments (Fig. 55: pg). Hind leg with tibia and tarsus slender. Fore wing with large brownish region behind marginal and postmarginal veins, color fading distally and not extending over speculum (Fig. 46); costal cell bare except narrowly setose along leading margin; basal cell broadly bare along submarginal vein except apically; disc uniformly setose except for elongate-rectangular speculum contiguous with parastigma and basal fold to cubital fold (Fig. 50: spc); cubital and vannal areas bare; basal fold pigmented apically, forming spur of parastigma (Fig. 50); cc: mv: pmv: stv = 5.5: 2.7: 3.0: 1.3; stigmal vein apically curved into distinct uncus. Gaster (Fig. 54) very broadly sessile, with seven uniformly setose and coriaceous-aciculate gastral tergites; structure of syntergum not clearly visible, but apparently shorter than Gt 6; hypopygium extending about half length of gaster (Fig. 54: hyp) Ovipositor sheaths (Fig. 54: ovs) projecting, but by distance only about equal to length of basitarsus of middle leg.

Biology. Unknown, but the short ovipositor sheaths and bidentate mandibular structure similar to typical members of Anastatus Motschulsky (Eupelminae) might indicate the species was an egg parasitoid.

Remarks. Unlike the previous two described taxa, A. baltica does not closely resemble species of any extant neanastatine genus. It is uniquely distinguished by a large fore wing speculum (Fig. 50: spc) that extends to the cubital fold and is contiguous with the parastigma and basal fold. It is also the only neanastatine to have a distinct frenum (Fig. 49: fra), though the transverse apical scutellar region of Eopelma (Figs 11, 12: smr) and the much less conspicuous scutellar rims of other extant Neanastatinae (Figs 14, 16, 18: smr) may represent secondary modifications that are homologous with a frenum. Its pronotal-mesoscutal structure is also unusual because the mesonotum is slightly shoulder-like posterior to a dorsally transverse pronotum and the mesoscutum is convex anteriorly and shallowly concave posteriorly between convex lateral lobes (Fig. 49). This structure more closely resembles typical winged female Eupelminae (see figs in Gibson 1995) than other Neanastatinae and is a consequence of the almost vertical pronotum of A. baltica not extending posteriorly over the anterior part of the mesoscutum as much as in extant Neanastatinae , which have longer pronota (Figs 1–4, 27, 33). I am uncertain of the mesotarsal peg pattern of A. baltica . The mesotarsus at least has stronger spines forming a more or less double row along its anterior ventral margin (Fig. 56) similar to some Metapelma and Neanastatus . The most apical spine of each segment may also be on a higher plane on the anteroapical margin of the respective segment because they are seen from a somewhat dorsal view (Fig. 55: pg) and, if so, the mesotarsal peg pattern of A. baltica is similar to the pattern that characterizes extant Neanastatinae (Figs 8–10).