Brachycyrtus Kriechbaumer, 1880

Nascimento, Alexsandra C. & Fernandes, Daniell R. R., 2024, Synopsis of Brachycyrtus Kriechbaumer, 1880 (Hymenoptera: Ichneumonidae: Brachycyrtinae) from Brazil, with description of two new species, Zootaxa 5430 (1), pp. 1-62 : 7-17

publication ID	https://doi.org/ 10.11646/zootaxa.5430.1.1
publication LSID	lsid:zoobank.org:pub:5D688E51-9C95-40E5-B4A5-1B626541E0F7
persistent identifier	https://treatment.plazi.org/id/03B4D46B-FF80-E30D-32CC-A924FA2EFE93
treatment provided by	Plazi
scientific name	Brachycyrtus Kriechbaumer, 1880
status

Treatment

Brachycyrtus Kriechbaumer, 1880 View in CoL View at ENA

Brachycyrtus Kriechbaumer, 1880: 161 View in CoL . Type-species: Brachycyrtus ornatus Kriechbaumer, 1880 View in CoL (mon.).

Proterocryptus Ashmead, 1906: 174 . Type-species: Proterocryptus nawai Ashmead, 1906 (mon.); Roman 1915 (syn.). Xanthocharops Morley, 1912: 173 . Type-species: Xanthocharops primus Morley, 1912 (mon.); Townes & Townes 1960 (syn.). Vakau Cheesman, 1928: 189 . Type-species: Vakau taitensis Cheesman, 1928 (mon.); Townes 1945 (syn.).

Brachycyrtomorpha Blanchard, 1942: 105 . Type-species: Brachycyrtomorpha crossi Blanchard, 1942 (mon.); Townes 1945 (syn.). Habryllia Walkley, 1956: 318 . Type-species: Habryllia cosmeta Walkley, 1956 (mon.); Wahl 1993 (syn.).

Diagnosis. Occipital carina complete, joining hypostomal carina or base of the mandible; mesosoma short; propodeum short abruptly declivous posteriorly, usually with complete set of carinae; fore wing with 1cu-a distal to M& RS by at least 0.5 its length, often by its own length or more; fore wing without areolet, 3rs-m absent; 2m-cu close with two bullae, or rarely with one; hind wing with abscissa of CU spectral.

Redescription. Body small, 3.59–7.99 mm. Head. Flagellum often slender to distinctly clavate. Occipital carina complete, joining hypostomal carina or base of the mandible. Eyes nearly parallel to ventrally converging, inner margin eye with a shallow to deep impression opposite antennal insertion. Front flat to weakly convex, without median vertical carina. Clypeus small, in profile more or less flat, not separated from face by a distinct groove, its apical margin truncate or gently rounded and convex, without teeth. Labrum small and partially exposed. Malar space from strongly reduced to nearly as long as mandible base. Mandible short and wide, bidentate but with the upper tooth apically indented so that the mandible appears tridentate. Mesosoma. Short. Mesoscutum with notaulus vestigial sometimes impressed and with a small crest anteriorly. Scutellum usually laterally carinate. Scuto-scutellar groove with or without longitudinal ridges. propodeum short abruptly declivous posteriorly, usually with complete set of carinae; propodeal spiracle circular to oval; propodeal carinae variously developed, often with area superomedia joined to area petiolaris. Pronotum with epomia from almost absent and distinct only ventrally to strong and complete. Mesosternal region short, sometimes strongly reduced so that the ventral part the of epicnemial carina almost adjacent to mid coxa, attaining the position of the posterior transverse carina of mesosternum; sternaulus short or absent. Apex of fore tibia without a tooth on outer side; hind coxa in female without a vertical or oblique groove on inner side; hind tibia with a fringe of close long hairs on inner side; insertion of tibial spurs in an area confluent with the tarsus 1; tarsal claw simple. Wing length 2.9–5.8 mm; fore wing with 1cu-a distal to M& RS by at least 0.5 its length, often by its own length or more; fore wing without areolet, 3rs-m absent; 2m-cu close with two bullae, or rarely with one; hind wing with abscissa of CU spectral. Metasoma. Tergite 1 fused with sternite, without dorsolateral carina and with spiracle near its apical 0.35; glymma absent; tergites 2–4 with pendant laterotergites; thyridium on tergite 2 present or absent. Ovipositor usually straight, rarely downcurved, extending beyond apex of metasoma. Male. Usually with aedeagus, moderately stout, subcynlindrical apically rounded. This diagnosis was based on Kriechbaumer (1880), Cushman (1936), Walkley (1956), Townes & Townes (1960), Townes (1969), Gauld & Ward (2000) and Bennett (2009).

Distribution. Nearctic . Canada and USA. Neotropical. Argentina, Brazil, Costa Rica, Ecuador, Mexico, Panama, Peru, Suriname, Trinidad and Tobago, and Venezuela. Afrotropical. Seychelles Islands, Madagascar, Kenya, Uganda and Zimbabwe. Palearctic. Germany, Austria, Bulgaria, Croatia, Spain, France, Czech Republic, Czechoslovak Republic, Iran, Yugoslavia, Macedonia, Moldova, Poland, Romania, Sweden and Turkey. Oriental. China, Philippines, India and Japan. Australian. Australia, Fiji, American Samoa and Tahiti ( Kriechbaumer 1880; Ashmead 1906; Roman 1915; Cheesman 1928; Cushman 1936; Seyrig 1952; Walkley 1956; Gonçalves 1973; De Santis 1980; Gauld & Ward 2000; Kumagai & Graf 2000; Bennett 2009; Onody et al. 2009; Quicke et al. 2009; Sudheer 2009; Yu et al. 2016; Fernandes et al. 2020a; Fernandes et al. 2020b; Di Giovanni & Varga 2021; Fernandes et al. 2023).

Biology. According to the existing records, species of Brachycyrtus are solitary ectoparasitoids of the cocooned pupae and prepupae of Chrysopidae ( Neuroptera ) ( Short 1959; Gauld & Ward 2000). However, it is worth noting that the antenna in the larval stage has not yet been observed, and this structure is essential to help confirm whether Brachycyrtus is an ecto or endoparasitoid, since no ectoparasitoid is known to have a disc-shaped antenna ( Wahl 1993; Yanez et al. 2020). Late instar larvae of Brachycyrtus have typical ectoparasitoid features: 1) dorsal margin of denticulated mandibular blade; 2) labral sclerite present and 3) spiracular closure apparatus separated from the atrium by a section of the trachea ( Short 1978; Wahl 1993).

Key to the species of Brachycyrtus Kriechbaumer View in CoL , from Brazil (adapted from Gauld & Ward 2000)

1 Propodeum with area superomedia separated from area petiolaris by posterior transverse carina ( Fig. 5A View FIGURE 5 ); tergite 2 with a strong oblique thyridium anteriorly ( Fig. 6A View FIGURE 6 ); eye with a deep V-shaped impression opposite antennal insertion ( Fig. 7A View FIGURE 7 )........................................................................ Brachycyrtus pretiosus Cushman, 1936 View in CoL

1’ Propodeum with area superomedia confluent with area petiolaris ( Fig. 5B View FIGURE 5 ); tergite 2 without thyridium ( Fig. 6B View FIGURE 6 ); eye with a shallow impression opposite antennal insertion ( Fig. 7B View FIGURE 7 )..................................................... 2

2 (1’). Propodeum granulate and weakly polished ( Fig. 8A View FIGURE 8 )......................................................... 3

2’ Propodeum without granulate and polished, but sometimes with sparse punctures ( Fig. 8B View FIGURE 8 ).......................... 6

3 (2) Propodeum with anterior transverse carina absent, making the area dentipara and the area externa confluent ( Fig. 9A View FIGURE 9 ); flagellum uniformly blackish above ( Fig. 10A View FIGURE 10 )................................... Brachycyrtus veriatrix Gauld & Ward, 2000 View in CoL

3’ Propodeum with anterior transverse carina complete present separating the area dentipara from the area externa ( Figs. 9B View FIGURE 9 ) or incomplete; flagellum yellowish brown, with distal apex darked, with or without a whitish band ( Fig. 10B View FIGURE 10 ).............. 4

4 (3) Propodeum with posterior transverse carina incomplete laterally and centrally, area coxalis not anteriorly delineated ( Fig. 11A View FIGURE 11 ); head, in dorsal view, with black interocellar mark separated from black occipital mark by an intervening yellow area ( Fig. 12A View FIGURE 12 ); tergite 2 with the division between anterior dark and posterior pallid parts transverse and straight ( Fig. 13A View FIGURE 13 )................................................................................... Brachycyrtus oculatus Cushman, 1936 View in CoL

4’ Propodeum with posterior transverse carina incomplete centrally, area coxalis anteriorly delineated ( Fig. 11B View FIGURE 11 ); head, in dorsal view, with a black interocellar mark confluent with black occipital mark, with no intervening yellow area ( Fig. 12B View FIGURE 12 ); tergite 2 with a division between dark anterior parts and pallid posterior parts, which extended forward into an inverted V-shape on the midline ( Fig. 13B View FIGURE 13 ).................................................................................... 5

5 (4) Mesoscutum with notaulus impressed anteriorly ( Fig. 14A View FIGURE 14 ); antenna with a white band on flagellomeres 18 – 23 ( Fig. 15A View FIGURE 15 ).................................................................... Brachycyrtus convergens Cushman, 1936 View in CoL

5’ Mesoscutum without notaulus ( Fig. 14B View FIGURE 14 ); antenna without white band ( Fig. 15B View FIGURE 15 )................................. 10 6 (2’) Propodeum with area dentipara and area lateralis confluent, area posteroexterna outlined ( Fig. 16A View FIGURE 16 ).................. 11

6’ Propodeum with area dentipara separated from the area lateralis for the lateral longitudinal carina, area posteroexterna not outlined ( Fig. 16B View FIGURE 16 )................................................................................... 7

7 (6’) Mesoscutum predominantly reddish-brown or reddish-yellow without the longitudinal black mark ( Fig. 17A View FIGURE 17 ); ovipositor with upper valve stout, apically rather abruptly rounded or tapered ( Fig. 18A View FIGURE 18 )......................................... 8

7’ Mesoscutum whitish-yellow with three longitudinal black marks ( Fig. 17B View FIGURE 17 ); ovipositor with upper valve apically fairly evenly tapered to apex ( Fig. 18B View FIGURE 18 ).............................................................................. 9

8 (7) Metanotum without the black mark ( Fig. 19A View FIGURE 19 ); propodeum with area posteroexterna separated from area dentipara by the posterior transverse carina, posterior transverse carina present lateromedially.... Brachycyrtus obelix Gauld & Ward, 2000 View in CoL

8’ Metanotum with black mark ( Fig. 19B View FIGURE 19 ); propodeum with area posteroexterna and area dentipara confluent, posterior transverse carina absent.......................................................... Brachycyrtus muesebecki Walkley, 1956 View in CoL

9 (7’) Propodeum with area posteroexterna separated from area dentipara by the posterior transverse carina ( Fig. 20A View FIGURE 20 ) .............................................................................. Brachycyrtus xorix Gauld & Ward, 2000 View in CoL

9’ Propodeum with area posteroexterna and area dentipara confluent ( Fig. 20B View FIGURE 20 )........................................................................................................... Brachycyrtus zani Gauld & Ward, 2000 View in CoL

10 (5) Slightly clavate flagellum, yellowish-brown with a blunted apex, without any trace of a white subapical band ( Fig. 21A View FIGURE 21 ); head dorsal without ocellar carina ( Fig. 22A View FIGURE 22 ); propodeum anterior transverse carina complete ( Fig. 23A View FIGURE 23 ), with area coxalis not anteriorly delineated ( Fig. 24A View FIGURE 24 ), posterior transverse carina present lateromedially...................................................................................................... Brachycyrtus cosmetus ( Walkley, 1956) View in CoL

10’ Slender flagellum, basally reddish-yellow, centrally yellow, and apically dark brown ( Fig. 21B View FIGURE 21 ); head dorsal with ocellar carina connecting the posterior margins of the left and right lateral ocellar fovea ( Fig. 22B View FIGURE 22 ); Propodeum anterior transverse carina incomplete lateromedially ( Fig. 23B View FIGURE 23 ), with area coxalis anteriorly delineated ( Fig. 24B View FIGURE 24 ), posterior transverse carina absent centrally................................................................ Brachycyrtus ocellicarinatus sp. n..

11 (6) Propodeum with area posteroexterna separated from area dentipara by the posterior transverse carina ( Fig. 25A View FIGURE 25 )........................................................................ .. Brachycyrtus walkleyae Gauld & Ward, 2000 View in CoL

11’ Propodeum with area dentipara separated from area lateralis by the lateral longitudinal carina, area posteroexterna not delineated ( Fig. 25B View FIGURE 25 )................................................................ Brachycyrtus amazonensis sp. n.