Introduction
The genus Synosis Townes, 1959 (Hymenoptera: Ichneumonidae: Metopiinae) presently includes 18 described species (Broad and Shaw Reference Broad and Shaw2005; Herrera et al. Reference Herrera, Sobczak and Penteado-Dias2011; Alvarado and Rodriguez-Berrio Reference Alvarado and Rodriguez-Berrio2013). The bulk of its diversity is in the Palaearctic and Neotropical regions; a single species and type of the genus, Synosis clepsydra Townes, 1959, is distributed in the Nearctic region.
The Neotropical fauna was recently documented (Gauld and Sithole Reference Gauld and Sithole2002; Herrera et al. Reference Herrera, Sobczak and Penteado-Dias2011; Alvarado and Rodriguez-Berrio Reference Alvarado and Rodriguez-Berrio2013) and includes six species from three countries: Brazil (S. jundiaiensis Herrera, 2011), Costa Rica (S. ugaldei Gauld and Sithole, Reference Gauld and Sithole2002), and Peru (S. rubinus Alvarado and Rodriguez-Berrio, Reference Alvarado and Rodriguez-Berrio2013, S. cosnipatensis Alvarado and Rodriguez-Berrio, Reference Alvarado and Rodriguez-Berrio2013, S. gauldi Alvarado and Rodriguez-Berrio, Reference Alvarado and Rodriguez-Berrio2013, and S. townesi Alvarado and Rodriguez-Berrio, Reference Alvarado and Rodriguez-Berrio2013).
As part of a continuing revision of South American Metopiinae, more species were discovered. The aim of this paper is to present a more detailed description of the genus, describe three new species, illustrate them, and provide a key for Neotropical species.
Materials and methods
The type specimens were examined for all the Neotropical species, and the type species of the genus. Synosis jundiaiensis Herrera, 2011, was examined using photographs provided by Andrés Fabián Herrera (Department of Biology, Ludwig-Maximilians-University of Munich, Bavaria, German). Specimens studied herein are deposited in the Canadian National Collection of Insects, Arachnids, and Nematodes, Ottawa, Ontario, Canada (CNC); Entomological Museum Klaus Raven Buller, Lima, Peru (MEKRB); San Marcos Natural History Museum, Lima, Peru (MUSM); United States National Museum, Washington, District of Columbia, United States of America (USNM); and Utah State University, Logan, Utah, United States of America (USUC).
Morphological terminology and the format for the species descriptions mostly follow Alvarado and Rodriguez-Berrio (Reference Alvarado and Rodriguez-Berrio2013) except for face + clypeus that now is refers as face and clypeus and the ratio of length from flagellomeres 2 and 3 were added; for the genus redescription mostly follows Gauld and Sithole (Reference Gauld and Sithole2002) except for the tarsal claws that are referred as pretarsal claws and were added features found in the head, pronotum, mesoscutum, protibial spur, and metasomal tergites VI–VIII. The dissection of the female terminalia was performed by severing the metasomal tip. The severed section was cleared in a 10% solution of potassium hydroxide at room temperature for 24 hours and then transferred to water and 96% ethanol prior to long-term storage in glycerin. Photomicrographs were prepared using a Nikon (Tokyo, Japan) D1x digital camera attached to an Infinity (Centennial, Colorado, United States of America) K-2 long-distance microscopic lens (in the laboratories of the Snow Entomological Collection, Division of Entomology, University of Kansas Natural History Museum, Lawrence, Kansas, United States of America). Label data are noted verbatim, with notes in square brackets describing abbreviations, unique identifier labels, and dissections performed.
Genus Synosis Townes
Synosis Townes in Townes and Townes, Reference Townes and Townes1959:168.
Type species. Synosis clepsydra Townes, 1965 by original designation.
Diagnosis.Synosis can be distinguished from all other genera of metopiines by the combination of the following characters: (1) upper part of face produced upwards between bases of antennae, this projection distally slightly concave or straight, dorsally lacking an inter-antennal lamella (Fig. 1A); (2) propodeum with lateromedian longitudinal carinae anteriorly converging into a single carina (Fig. 1C) or close to each other (Fig. 1D–F) then divergent so area superomedia and area basalis are more or less triangular (Fig. 1C–F); (3) metapleuron with a band of setae along the dorsal periphery, elsewhere bare (Fig. 1B); (4) metasomal tergite VIII of female with a concavity centrally near base of tergite (Fig. 1F–G).

Fig. 1. Details of Synosis. A, Facial view, S. clepsydra; B, metapleuron, S. clepsydra; C, propodeum, S. clepsydra; D, propodeum, S. gauldi; E, propodeum, S. rubinus; F, propodeum, S. townesi; G, metasomal tergite VIII of female, S. clepsydra; H, metasomal tergite VIII of female, S. zezei.
Comments. The characters mentioned in the diagnosis are uniquely found in Synosis, except for band of setae along its dorsal periphery that is also present in Stethoncus Townes, 1959 and Hypsicera Latreille, 1829 but in these genera is formed only by fine line of isolate setae.
Redescription.Head. Mandibles weakly tapering towards apex, ventrally straight, without ventral flange; apex not twisted, with upper tooth longer than lower tooth; labrum not conspicuously exposed when mandible closed; palp formula 5:4, maxillary palpomeres slender; clypeus transverse, its apical margin weakly convex; face and clypeus moderately convex (tentorial pit not located in a raised area); without subocular sulcus; upper part of face produced upwards between bases of antennae, this projection distally slightly concave or straight (Figs. 1A, 2C, 3C, 4C), dorsally lacking an inter-antennal lamella (Fig. 3B); frons without a carina surrounding toruli; without striations between toruli and compound eyes; occipital carina absent or present only dorsally; postgenal bridge not projected.

Fig. 2. Details of Synosis diaguita, new species. A, Habitus of female, in lateral view (scale bar = 1 mm); B, habitus of male, in lateral view; C, facial view; D, head and mesosoma in dorsal view.

Fig. 3. Details of Synosis nigra, new species. A, Habitus of female, in lateral view (scale bar = 1 mm); B, head and mesosoma in dorsal view; C, facial view; D, head and mesosoma in lateral view.

Fig. 4. Details of Synosis zezei, new species. A, Habitus of female, in lateral view (scale bar = 1 mm); B, habitus of male, in lateral view (scale bar = 1 mm); C, facial view; D, mesosoma in lateral view; E, head and mesosoma in dorsal view.
Mesosoma. Pronotum polished with band of setae along upper margin, with a longitudinal concavity parallel to anterior margin, upper edge with a shallow submarginal groove, with a ventral pronotal pit, epomia close to and parallel to anterior margin of pronotum with its upper end divergent; propleurae not swollen; mesoscutum rather flat, with notauli impressed, with concavity along lateral margin (between notauli and distal end of mesoscutum); scutoscutellar groove broad, more or less smooth or scrobiculate; scutellum tapering towards distal end, with lateral carinae only reaching over prescutellar ridge; mesopleuron moderately swollen, sternaulus distinct, and extending about 0.3–0.5 the length of the mesosternum; epicnemial carina complete, laterally convergent with anterior margin of pleuron until near upper end, where it turned backwards to reach subalar prominence; subalar prominence 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 (Fig. 1B) almost flat to weakly convex, polished, with a band of setae along its dorsal periphery, elsewhere bare (rarely with isolate setae in remaining surface); submetapleural lobe from weakly expanded to well developed and conspicuous. Propodeum (Fig. 1C–F) with lateral longitudinal carinae complete; lateromedian carinae strongly convergent anteriorly joining into a single carina (Fig. 1C) or, in some species, separated (Fig. 1D–F) but close to each other (in this case with (Fig. 1E–F) or without (Fig. 1D) transverse carina between them), then dividing more posteriorly so that area superomedia and area basalis are more or less triangular, posteriorly reaching back to posterior transverse carina; anterior transverse carina present or absent between pleural and lateral longitudinal carinae, in some species present between lateromedian longitudinal carinae; posterior transverse carina usually complete (except in S. ugaldei); propodeal spiracle round or oval. Protrochantellus and mesotrochantellus distinctly differentiated; protibial spur dorsoanteriorly with a comb and dorsoposteriorly with a velum; protarsomeres 2–3 slightly longer than wide, tarsomere 4 wider than long; pretarsal claws simple; mesotibia with two spurs, outer spur distinctly longer than inner spur; metatibia with inner margin apically with a curved comb, with two spurs, outer spur shorter than inner spur; metatarsomere 5 without a hooked lobe on inner side of female. Fore wing without a trace of an enclosed areolet, cua far distal to base of Rs&M; 2 m-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 well developed, spiracle at 0.3–0.4 anterior of tergite; sternum I short, ending anterior to spiracle; laterotergite II 0.1–0.5 times as wide as long; laterotergites of metasomal segments III and IV separated by a crease; metasomal tergites VI–VIII without setae on distal margin; metasomal tergite VIII of female not folded ventrally, not partly separated by crease, with concavity centrally near base of tergite (Fig. 1G–H); female with sternum VI wider than long, basal, and distal margins more or less straight; male with metasomal tergites VIII + IX medially divided; male with sternum VIII wider than long; paramere distally flat; apodemes of aedeagus shorter than aedeagus.
Natural history. Little is known about the natural history of Synosis, as other metopiine, they are koinobiont endoparasitoids of Lepidoptera, reared from the families Yponomeutidae, Swammerdamia caesiella (Hübner, 1796), and Ypsolopha parenthesella (Linnaeus, 1761) (Broad and Shaw Reference Broad and Shaw2005) and Geometridae, Venusia pearsalli (Dyar, 1906) and unidentified species of Venusia Curtis, 1839 (Lepidoptera: Geometridae) (Bradley Reference Bradley1974).
Synosis clepsydra Townes, 1959
Figure 1A–C, G.
Diagnosis. Propodeum with lateromedian longitudinal carinae anteriorly converging into a single carina, or running close to each other, and anterior transverse carina present only next to lateral longitudinal carina; submetapleural lobe semicircular, scrobiculate; mesosoma predominantly black; and legs reddish brown.
Comments. This species occurs in North America, north of Mexico. It the only Synosis species recorded from Nearctic region. It was reared from Venusia pearsalli (Dyar, 1906) and Venusia species feeding on Malus Miller (Rosaceae) and the Alnus rubra Bongard (Belutaceae) and Alnus species (Bradley Reference Bradley1974).
Examined material. Holotype: 1♀ “United States of America: Camino, Califor. [California] 27 June 1948, MHG & D Townes” (USNM). Paratype: 1 ♀ “Auburndale, Mass., June 17 (Townes)” (USUC). Nontype material. 1♀ “Williamsville, MO 1-8.4.1972 J.T. Becker Malaise Trap [CNC493235]” (CNC), 1♂ “Highlands, N.C. 22.v.1957 W.R.M. Mason [CNC493236, male genitalia extracted]” (CNC), and 1♀ “Jumping Pd. Cr 20 mi. W. Calgary ALTA 19 July W.R.M. Mason′62 [CNC493237, female genitalia extracted]” (CNC).
Synosis diaguita Alvarado, new species
http://zoobank.org/urn:lsid:zoobank.org:act:ECD42955-9AE8-4F43-92E6-A9DF297ADB2B
Figure 2.
Diagnosis. Propodeum with lateromedian longitudinal carinae anteriorly converging into a single carina and anterior transverse carina present between longitudinal carinae; submetapleural lobe semicircular, smooth; mesosoma predominantly black; and female with all legs yellow testaceous and male with legs yellowish testaceous except for metacoxa brown.
Comments.Synosis diaguita is most similar to S. jundiaiensis, from which it can be differentiated by having the scape ventrally yellow (versus black), antenna with 29–31 flagellomeres (versus 27 flagellomeres), and flagellomeres brown (versus black). It is the first Synosis species recorded from Argentina.
Description.Female. Fore wing length 3.4 mm.
Head. Face and clypeus 0.9 times as long as wide (Fig. 2C); malar space 0.9 times as long as basal mandibular width; lateral ocellus separated from compound eye by 1.0 times ocellar diameter (Fig. 2D); distance between lateral ocelli 1.5 times their own maximum diameter; head posteriorly behind ocellar triangle, strongly declivous, and concave; gena, on lateral view 0.7 times as long as compound eyes; occipital carina absent; antenna with 31 flagellomeres, ratio of length from second to fourth flagellomeres: 1.4:1.4:1.4, subapical flagellomere 1.4 times as long as centrally wide.
Mesosoma. Mesoscutum with notaulus extending 0.6 times length of mesoscutum; scutellum flat; scutoscutellar groove smooth (Fig. 2D); metapleuron bare at centre; submetapleural lobe smooth, semicircular. Propodeum with lateromedian longitudinal carinae anteriorly converging but never in contact, with space between them thinner than thickness of both carinae; area basalis and superomedia without setae; area superomedia pentagonal; anterior transverse carina present only between lateral and lateromedian longitudinal carinae. Fore wing with vein cua distal to base of Rs&M by about 0.5 times its own length; Cu1 between 1 m-cu and Cu1a 1.4 times as long as Cu1b; Cu1a between Cu1b and 2 m-cu 1.5 times as long as Cu1 between Rs&M and 1 m-cu; 2 rs-m 0.7 times as long as abscissa of M between 2 rs-m and 2 m-cu. Hind wing with distal abscissa of M not sclerotised; Cu1 faint, but discernible.
Metasoma. Tergite I 1.3 times as long as posteriorly wide, lateromedian carinae extending 0.4 times length of tergite without punctures present between lateromedian carina; tergite II 0.7 times as long as posteriorly wide; laterotergite II 0.2 times as long as wide.
Colour. Head black except extensively yellow on face, malar space, palpi, ventral part of scape, and mandible and brown flagellomeres. Mesosoma (Fig. 2A) predominantly black, except for tegula testaceous, and legs testaceous, metacoxa light brown. Wings hyaline; pterostigma brown.
Variation. The female paratype (fore wing length 3.5 mm) varies in having: lateral ocellus separated from compound eye by 1.1 times ocellar diameter; distance between ocelli 1.6 times its own maximum diameter; antenna with 29 flagellomeres, ratio of length from second to fourth flagellomeres: 1.7:1.7:1.7, subapical flagellomere 1.3 times as long as centrally wide; propodeum with lateromedian longitudinal carinae anteriorly converging into a single carina; metasomal tergite I 1.4 times as long as posteriorly wide; metacoxa testaceous.
Male. Fore wing length 3.3 mm. Similar to the female except: antenna with 29+ flagellomeres, ratio of length from second to fourth flagellomeres: 1.6:1.5:1.5; propodeum with anterior transverse carina complete between longitudinal carinae; metasoma with tergite I 1.4 times; metacoxa light brown (Fig. 2B).
Holotype. ♀ “Amaicha del Valle XII-31–65 Argent. [Argentina] H. & M. Townes” (USUC).
Paratypes. ♀ “Amaicha del Valle XII-31–65 Argent. [Argentina] H. & M. Townes”, and ♂ “Amaicha del Valle XII-29–65 Argent. [Argentina] H. & M. Townes”, left antenna missing and tip of right antenna broken (USUC).
Etymology. The species epithet diaguita refers to the Diaguita people, a group of South American indigenous people native to the Chilean Norte Chico and the Argentine Northwest. It is treated as a noun in apposition.
Synosis gauldi Alvarado and Rodriguez-Berrios, Reference Alvarado and Rodriguez-Berrio2013
Figure 1D.
Diagnosis. Propodeum with lateromedian longitudinal carinae anteriorly converging but never in contact and anterior transverse carina present only between lateromedian longitudinal carinae; submetapleural lobe thin, triangular, smooth; mesosoma predominantly black; and legs yellow but metathoracic leg with coxa, basal and distal ends of tibia, and tarsomeres black.
Comments.Synosis gauldi was only known from the holotype, collected in Cuzco, Peru, at 2052 m (Alvarado and Rodriguez-Berrios Reference Alvarado and Rodriguez-Berrio2013), a second specimen for the species is recorded in Amazonas department. This species occurs in rain forest along the eastern slope of the Peruvian Andes between 2050–2362 m.
Examined material. Holotype: ♀ “PERU: CU, Valle del Qosñipata, Rocotal, 13º06′48″S, 71º34′13″W, 2052 m. 07 January 2008. Malaise trap 10. C. Castillo” (MUSM). Nontype material: ♀, “PERÚ: AM. Abra Patricia Trocha Mono 17.xi.2012 05º41′36″S/ 77º48′41.9″W 2362 m Malaise Trap J. Suárez & P. Sánchez” (MUSM).
Synosis nigra Alvarado, new species
http://zoobank.org/urn:lsid:zoobank.org:act:64E30CBB-343E-41EF-9275-A3FB6BC7C05E
Figure 3.
Diagnosis. Propodeum with lateromedian longitudinal carinae anteriorly converging into a single carina and anterior transverse carina present between longitudinal carinae; submetapleural lobe semicircular, smooth; mesosoma predominantly black; and prothoracic and mesothoracic legs testaceous and metathoracic leg with coxa, femur, and tibia (but ventrally reddish brown) black.
Comments.Synosis nigra is most similar to S. townesi, from which it can be differentiated by the submetapleural lobe semicircular (versus triangular) and distance between lateral ocelli 1.5 times their own maximum diameter (versus 1.0–1.1 times). It is the second Synosis species recorded from Brazil.
Description.Male. Fore wing length 4.9 mm.
Head. Face and clypeus 0.9 times as long as wide (Fig. 3C); malar space 1.2 times as long as basal mandibular width; lateral ocellus separated from compound eye by 0.9 times ocellar diameter (Fig. 3B); distance between lateral ocelli 1.5 times their own maximum diameter; head posteriorly behind ocellar triangle, strongly declivous and concave; gena, on lateral view 0.5 times as long as compound eyes; occipital carina absent; antenna with 39 flagellomeres, ratio of length from second to fourth flagellomeres: 1.6:1.5:1.5, subapical flagellomere 1.6 times as long as centrally wide.
Mesosoma. Mesoscutum with notaulus extending 0.6 times length of mesoscutum; scutellum flat; scutoscutellar groove scrobiculate (Fig. 3B); mesopleuron with epicnemial carina ending at subalar prominence; metapleuron with isolate setae at centre; submetapleural lobe smooth, semicircular. Propodeum with lateromedian longitudinal carinae anteriorly converging into a single carina; area basalis and superomedia bare; area superomedia pentagonal; anterior transverse carina present only between lateral and lateromedian longitudinal carinae. Fore wing with vein cua distal to base of Rs&M by about 0.6 times its own length; Cu1 between 1 m-cu and Cu1a 1.5 times as long as Cu1b; Cu1a between Cu1b and 2 m-cu 1.5 times as long as Cu1 between Rs&M and 1 m-cu; 2 rs-m 0.9 times as long as abscissa of M between 2 rs-m and 2 m-cu. Hind wing with distal abscissa of M not sclerotised; Cu1 sclerotised throughout.
Metasoma. Tergite I 1.3 times as long as posteriorly wide, lateromedian carinae extending 0.4 times length of tergite without punctures present between lateromedian carina; tergite II 0.7 times as long as posteriorly wide; laterotergite II 0.2 times as long as wide.
Colour. Head (Fig. 3C–D) black except extensively yellow on face, malar space, ventral part of scape, and mandibles, and palpi testaceous. Mesosoma predominantly black (Fig. 3D), except for tegula brownish black; prothoracic and mesothoracic legs testaceous; metathoracic leg with coxa, femur, and tibia (but ventrally reddish brown) black (Fig. 3 A), trochanter, trochantellus, and tibial spurs testaceous, and tarsomere brownish testaceous. Wings hyaline; pterostigma brown.
Female. unknown.
Holotype. ♂ “Nova Teutonia 27º11′S 52º23′W BRAZIL, 300–500 m I.1967 Fritz Plaumann [CNC493234]” (CNC).
Etymology. The specific epithet nigra, meaning “black”, is a reference to the colour of the metathoracic leg. It is treated as an adjective in the nominative singular.
Synosis rubinus Alvarado and Rodriguez-Berrios, Reference Alvarado and Rodriguez-Berrio2013
Figure 1E.
Diagnosis. Propodeum with lateromedian longitudinal carinae anteriorly converging but never in contact and anterior transverse carina present; submetapleural lobe triangular, smooth; mesosoma predominantly red except for propodeum and most of metapleuron (except for anterior and dorsal margins red) black; and legs predominantly yellow except for mesothoracic leg with tarsomeres 3–5, metathoracic leg with coxa anteriorly, tibia distally and basally (in the Ecuadorian individual), and tarsomere 5 black.
Comments. It is the first Synosis species recorded from Ecuador. Synosis rubinus was only known to occur in Peru (Alvarado and Rodriguez-Berrios Reference Alvarado and Rodriguez-Berrio2013). It is recorded for the first time in Ecuador. This species occurs in rain forest along the eastern slope of the Andes Mountains between 800–1600 m.
Examined material. Holotype: ♂ “PERU: CU, La Convención, Quillabamba, Poromate, 1600 m. 11 November 2007. A. Rodriguez” (MEKRB). Nontype material: ♂ “Zamora, Ecuador XI.24.70 800 m Luis E. Peña” (USUC).
Synosis townesi Alvarado and Rodriguez-Berrios, Reference Alvarado and Rodriguez-Berrio2013
Figure 1F.
Diagnosis. Propodeum with lateromedian longitudinal carinae anteriorly converging but never in contact and without anterior transverse carina between them; submetapleural lobe triangular, smooth; mesosoma predominantly black, and legs predominantly yellow except for metathoracic leg with coxa, tibia apically, and tarsomeres black.
Comments. It is the second Synosis species recorded from Ecuador. Synosis townesi was only known to occur in Cuzco, Peru (Alvarado and Rodriguez-Berrios Reference Alvarado and Rodriguez-Berrio2013). It is recorded for the first time in Ecuador. This species occurs in rain forest along the slope of the Andes Mountains between 1500–2700 m.
Examined material. Holotype: ♀ “PERU: CU, C.I. Waiqecha, 13º03′21″ S, 71º35′04″ W/, 2662 m. 20 October 2007. Malaise trap 4. C. Castillo” (MUSM); Paratype: ♀ “PERÚ: CU, Cosñipata valley, Rocotal, 2052 m, 13o06′47.7″S/ 71o34′13.3″W 10.xii.2007 Malaise. C. Castillo” (MUSM). Nontype material: ♀, “ECUADOR: Napo, Sierra Azul (Hacienda Aragon), 0.67ºS, 77.92ºW, 2300 m 21–22.iii.1996; P. Hibbs yellow pan traps” (USUC).
Synosis zezei Alvarado, new species
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Diagnosis. Propodeum with lateromedian longitudinal carinae anteriorly converging into a single carina and anterior transverse carina present between longitudinal carinae; submetapleural lobe semicircular, smooth; mesosoma predominantly black; and legs reddish brown.
Comments.Synosis zezei is most similar to S. diaguita, from which it can be differentiated by females with ratio of length from second to fourth flagellomeres: 1.2:1.1:1.1 (versus 1.4–1.7:1.4–1.7:1.4–1.7) and lateral ocellus separated from compound eye by 0.6 times ocellar diameter (versus 1.0–1.1 times). It is the third Synosis species recorded from Brazil.
Description.Female. Fore wing length 6.1 mm.
Head. Face and clypeus 0.9 times as long as wide (Fig. 4C); malar space 1.1 times as long as basal mandibular width; lateral ocellus separated from compound eye by 0.6 times ocellar diameter; distance between lateral ocelli 1.3 times their own maximum diameter (Fig. 4E); head posteriorly behind ocellar triangle, strongly declivous and concave; gena, on lateral view 0.5 times as long as compound eyes; occipital carina absent; antenna with 29 flagellomeres, ratio of length from second to fourth flagellomeres: 1.2:1.1:1.1, subapical flagellomere 1.4 times as long as centrally wide.
Mesosoma. Mesoscutum with notaulus extending 0.7 times length of mesoscutum; scutellum flat; scutoscutellar groove scrobiculate (Fig. 4E); metapleuron bare at centre; submetapleural lobe smooth, semicircular. Propodeum with lateromedian longitudinal carinae anteriorly converging into a single carina (Fig. 4E); area basalis and superomedia without setae; area superomedia pentagonal; anterior transverse carina present between longitudinal carinae. Fore wing with vein cua distal to base of Rs&M by about 0.6 times its own length; Cu1 between 1 m-cu and Cu1a 1.5 times as long as Cu1b; Cu1a between Cu1b and 2 m-cu 1.4 times as long as Cu1 between Rs&M and 1 m-cu; 2 rs-m 0.8 times as long as abscissa of M between 2 rs-m and 2 m-cu. Hind wing with distal abscissa of M not sclerotised; Cu1 sclerotised throughout.
Metasoma. Tergite I 1.3 times as long as posteriorly wide, lateromedian carinae extending 0.4 times length of tergite without punctures present between lateromedian carina; tergite II 0.7 times as long as posteriorly wide; laterotergite II 0.2 times as long as wide (Fig. 4A).
Colour. Head (Fig. 4A, C) black except extensively yellow on face, malar space, palpi, ventral part of scape, and mandible. Mesosoma (Fig. 4D) predominantly black, except for tegula and legs (Fig. 4A) reddish testaceous except for metatibia apically brown. Wings hyaline; pterostigma brown.
Variation. The female paratype (fore wing length 5.0 mm.) varies in having: lateral ocellus separated from compound eye by 0.7 times ocellar diameter; distance between ocelli 1.4 times its own maximum diameter; antenna with 30 flagellomeres; subapical flagellomere 1.2 times as long as centrally wide; tergite II 0.6 times as long as posteriorly wide; fore wing with vein 2 rs-m 0.7 times as long as abscissa of M between 2 rs-m and 2 m-cu.
Male. Fore wing length 3.5 mm. Similar to the female except: malar space 1.2 times as long as basal mandibular width; ratio of length from second to fourth flagellomeres: 1.6:1.4:1.4; subapical flagellomere 1.4 times as long as centrally wide; tergite I 1.5 times as long as posteriorly wide, lateromedian carinae extending 0.5 times length of tergite without punctures present between lateromedian carina; tergite II 0.8 times as long as posteriorly wide; fore wing with vein cua distal to base of Rs&M by about 0.7 times its own length; Cu1 between 1 m-cu and Cu1a 1.4 times as long as Cu1b; Cu1a between Cu1b and 2 m-cu 1.45 times as long as Cu1 between Rs&M and 1 m-cu; 2 rs-m 0.6 times as long as abscissa of M between 2 rs-m and 2 m-cu.
Holotype. ♀ “Nova Teutonia 27º11′S 52º23′W BRAZIL, 300–500 m II.1966 Fritz Plaumann [CNC493232]” (CNC).
Paratypes. ♀ “Nova Teutonia 27º11′S 52º23′W BRAZIL, 300–500 m II.1966 Fritz Plaumann [CNC493233]”, metasoma dissected and storage in a glass vial and pinned with the specimen (CNC), and ♂ “Nova Teutonia Santa Catarina III.31.54 Braz [Brazil] Fritz Plaumann” (USUC).
Etymology. The species epithet zezei in reference to the main character of “My Sweet Orange Tree”, a novel by José Mauro de Vasconcelos. It is treated as a noun in apposition.
Key for New World species of Synosis

Acknowledgements
I am grateful to two anonymous reviewers for their comments and suggestions that improved the manuscript. The author was supported by a fellowship from the Fondo para la Innovación, Ciencia y Tecnología, Peru. Andrés Fabián Herrera kindly sent pictures of the holotype of S. jundiaiensis.