Oreiscelio Kieffer, 1910

Talamas, Elijah, Johnson, Norman, van Noort, Simon, Masner, Lubomir & Polaszek, Andrew, 2009, Revision of world species of the genus Oreiscelio Kieffer (Hymenoptera, Platygastroidea, Platygastridae), ZooKeys 6 (6), pp. 1-68 : 3-6

Oreiscelio Kieffer

Oreiscelio Kieffer, 1910a: 293 . Original description. Type: Oreiscelio sechellensis Kieffer , by monotypy and original designation. Kieffer, 1913: 223 (description); Muesebeck and Walkley, 1956: 377 (citation of type species); Sundholm, 1970: 375 (key to species); Masner, 1976: 16 (description); Johnson, 1992: 450 (catalog of world species).

Scelio (Oreiscelio) Kieffer, 1910b: 62 , 73 (description, list of species, change to subgeneric status, keyed).

Oriscelio Kieffer, 1912: 58 (description); Kieffer, 1926: 266, 346 (description, keyed); Nixon, 1933: 290, 292 (description, keyed).

Original concept: urn:lsid:zoobank.org:act:B83E57E6-38E3-4EBB-A6E9-89917230A7FF

Diagnosis. Oreiscelio is distinguished from other genera of Scelionini sensu Masner (1976) by the combination of the bidentate or bispinose metascutellum, the presence of a transverse frontal carina, the strongly transverse antennomeres A4–A6, the developed inner propodeal projection, and the presence of an apically pointed S6 which is sometimes developed into a spine. Additionally, some species of Oreiscelio have a preocellar pit that may be conspicuous. Among the Platygastroidea, this structure was previously known only in the subfamily Telenominae ( Bin and Dessart, 1983) . The “horizontal flaps” of the posterior margin of the propodeum were used by Nixon (1933) as one character diagnostic for this genus. However, one new species, O. paradoxus , has the outer projection of the propodeum rounded (Figs 92, 94) and the typical “flap” is not present.

Description. Length 2.1-4.1 mm; body moderately elongate, robust; body dark brown to black; macropterous.

Head: In dorsal view weakly transverse; vertex coarsely sculptured; hyperoccipital carina absent; occipital carina well-developed, continuous medially; lateral ocellus distinctly separated from inner orbit of compound eye, OOL less than diameter of lateral ocellus; compound eye large, apparently glabrous; frons shallowly concave, transverse carina marking dorsal margin of frontal depression; interantennal process present, short, often excavate medially; submedian carina absent; orbital carina absent; lower frons, including cheek, without fanlike striae; inner ocular orbits diverging ventrally; clypeus very short, strongly transverse, slightly convex to emarginated medially, subequally divided by transverse carina into anteclypeus and postclypeus; malar sulcus present; gena strongly expanded, sculpture variable; labrum hidden behind clypeus; mandible of moderate length, apex with two apical, acute, teeth; ventral mandibular tooth may be smaller, equal or significantly larger than dorsal tooth; maxillary palpus 3-segmented, all segments cylindrical; labial palpus 2-segmented; antenna 12-merous in both sexes; radicle inserted apically into A1, nearly parallel to longitudinal axis of A1; A1 more or less cylindrical, ventral surface flattened; A2 with distinctive elongate seta at ventral apex, seta in females usually extending beyond apex of A3; A 3 in females shorter than A2; A4–A6 strongly transverse; A7 distinctively the largest clavomere; basiconic sensilla on female antenna arranged in longitudinal pairs on apical antennomeres; claval formula A12–A7:1-2-2-2-2-2; male antenna with tyloid on A5.

Mesosoma: In dorsal view longer than wide, in lateral view longer than high; pronotum in dorsal view broad laterally, anterolateral corners angulate; transverse pronotal carina weakly indicated or indistinguishable from coarse surface sculpture; vertical epomial carina present; dorsal epomial carina present; anterior face of prono-tum vertical, not visible in dorsal view; lateral face of pronotum facing anterolaterally, deeply concave below dorsal epomial carina; netrion present, wide, widening ventrally, open; anterior margin of mesoscutum horizontal, not flexed ventrally to meet pronotum; mesoscutum pentagonal in outline, posterolateral corner rounded; parapsidal line sometimes visible; notaulus sometimes distinguishable amid sculpture; skaphion absent; transscutal articulation well-developed; mesoscutellum semicircular, quadrate or trapezoidal, convex, posterior margin convex to deeply notched, sometimes with medial longitudinal furrow; axilla small, dorsal margin sinuate; metanotum narrow, metascutellum clearly differentiated, apex bidentate; dorsal surface of propodeum sparsely setose; inner and outer propodeal projections usually well-developed, fairly short, approximately equal in length, sometimes slightly curved; posterior face of propodeum areolate to irregularly reticulate, sparsely setose, with small to large areolae medially; mesopleural depression well-developed; mesopleural carina present or indicated by rows of small ridges or punctures; anteroventral portion of mesepisternum strongly sculptured to smooth with few punctures; sternaulus not distinguishable; postacetabular foveae not distinguishable; mesopleural pit present, distinct; anterior margin of ventral portion of mesepisternum and acetabular carina transverse, not extended forward between forecoxae; mesepimeral sulcus absent or indicated by dorsoventral line of foveae; posterodorsal corner of mesepimeron prominent, rounded or angulate, not produced into sharp posteriorly directed tooth; mesopleuron usually with strong longitudinal ledge below subalar pit, dorsally delimiting mesopleural furrow; anteroventral portion of metapleuron continuous with lateral face, sparsely setose to glabrous; metapleural triangle present, often divided into two distinct cells, ventral cell longitudinal, often setose; metapleural epicoxal carina present; paracoxal sulcus present as a dorsoventral line of strong setigerous foveae extending to dorsal apex of metapleural triangle; metapleural epicoxal sulcus present as a line of foveae; metapleural sulcus present, sometimes diffi cult to distinguish amid coarse sculpture; metapleural pit present, sometimes diffi cult to distinguish amid coarse sculpture; posterior margin of metapleuron narrowly lamellate; legs not unusually proportioned, often rather short; posterior surface of hind coxa smooth, sparsely setose to glabrous; trochantellus absent; tibial spur formula 1-1-1; tarsal formula 5-5-5; pretarsal claws simple.

Wings: Hyaline to infuscate; submarginal vein (Sc+R) straight, extending at most through basal 0.5 of length of forewing, curved costad apically, bifurcating near apex before reaching costal margin, r-rs straight, R1 ending near costal margin, postmarginal vein absent; bulla absent; no other tracheate veins in forewing; hindwing with tracheate portion of R present only basally; three hamuli present.

Metasoma: Generally flattened dorsally, S2 the largest and most convex, subsequent sternites becoming flatter posteriorly; female with 6 terga, 6 sterna visible externally, male with 8 terga, 7 sterna visible externally; submarginal ridge well-developed, defined by narrow laterotergites to form submarginal rim; no spiracles visible; all terga with distinct reticulation or longitudinal striae throughout, basal rows of crenulae present on each segment, continuous with striae or reticulation; base of T1 with submedial depressions into which inner propodeal angles fit, depressions shallow to deep; T1 with sublateral keel or carina; female T6 without median raised field of microsetae or secretion; S1 not laterally compressed; anterior margin of S2 straight; felt fields on S2–S5 highly reduced, present only as slight differences in sculpture or setation; S 4 in male smooth; S 6 in female pointed apically, sometimes with an apical spine extending beyond the apex of T6; sculpture of S6 punctate reticulate.

Comments. Oreiscelio can be distinguished from Heptascelio by the strongly transverse A4–A6, bidentate metascutellum, and the lack of conspicuous felt fields on the metasomal sterna (Johnson et al. 2007). Among the genera of the Scelionini , only Oreiscelio , some Scelio , and Heptascelio are known to have the conspicuous, elongate seta arising from the ventral side of the apex of A2. In Heptascelio this seta is usually present only in the males, while in Oreiscelio it is found in both sexes. Its function is unknown.

Two years after describing this genus, Kieffer (1912) published a description of Oriscelio, labelling it as a new genus, with the sole species Oriscelio seychellensis , it also labelled as a new species. Muesebeck and Walkley (1956) treated these names as emendations of the names Oreiscelio and O. sechellensis , respectively. We do not consider Kieffer’s 1912 description of Oriscelio to be an emendation because it makes no mention of the 1910 publication, or the names therein, and thus does not fulfill article 33.2 of the Code. Consequently, we agree with Masner (1976) that the similar generic name was an error by Kieffer and do not render Oriscelio as available.

Link to distribution map. 10 Oreiscelio is found widely through sub-Saharan Africa, as well as Madagascar, the Seychelles, and the Arabian Peninsula.