Seticornuta Morley, 1913

Alvarado, Mabel, 2022, Darwin wasps of the genus Seticornuta Morley, 1913 (Ichneumonidae: Metopiinae) in the Neotropical region, with a key to species, European Journal of Taxonomy 839, pp. 149-175 : 150-153

publication ID	https://doi.org/ 10.5852/ejt.2022.839.1939
publication LSID	lsid:zoobank.org:pub:E4615884-F227-4551-AB5A-A60482E8DE37
DOI	https://doi.org/10.5281/zenodo.7198549
persistent identifier	https://treatment.plazi.org/id/486ED01F-FFD4-FFD3-FDB3-FA467752118D
treatment provided by	Felipe
scientific name	Seticornuta Morley, 1913
status

Treatment

Genus Seticornuta Morley, 1913 View in CoL View at ENA

Megatrema Cameron, 1907: 468 ,

(type species: Megatrema albopilosa Cameron , by monotypy. [Junior homonym of Megatrema Leach, 1925 ]).

Seticornuta Morley, 1913: 310 View in CoL ,

(type species Seticornuta albicarcar Morley (= albopilosa Cameron ), by original designation.

Diagnosis

Seticornuta can be distinguished from all other genera of Metopiinae Förster, 1969 by the combination of the following characters: (1) upper part of face weakly projected between bases of antennae, not reaching the frons; (2) toruli dorsally surrounded by a carina; (3) sculpture between the toruli and compound eyes similar to the rest of the frons; (4) fore wing with an enclosed areolet; (5) protibial spur antero-dorsally with comb and postero-dorsally with velum; (6) laterotergite II 0.4–0.7 × as wide as long, generally overlapping mid-ventrally.

Redescription

HEAD. Mandibles weakly tapering towards apex, ventrally straight, not twisted, with upper tooth longer than lower tooth; without ventral flange; labrum conspicuously exposed or not when mandible closed; palp formula 5:4, maxillary palpomeres slender; clypeus transverse, its apical margin weakly concave, straight or rarely convex; face+clypeus moderately convex (tentorial pit not located in an elevation); upper part of face produced upwards into a small tooth between bases of antennae (this projection not reaching median ocellus), dorsally not forming a crest medially; frons with a carina surrounding toruli, next to toruli, laterally, without striations; occipital carina complete, ventrally absent or dorsally present, if incomplete ventrally not curved inwards; postgenal bridge not projecting.

MESOSOMA. Pronotum polished with band of setae along dorsal margin, with a longitudinal concavity parallel to anterior margin, upper edge without a shallow submarginal groove, with a ventral pronotal pit, epomia absent; propleuron not swollen; mesoscutum weakly convex, without notauli, without a concavity next to lateral margin; scutoscutellar groove broad and smooth; scutellum tapering towards posterior end, with lateral carinae only reaching over prescutellar ridge; mesopleuron moderately swollen without sternaulus; epicnemial carina complete, laterally convergent with anterior margin of pleuron until near upper end, where it is sharply turned forwards to reach margin almost at level at subalar prominence, rarely interrupted preapically; subalar prominence convex to weakly flattened (not forming a carina-like projection or a horn); mesopleural suture discernible, smooth bellow speculum; posterior transverse carina present laterally and centrally (absent in front of coxae); metapleuron almost flat, polished, glabrous, with a narrow concavity along dorsal margin, ventrally with a weak submetapleural carina which expands into a small lobe anteriorly. Propodeum with lateral longitudinal carina weak but discernible, absent anterior to spiracle, rarely evenly absent or complete; lateromedian longitudinal carinae strong, parallel, back to posterior transverse carina converging to form a single carina that joins margin of propodeal insertion; anterior transverse carina absent; posterior transverse carina generally complete, sometimes weak, and rarely absent; propodeal spiracle oval to elliptical. Pro- and mesotrochantellus undifferentiated, rarely protrochantellus distinctly differentiated; protibial spur antero-dorsally with comb and postero-dorsally with velum; protarsomeres 2–4 wider than long; pretarsal claws simple; mesotibia with two spurs, outer spur slightly longer than inner spur; metatibia without a comb on inner margin, with two spurs, outer spur shorter than inner spur; metatarsomere 5 without a hooked lobe on inner side of distal metatarsomeres of female. Fore wing with enclosed areolet, petiolate; cua-a far distal to base of Rs&M; 2m-cu with one bulla. Hind wing with distal abscissa of Cu1 joining cu-a closer to 1A than to M.

METASOMA. Tergite I with lateral and lateromedian longitudinal carinae quite well developed, spiracle 0.3–0.4 × of way along tergum; sternum I short, ending anterior to spiracle; laterotergite II 0.4–0.7 × as wide as long; laterotergite III 0.5–0.8 × as wide as long; laterotergites of metasomal segments III and IV of female and male separated by crease; metasomal terga VI–VIII without setae on distal margin; metasomal tergite VIII of female entirely flat; female with sterna IV–VI weakly sclerotized with membranous areae; female with sternum VI slightly longer than wide and posteriorly more or less straight; male with metasomal tergites VIII+IX medially divided; male with sternum VIII wider than long, lateral margins converging distally, distal end projecting centrally; paramere distally flat, in lateral view more or less diagonal; apodemes of aedeagus shorter than aedeagus.

Remarks

Seticornuta is most similar to Leurus Townes, 1946 ; some species of Leurus have an enclosed areolet and laterotergites wide and overlapping mid-ventrally, as in Seticornuta . They can be distinguished by the number of labial palp segments, four in Seticornuta and three in Leurus ( Alvarado 2018) , and the shape of the mandible as several species of Leurus have a conspicuous ventral flange that is absent in Seticornuta .

It should be noted that the New World species assigned to Seticornuta differ markedly from those in the Old World. The Old World species were referred to as the albopilosa species group by Gauld & Sithole (2002), on the basis of the difference of the labrum exposed or enclosed. Additionally, the Old World species differ from the New World in the following: pronotum with wrinkles projecting upwards from ventral pronotal pit to the epomia (vs smooth), with epomia present (vs absent); hind wing without basal hamulus (vs with one hamulus); metapleuron with rugae below and parallel to juxtacoxal carina (vs smooth); and antenna with 40–50 flagellomeres (vs 21–34). Illustrations for the Old World species can be found in Choi et al. (2015). In general, Old World species are larger, for example, the length of the fore wing length 1.0– 1.1 mm (vs 3.6–6.7 mm); also, they are predominantly black ( Fitton 1984) while the New World species, especially the Neotropical ones, present a wide variety of colors as is found in the species described here.

Key to species of Seticornuta Morley, 1913 occurring in the Neotropical region

1. Labrum not exposed when mandibles closed ( Fig. 10A View Fig ); metapleuron with dorsal margin evenly declivous ( Fig. 10C–E View Fig ) or if dorsal margin weakly declivous, posteriorly evenly declivous, so is curved ( Fig. 10F–H View Fig ) ......................................................................................................................... 2

– Labrum exposed when mandibles closed ( Figs 1B View Fig , 4B View Fig , 5C View Fig ); metapleuron with dorsal margin weakly declivous, posteriorly abruptly down-turned, forming an angle ( Fig. 10I–K View Fig ) ................................. 8

2. Predominantly metallic blue ( Fig. 3A View Fig ); antenna with 21 flagellomeres ............................................. ................................................................................................................ Seticornuta cuckoo sp. nov.

– Variously colored but never with metallic gloss; antenna with 26–34 flagellomeres ....................... 3

3. Mesoscutum yellow or tawny with three black vittae ( Figs 7C View Fig , 9A View Fig ); face+clypeus yellow ( Figs 7B View Fig , 9B View Fig ) .................................................................................................................................................... 4

– Mesoscutum homogeneously black; face+clypeus entirely black ( Figs 2C View Fig , 6B View Fig , 8C View Fig ) or black with upper half of face yellow ( Fig. 10A View Fig ) ................................................................................................ 5

4. Pronotum with upper half yellow; propodeum without posterior transverse carina ( Fig. 7C View Fig ); epicnemial carina interrupted subapically ........................................................ S. nigroflava sp. nov.

– Pronotum with upper half tawny; propodeum with posterior transverse carina ( Fig. 9A View Fig ); epicnemial carina complete ........................................................................................................... S. rufa sp. nov.

5. Metasomal tergites entirely black, tergite I with lateromedian carinae extending more than 0.9 × length of tergite ................................................................................................................................. 6

– Metasomal tergites II–IV black, laterally yellow; tergite I with lateromedian carinae extending 0.2– 0.3 × length of tergite ........................................................................................................................ 7

6. Occipital carina incomplete, present only dorsally; malar space 0.5 × as long as basal mandibular width ..................................................................................................................... S. quilmes sp. nov.

– Occipital carina complete; malar space 0.7 × as long as basal mandibular width .............................. .............................................................................................................................. S. carinata sp. nov.

7. Lower face black with a yellowish spot ( Fig. 10A View Fig ); gena predominantly black with orbit yellowish red ( Fig. 10B View Fig ); propodeum with posterior transverse carina present between lateral and lateromedian longitudinal carinae ......................................................................................... S. cortesi Porter, 1998 View in CoL

– Lower face black ( Fig. 6B View Fig ); gena entirely black ( Fig. 6A View Fig ); propodeum with posterior transverse carina absent between lateral and lateromedian longitudinal carinae ..................... S. muqui sp. nov.

8. Metasoma black with tergites VI+ reddish brown; frons centrally reddish brown ............................ ....................................................................................................... S. cryptica Gauld & Sithole, 2002 View in CoL – Metasomal tergites black; frons centrally black or yellow ............................................................... 9

9. Mesoscutum homogeneously tawny ( Figs 1C View Fig , 4C View Fig ); gena light yellow, posterodorsally black ( Figs 1A View Fig , 4A View Fig ) .................................................................................................................................................. 10

– Mesoscutum yellowish with three brownish black vittae ( Fig. 5B View Fig ); gena entirely yellow ( Fig. 5B View Fig ) ...........................................................................................................................................11

10. Scape ventrally off-white ( Fig. 1B View Fig ); pronotum antero-ventrally black and postero-dorsally off-white ( Fig. 1A View Fig ); tergite I 0.7 × as long as posteriorly wide ...................................... S. anchanchu sp. nov.

– Scape black ( Fig. 4B View Fig ); pronotum predominantly tawny ( Fig. 4C View Fig ); tergite I 0.9 × as long as posteriorly wide ..................................................................................................................... S. curupira sp. nov.

11. Propodeum, metapleuron and metatibia black; malar space 0.2 × as long as basal mandibular width .......................................................................................... S. altamirae Gauld & Sithole, 2002 View in CoL

– Propodeum, metapleuron and metatibia yellow; malar space 0.6 × as long as basal mandibular width ............................................................................................................................................... 12

12. Metasomal tergites black; interocellar area black ( Fig. 5A–B View Fig ); propodeum with posterior transverse carina strong and complete ........................................................................................ S. flava sp. nov.

– Metasomal tergites brown; interocellar area yellowish; propodeum with posterior transverse carina weak and incomplete .................................................... S. jacutinga Araujo & Penteado-Dias, 2012