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Trigonalidae Cresson 1887: 183.

Trigonalyidae Krieger 1894: 23.

Förster (1877) placed Trigonalys alone in the taxon 'Diplomorpha' which was treated equivalently to other Hymenoptera now recognised as families. Cresson (1887) was the first to use Trigonalys to form a family-rank name (Trigonalidae) but this was apparently overlooked by others. Bischoff (1938) attributed the family to Krieger (1894). Many spelling variants have been proposed (listed in Bischoff 1938 and Weinstein & Austin 1991) due to the ambiguity of the root of Trigonalys. Based on Westwood's definition of the genus Nomadina: "genus novum...Trigonalydi proximum" (Westwood, 1868) the stem of Trigonalys is Trigonalyd-, which would make Trigonalydidae the correct spelling (H.D. Cameron, pers. comm.). Since the root is ambiguous, we have used the first and most commonly used spelling, Trigonalidae.


Type genus: Orthogonalys Schulz 1905

Orthogonalys Schulz

Orthogonalys Schulz 1905: 76. Type species O. boliviana Schulz 1905 (by monotypy), repository: ZSMC. Orthogonalos Schulz 1907a (unjustified emendation).

Tapinogonalos Schulz 1907a: 14. Type species Trigonalys pulchella Cresson 1867 designated by Viereck (1914), lost (Cresson, 1916). (Syn. n.)

Satogonalos Teranishi 1931: 10. Type species S. debilis Teranishi by original designation, OMNH (Tsuneki, 1992). Synonymy by Tsuneki (1991).


Body slender, elongate; length 3.5-14.1 mm; FW 3.5-13.5 mm, most species approximately 9 mm long, FW 8 mm. Genal carina mesad of sharp genal angle, reaching or fading away before hypostomal carina; gena smooth, narrow behind eyes and generally strongly angled in ventral view; malar space generally long; antennae long, filiform, with 21-32 (most species 26-28) segments, often banded, tyloids absent; toruli close together: shortest distance between toruli less than 0.9 times the shortest distance between the inner eye margin and the torulus; wings hyaline, submarginal cell 2 often petiolate; propodeal foramen low, 'U' shaped, with wide carina; metasomal terga II & III roughly the same length (distortion of the thin plates occurs); tergum II generally with posterior medial indentation; terga mostly thin and transparent, wrapping ventrally over sterna. Aedeagus with capitate tip; parameres various, generally not much longer than wide; sterna flat, female without armature or ventral swelling and not strongly sclerotised.


Orthogonalys contrasts with most other trigonalids in several ways. Members of this genus are slender and delicate, with hyaline wings, and often banded antennae (Fig. 6). New World and African species have either their metasoma or mesosoma, or both, mostly orange, and the remainder of the body black and white. Asian species are mostly black with some white or brown markings. The outgroup analysis shows Orthogonalys is defined by primitive rather than derived characters.

Orthogonalys has a greater number of the ancestral apocritan characters than other trigonalid genera. Like the presumed primitive evaniomorph, Orthogonalys has areolate-rugose propodeal sculpturing, an elongate body form, thin metasomal terga that fold ventrally and overlap the sterna, a long malar space, and a genal carina ending near the hypostomal carina (rather than at the mandibular base). Orthogonalys cannot be assigned any unique, derived characters partly because the available outgroups are too distant to provide information about ancestral character states. Male Orthogonalys lack tyloids. The metasoma of female Orthogonalys is unsclerotised, lacks armature or traces of armature, and lacks modifications for piercing and oviposition in leaves.

Schulz (1905) described Orthogonalys as having only 5 maxillary palps, when in fact they have six. Schulz (1907a) also characterised the genus as having the metasomal terga "klaffend" or wide apart at the lateral posterior edges. However, this is a sexually dimorphic character in Orthogonalys. Females have a broad, generally flattened metasoma (Fig. 8), which is not much longer than wide, and is wider than the thorax. Schulz, deceived by the dimorphism, placed males in a different subfamily, because of their elongate, almost tubular, metasoma, which is narrower than the thorax (Fig. 7). The lightly sclerotised metasomal plates are easily distorted, which adds to the confusion.

The genus Orthogonalys includes some of the longest as well as shortest bodied Trigonalidae. Orthogonalys centrimaculta is known from a single specimen collected from northern Vietnam and is among the longest trigonalids: the body is 14.1 mm long and the forewing is 13.5 mm long. Size varies greatly within a species. One female O. formosana is 9 mm long [TARI] while another female of the same species is only 3.5 mm long [AEIC].

Because of the intra-specific variation in size and wing venation as well as the sexual dimorphism and possible abdominal distortion due to the thin metasomal plates, some of the species described from individuals or short series are probably synonymous. Orthogonalys gigantea appears to be a large O. hova. Tsuneki (1991) discussed the similarities of O. fukuiensis with O. elongata as well as the confusion caused by variation within O. elongata.

Tsuneki (1991) suggested that O. formosana, which he knew only from the holotype description, may represent an undescribed genus, while our study shows that the species shares all the features of Orthogonalys. Orthogonalys formosana is the only Orthogonalys from Asia with the following characters: hind femur and base of hind tibia amber, remainder of hind tibia dark brown; opaque white parameres (parameres of all other Trigonalidae we have seen are dark to amber); and the midline of thorax and propodeum with white spots of varying size and intensity. Orthogonalys formosana is known only from Taiwan. Orthogonalys debilis (limited to Japan) has light markings on the scutellum and dorsellum but the hind femur is dark and there are no light markings on the midline of the propodeum. A species of Lycogaster from Java has the mesonotum similarly marked but it would not be confused with Orthogonalys. While the holotype has the mandibles each with four well-developed mandibular teeth, this is not normal for the species. Symmetrical mandibles have been seen in individual O. boliviana and other species with typically asymmetrical mandibles.

Some trigonalids in other genera may appear similar to species of Orthogonalys. Taeniogonalos maga (Teranishi) resembles dark Orthogonalys but lacks the thin metasomal terga, and has tyloids. The propodeal foramen of Taeniogonalos is 'V' shaped, while in Orthogonalys it is squat and generally 'U' shaped. Afrigonalys species may also resemble Orthogonalys but has female armature and does not have banded antennae. The toruli are far apart and the SAE are less prominent in Taeniogonalos and Afrigonalys than in Orthogonalys. The SAE are generally lobed and projecting in Orthogonalys but in the North American species O. pulchella the SAE may be reduced.

We are synonymising Tapinogonalos under Orthogonalys because Viereck (1914) designated Trigonalys pulchella as the type species of Tapinogonalos and Bischoff (1938) transferred Trigonalys pulchella to Orthogonalys. Bischoff (1938), unaware of Viereck's designations, designated the unrelated Tapinogonalos maschuna Schulz as the type species of the genus. Tapinogonalos is thus a junior synonym of Orthogonalys.


There are two disjunct but closely related New World species, O. pulchella in North America (eastern United States, Mexico, and Canada) and O. boliviana in South America (Bolivia, Brazil, Argentina, Peru). In the Old World the genus is well-represented in Japan. Several Orthogonalys species known from one to a few specimens come from eastern Africa and Madagascar, north-eastern India, northern Vietnam, and Taiwan.


Smith (1996) discusses the seasonal flight activity of O. pulchella. In North America, the records of O. pulchella parasitising Nilea (=Zenillia) lobeliae (Tachinidae) in Acronicta lobeliae (Noctuidae) (Bischoff, 1909; Townes, 1956; Weinstein & Austin, 1991) are incorrect and result from taxonomic confusion. Schulz (1907a) synonymised O. pulchella with Trigonalys costalis Cresson (=Taeniogonalos gundlachii), and then reported Riley & Howard's (1891) rearing of T. gundlachii as a host record from O. pulchella. Bischoff (1938) correctly attributed this rearing record to T. costalis (=gundlachii) when he removed O. pulchella from synonymy with T. costalis. However, according to Carlson (1979) O. pulchella has been reared from Tachinidae parasitising Lepidoptera. Orthogonalys seyrigi was reared from a limacodid moth, which was presumably its intermediate host (Benoit, 1951).

Species included

Orthogonalys albomaculata Bischoff 1951. Examined male from INDIA (BMNH*).

Orthogonalys boliviana Schulz 1905. Examined from South America (44 AEIC, 3 CNCI, 5 BMNH, ZSMC*).

Orthogonalys centrimaculta Bischoff 1951. Examined male from VIETNAM (BMNH*)

Orthogonalys elongata Teranishi 1929.

=Orthogonalys hirasana Teranishi 1929 (syn. by Marsakov 1981).

=Orthogonalys debilis Teranishi 1929 (syn. by Tsuneki 1991).

Examined from JAPAN (39 AEIC, 5 CNCI).

Orthogonalys formosana Teranishi 1931. Examined 10 males, 3 females from TAIWAN (AEIC, TARI, UOPJ*).

Orthogonalys fukuiensis Tsuneki 1991.

Orthogonalys gigantea Benoit 1951.

Orthogonalys hagoromonis Teranishi 1929. Examined 127 specimens from JAPAN (AEIC, CNCI).

Orthogonalys hova Bischoff 1933. Examined 1 males, 3 females, 1? from MADAGASCAR, TANZANIA (AEIC, MRAC, NHMW, ZMUC).

Orthogonalys pulchella (Cresson 1867). Numerous specimens from eastern North America. (USNM, CNCI, AEIC, ZSMC, TAMU, CASC, FSCA, others).

Orthogonalys seyrigi Bischoff 1933. Examined 2 from TANZANIA (tentative identification, species described from Madagascar)(AEIC).


The subfamily Trigonalinae, unlike the Orthogonalinae, comprises all taxa possessing tyloids. The tribe Nomadinini, within the Trigonalinae, is assumed to have lost tyloids secondarily. Previously this subfamily was characterised by the absence of female armature (Schulz, 1907a) and included all such taxa (+ Discenea!?). According to the current analysis, female metasomal armature is not part of the groundplan for the family and has been lost repeatedly within the tribe Trigonalini. Thus the presence or absence of metasomal armature is not by itself a distinguishing character for any monophyletic group. Schulz (1905) and Bischoff (1938) attributed the Trigonalinae to Cameron (1899) who stated that he was establishing a new tribe and then gave the diagnostic features of "Trigonalidae" (?misspelling for Trigonalini) and "Nomadinae" (?misspelling for Nomadininae or Nomadinini). Apparently because of the confusion surrounding the spelling and ranking of Cameron's groups, Weinstein & Austin (1991) attributed the name to Schulz (1907a). However, since all family-group names are equivalent in status, the first used family-group name takes precedence for all family-group names (International Commission on Zoological Nomenclature, 1985, article 36a). Thus Cresson (1887), even though he never used the name Trigonalinae at the subfamily level, is the correct author of this subfamily.

Several genera in the Trigonalinae, including Pseudogonalos and Mimelogonalos, have not been included in any tribe. This approach was taken because they do not the possess the apomorphies defining the two tribes and, further, they have no characters uniting them beyond those of the subfamily. Some specimens, possibly representing undescribed genera, require additional specimens for satisfactory description and placement. A single undescribed female from Japan (Genus 1 in data matrix, Table 1, CNCI) has an unsclerotised structure that appears similar to a capsule. This specimen is close to Orthogonalys in most other respects (thin overlapping metasomal plates, genal carina ending before hypostomal carina, and hind trochantellus divided), except for a strongly areolate propodeum similar to that of Bareogonalos. A partial fusion of metasomal terga I & II is unique to this specimen. The male, and whether it has tyloids, is unknown. Because the 'capsule' is not sclerotised and the specimen does not have other derived features in common with the taxa that have capsules, we do not consider it homologous with a capsule. However, in the data matrix it has been conservatively coded as being a capsule. Two unidentified species from New Guinea (Genus 2, BPBM, AEIC, BMNH) with some primitive characteristics of Orthogonalys, such as the terga thin and folding ventrally, have broad elongate tyloids similar to, but not the same as Mimelogonalos. These taxa, as well as Teranishia are all placed in the Trigonalinae. More work on the Asian fauna is required to develop a more satisfactory understanding of the basal relationships within the Trigonalidae.

Nomadinini Cameron 1899

Type genus: Nomadina Westwood 1868


Body shape variable but never appearing slender and delicate. Antennal segments generally thickened; tyloids never present; shortest distance between toruli 1.7-2 X the shortest distance between inner eye margin and torulus; SAE is reduced and the intertorulus area is generally very flattened; genal carina reaching or ending immediately before mandibular base; metasomal plates often strongly sclerotised; female metasomal armature always present on sternum II and usually with a with a reduced armature on sternum III, sometimes under the projection of sternum II; parameres variable but generally elongate.


The genera in this tribe are characterised by the females with the primary armature ordinarily on sternum II and secondary armature on sternum III, and the males with a secondary loss of tyloids. All parasitise social wasps, except Lycogaster which parasitises both ichneumonids attacking Lepidoptera and solitary wasps (Eumeninae). Hosts are unknown for Afrigonalys and Xanthogonalos.

Bakeronymus, Nomadina, and Pseudonomadina form a distinctive monophyletic group (the old subfamily Nomadininae) (Fig. 27) having only rudimentary armature on sternum II, and their primary armature on sternum III. They also have short rounded parameres. These genera group with Bareogonalos based on their undivided hind trochantellus and symmetrical mandibles, although not all Bareogonalos have symmetrical mandibles. Bakeronymus and Pseudonomadina are sister groups sharing many complex derived features as well as having an overlapping distribution. These genera both have the vertex concave and the antenna low on the face, adjacent to the mandible. Nomadina and Pseudonomadina have rudimentary maxillary palps, but this appears to be convergent based on cladistic analysis. Another interesting, apparently convergent character is the contraction of the head posteriorly into a neck (Fig. 37) in both the Bakeronymus typicus Rohwer female from Taiwan and in Nomadina cisandina Schulz. It is not found in the B. typicus male from the Philippines or in any other Nomadina (Fig. 38).

Afrigonalys (gen. n.).

Type species: Tapinogonalos erythromelaina Benoit 1951; holotype repository, MRAC.

Diagnosis (female only)

Length: 6-9.2 mm, FW 6.7-7.4 mm. Genal carina ending at mandibular base; malar space short; gena behind base of eye swollen and extending in a transverse plane out from the genal carina; gena and vertex shiny, punctures and pubescence sparse; antennae filiform; toruli set far apart, shortest distance between inner margins of the toruli almost twice the shortest distance between the inner eye margin and the outer edge of the torulus; maxillary palps longer than mandibles; propodeal foramen 'V' shaped bordered by a narrow carina; tergum II about as long as remaining terga; armature with two parallel, sharp 'fins' on sternum II, armature on sternum III forming a flat ledge under sternum II; genitalia in flattened capsule, pointing towards armature. Male unknown.


The vertex of Afrigonalys is tall and rounded, and its surface, as well as that of the genae, is shiny and smooth. Species of Afrigonalys are black and orange with white markings. The metasoma in Afrigonalys ornatissima and Afrigonalys erythromelaina is orange except near the petiole. Afrigonalys ornatissima is white on the scutellum and the middle of the dorsellum, with extensive white markings on the head, resembling Orthogonalys seyrigi and suggesting they mimic a third wasp. The head and mesosoma of Afrigonalys erythromelaina is all black except for the mandibles and a small intra-orbital white mark. In both species the orange metasoma with thin terga, elongate shape, and shiny head create a superficial resemblance to Orthogonalys. However, Orthogonalys, has a narrower space between the toruli than Afrigonalys, and Orthogonalys females lack armature that is present in Afrigonalys. Afrigonalys also resembles Trigonalys rufiventris but it does not have the typical Trigonalys ledge between the antennae. Afrigonalys semirubra has an orange-brown head and thorax and black metasoma with ivory markings. Taeniogonalos species have a punctate, dull vertex.

Based on the phylogenetic analysis, Afrigonalys is basal to the rest of the Nomadinini. Characters uniting Afrigonalys with the Nomadinini include the flat area between the reduced SAE, intertorulus distance greater than eye to torulus distance, and the presence of female armature and capsule. Male Afrigonalys are unknown, and Afrigonalys males may, like the rest of the Nomadinini, lack tyloids. The position of Afrigonalys in the phylogenetic analysis remains unchanged even if the missing antennal character is experimentally coded as "linear tyloids present."


The name of this genus is derived from the Latin for dwellers in Africa combined with the common ending for trigonalids as originally spelled by Westwood.


This genus is only known from South Africa, Zaire, and Zimbabwe.



Species included

Afrigonalys erythromelaina (Benoit 1951). Transferred from Tapinogonalos. (comb. n.). Examined female from ZAIRE (MRAC*).

Afrigonalys ornatissima (Benoit 1950). Transferred from Tapinogonalos. (comb. n.). Examined female from ZAIRE (MRAC*).

Afrigonalys semirubra (Bischoff 1913b). Transferred from Tapinogonalos. (comb. n.). Examined female from SOUTH AFRICA (ZMHB).

Bakeronymus Rohwer

Bakeronymus Rohwer 1922: 417. Type species B. typicus Rohwer 1922 (by monotypy), repository: USNM.


Body elongate, dark reddish brown with extensive yellow markings, length 7.7-9.5 mm, FW 6.1-8 mm. Head wide, rectangular both in anterior and dorsal view, width 2.8 X length, measured from hind edge vertex to front of median ocellus, strongly cleft at vertex; entire head smooth and shining; antenna adjacent to mandible, clypeus between antennal insertions; maxillary palps very short, approximately length of mandible, four-segmented (first segment short); malar space short, at least in male; genal carina indistinct, ending at mandibular base; mandibles symmetrical, basal tooth wide, almost as wide as the 3 remaining teeth; antenna 14-15 segmented, first two flagellomeres elongate and thin, remaining flagellomeres thicker and cylindrical, not beadlike; antennal insertions wide apart, intertorulus distance is about 2.5 times the shortest distance between the inner eye margin and the torulus; wing with marginal cell darkened; two closed submarginal cells (the one female examined has part of 3rs-m cross vein); propodeal spiracle not covered; metasoma spatulate, petiole laterally slightly flattened. Parameres in side view short, 0.2 X length of basiparamere, and as wide as basiparamere; aedeagus not clearly visible, but appears elongate as in Pseudonomadina; female sternum I indented apicomedially, sternum II similarly indented but sclerotised and appearing like small bifid tooth or rudimentary armature; sternum III with prominent bifid armature projecting over smaller armature on sternum IV, and out over terminal sternum; genitalia enclosed in capsule and tip of metasoma modified into a sharp hollow awl.


The distinctive head immediately distinguishes this genus from all other Trigonalidae except the closely related Pseudonomadina. The head is shiny, transverse, with the midline at least slightly concave from the back of the vertex to the clypeus. The antennal insertions are adjacent to the mandibular base, and the clypeus is situated between the antennae. The easily visible maxillary palps that are about as long as the mandibles will distinguish this genus from Pseudonomadina, which has vestigial palps. An anterior view of the head is given in Yamane & Kojima (1982). In dorsal view the female from Taiwan has a distinct neck, as in Fig. 37, that is not found in the male from the Philippines. Unfortunately, the only specimens known are two males from the Philippines and four females from Taiwan, and the variation may be due to sexual or geographic variation, as well as species differences (Yamane & Terayama, 1983).


Bakeronymus has been collected in the Philippines and Taiwan.


The genus was reared in Taiwan from Parapolybia varia Fabricius (Polistini, Vespidae) (Yamane & Terayama, 1983).

Species included

Bakeronymus typicus Rohwer 1922. Examined males, female from PHILIPPINES, TAIWAN (USNM*, YAMA).

Bareogonalos Schulz

Bareogonalos Schulz 1907a: 18. Type species Trigonalys canadensis Harrington 1896, designated by Schulz (1907b) nec Viereck (1914). Repository: ZMHB, see Carmean, 1989.

Nippogonalos Uchida 1929: 79. Type species N. jezoensis Uchida 1929 by monotypy, repository: EIHU (Yamane, 1973).


Mesosoma and metasoma stout and thick; body length: 8.3-13+ mm (forewing 7.5-13.1 mm); head small and rectangular, with long pubescence; malar space long; genal carina obsolescent near hypostomal carina; antenna 18-23 segmented; intertorulus distance variable, usually about equal to torulus to inner eye distance, half as wide in B. huisuni and an undescribed species from Sumatra; mandibles symmetrical (except in B. jezoensis); scutellum raised; hind trochantellus undivided; thorax and propodeum coarsely areolate, contrasting with smooth, generally shining metasoma; terga transparent at sides; metasoma sexually dimorphic, in female almost as high as wide, semi-rectangular and blunt posteriorly in dorsal view, in male elongate fusiform, pointed posteriorly; paramere is short and wide, forming right angle to basiparamere, width 3.3 X length and 1.3 X width basiparamere; aedeagus laterally flattened, expanded at tip into symmetrical club or 'T', width 3.6 X width of base, each side of 'T' about the same height as width of base. Female primary armature on sternum II, projects over sternum III which has a similarly shaped though slightly smaller armature; genitalia held in capsule.


The species of Bareogonalos form a monophyletic group united by their parasitism of vespines, and by their dorsally transverse heads with long pubescence, generally stout shape, sexual dimorphism, deeply areolate propodeum and smooth, often shining metasoma. The female metasoma is almost as high as it is wide with the main armature on sternum II. Bareogonalos has the hind trochantellus undivided and maxillary palps as long or longer than the mandibles. The antennal insertions are above the clypeus, remote from the mandibular base. Other genera with the hind trochantellus undivided have relatively slender metasomas with the main armature on sternum III. These other genera also have greatly modified heads including vestigial palps and/or antennal insertions at the level of the mandibular base with the clypeus between the insertions.

Koenigsmann (1976), apparently based on Schulz (1907a), stated that Bareogonalos females characteristically have one more antennal segment than the males. However, the number of flagellomeres depends primarily on the size of the individual, and thus the host size (Carmean, 1988; Yamane & Yamane, 1975).


Species of Bareogonalos are found around the perimeter of the Pacific including SW Mexico, NW United States and SW Canada, E Siberia, Japan, Taiwan, and Indonesia (Java and Sumatra).


Bareogonalos species are the only confirmed trigonalid parasitoids of Vespinae (Vespidae), including Dolichovespula, Vespa, and Vespula (Carmean, 1988, 1991; Carmean et al., 1981; Ono, 1987, 1988; Stage & Slobodchikoff, 1962; Vecht, 1934; Yamane, 1973; Yamane & Yamane, 1975). In addition, an undescribed species from Indonesia was reared from Provespa (YAMA).

Bareogonalos canadensis larvae initially feed internally and then emerge to feed externally and pupate under a thickened cap (Figs 31-32).

Species included

Bareogonalos canadensis (Harrington 1896). Examined numerous specimens from CANADA and USA (CARM, CASC, CNCI, USNM, ZMHB*).

Bareogonalos huisuni Sk. & S. Yamane 1975. Examined 1 female, 1? from TAIWAN (YAMA).

Bareogonalos jezoensis(Uchida 1929). Examined 3 males, 4 females, from INDONESIA and JAPAN (ZMHB, MCZC, USNM, CARM).

Bareogonalos scutellaris (Cameron 1897). Examined holotype male, and holotype female of Trigonalys flavonotata Cameron 1897, from MEXICO (BMNH*).

Undescribed Bareogonalos sp. from INDONESIA, male, females (YAMA).

Lycogaster Shuckard

Lycogaster Shuckard 1841: 121. Type species L. pullata Shuckard 1841 (by monotypy), repository: lost.


Body stout, length 5.5-13 mm, FW 4.8-11.2 mm (most 9-10 mm long, FW 8.5 mm). Genal carina meeting lateral edge of mandibular base in Asian species and hypostomal carina in New World species; malar space short; antenna spindleform or thickened, with 22-24 segments, lacking tyloids; shortest distance between toruli 1.7-2 X the shortest distance between inner eye margin and torulus; anterior tentorial pits large; clypeal suture (=epistomal suture) indistinct; forewing with submarginal cell II ordinarily not petiolate; entire forewing smoky (not dark); tergum I relatively broad; tergum II about as long as following terga together. Paramere making almost a forty-five degree angle to basiparamere, and short and wide (2.7 X wider than tall); basiparamere 1.7 X longer than wide; aedeagus laterally flattened, tip drawn out to a dorsal point, height of tip 1.25 X the height of shaft; anterior transverse groove on sterna III & IV of male; female sternum II with high posterior ledge, central projection distinct in New World species and slight in Asian species, sternum III with anterior ledge, often under ledge of sternum II.


Lycogaster can be identified by the stout, usually punctate body, and the short spindleform antenna with the flagellomeres cylindrical rather than knobbed as in Bareogonalos. The second metasomal segment is longer than the following segments which are slightly attenuated and in the female, strongly curved ventrally and anteriorly. The female armature is composed of a ledge on the second sternum which does not project posteriorly over the following segments. Lycogaster may be most closely related to the neotropical genus Seminota. However, Seminota species have shiny heads with long, posteriorly angulate vertices, while those of Lycogaster have punctate heads with rounded vertices.

Asian Lycogaster species group together due to the armature of the female having slightly uplifted prongs on either side, and the male with two lateral subapical prongs on sternum II. However, these modifications could be derived features within Lycogaster, and there is otherwise not sufficient evidence to warrant dividing the Asian species from the North American species as a new genus. We have not seen the male antenna of any Asian species, but Chen (1949) described L. violaceipennis as lacking tyloids.

Bischoff's concept of Lycogaster was very broad, as he included a species with tyloids, Lycogaster zimmeri Bischoff, which we have transferred to Taeniogonalos, and a species with filiform antennae, Lycogaster semibrunnea Bischoff, which Riek (1954) transferred to Taeniogonalos.


Lycogaster pullata is known from North America (Mexico, United States and Canada) and L. apicipennis is known from Central America (Mexico and Costa Rica). The other species are from eastern Asia (Indonesia, China, Burma).


North American species have been reared from Ichneumonidae parasitising Saturniidae (Lepidoptera) (Bischoff, 1909), from Eumeninae, Vespidae (Hymenoptera) (Cooper, 1954; Parker & Bohart, 1966) and Arctiidae (Lepidoptera) (intermediate host) [LACM], (Townes, 1956). D.H. Janzen (pers. comm.) has reared L. apicipennis from Enicospilus (Ichneumonidae, Hymenoptera) parasitising Notodontidae (Lepidoptera).

Species included

Lycogaster apicipennis (Cameron 1897). Specimens examined, COSTA RICA, 122 (EMUS, INBIO, RMNH, NHMW); MEXICO, 2 females (LACM, NHMW).

Lycogaster celebesiensis (Szepligeti 1902). Type material examined: female, desig. lectotype n., to formally recognise the unpublished designation by J. Papp; INDONESIA: S. Celebes, Bua-Kraeng, 5000 ft, ii.1896 (H. Fruhstorfer) (HNHM). Condition, left wings broken off and glued to card (det. as male by Szepl.). Also examined male, 3 females from INDONESIA, CHINA (RMNH, CASC).

Lycogaster heinrichi Bischoff 1933.

Lycogaster pullata Shuckard 1841. 74 specimens from UNITED STATES, CANADA, and MEXICO: 42 EMUS, ZSMC, UMMZ, MCZC, AMNH, UCDC, CNCI and others.

Lycogaster violaceipennis Chen 1949. Examined female from CHINA (ZMHB).

Undetermined Lycogaster sp., 5 females from INDONESIA, MALAYSIA, (FSAG, ANIC, USNM).

Nomadina Westwood

Nomadina Westwood 1868: 328. Type species N. smithii Westwood (by monotypy), repository: BMNH.

Liaba Cameron 1899: 3. Type species L. balteata Cameron 1899 (by monotypy), repository: BMNH.

Platygonalys Schulz 1905: 86. Type species P. phylogenetica Schulz 1905 (by monotypy), repository: ZMHB?.


Length: 5.5-11 mm, FW 4.6-10.5 mm. Antennae thickened, 16-segmented; intertorulus distance about 1.2-1.9 X torulus to inner eye distance; maxillary palps rudimentary; clypeal suture below the antennal insertions; clypeus longer than wide, projecting over the base of mandibles; head relatively smooth and shiny, covered with dense short pubescence; mesosoma very smooth; FW with one closed submarginal cell (two in N. smithii); mesothoracic and propodeal spiracles uncovered; propodeal foramen broadly 'U' shaped, wider than tall; metasoma dorsoventrally flattened, terga and sterna very thin. Parameres rounded, 2 X wider than tall but not angled or extending past basiparamere; aedeagus expanded apically, making a 'V' perpendicular to the shaft and pointing anteriorly, shaft quite stout; female sternum II sclerotised apicomedially, armature appearing vestigial; main armature on sternum III, generally projecting over sternum IV and reaching the terminal sterna; genitalia contained in elongate flattened capsule with prominent sclerotised 'awl' pointing anteriorly.


Nomadina is the only genus with 16 antennal segments, and may be the only genus in which the antennal segment number does not vary with size. The mesothoracic and propodeal spiracles of Nomadina (as well as Bakeronymus and Pseudonomadina) are uncovered while other trigonalid genera have their mesothoracic spiracle covered by a pronotal lobe.

Nomadina and Pseudonomadina differ in some aspects of their male genitalia-- the basiparameres (large and stout) and parameres (reduced) are similar, but the aedeagus of the Nomadina is clubbed, while it is asymmetrical and knife shaped in Pseudonomadina. Xanthogonalos has parameres that are narrowly transverse, but the aedeagus is clubbed as in Nomadina.


This genus is neotropical, occurring in Costa Rica, Panama, Venezuela, Ecuador, and Brazil. Although N. balteata is described from Chile, all known collections are from Venezuela and Ecuador. The type locality, 'Chili', is probably an error.


Nomadina have been reared from colonies of Polybia and Agelaia (Polistini, Vespidae)(BMNH). Sean O'Donnell (pers. comm.) observed Nomadina smithii acting as a Wasmannian mimic of small workers in a colony of Agelaia xanthopus (Vespidae) it was reared from.

Species included

Nomadina balteata (Cameron 1899).

=Nomadina nasuta Bischoff 1933. Syn. n.

Examined 2 males, 3 females, "Chili"?; ECUADOR, VENEZUELA (BMNH*, AEIC, IZAV).

Nomadina cisandina (Schulz 1905). Examined 7 females, BRAZIL (BMNH, MCZC).

Nomadina phylogenetica (Schulz 1905).

Nomadina smithii Westwood 1868. Examined 1 male, 3 females, 'Amaz.', COSTA RICA (BMNH*, CARM, UMMZ).

Pseudonomadina Yamane & Kojima

Pseudonomadina Yamane & Kojima 1982: 183. Type species P. biceps Yamane & Kojima (by monotypy).


Length 6 mm; FW in female 5.5 mm; male FW unusually short, 3.8 mm. Head wide, almost 5 X as wide as long (length measured from hind edge to front of median ocellus), rectangular when viewed from above, strongly cleft at vertex; head, including vertex and frons, smooth and shining; eye small compared to eye in Bakeronymus; antennae 13-14 segmented, each flagellomere conical, expanded apically; torulus adjacent to mandible, clypeus located between toruli, intertorulus distance about twice inner eye to outer torulus distance; maxillary palps rudimentary, 4-segmented, although segments sometimes indistinct; malar space long, receiving antenna; mandibles symmetrical, basal tooth wide, almost as wide as 3 remaining teeth; the hind trochantellus undivided; legs stout in male and slender in female; marginal cell slightly darkened; number of submarginal cells may be a variable character as male has incomplete 2 and 3rs-m cross veins; wings projecting past abdomen at rest in female but not in male; propodeal spiracle not covered; petiole only slightly laterally flattened; parameres (as exposed in side view) short, 0.25 X as long as wide, same width as basiparamere; basiparamere twice as long as wide; aedeagus laterally flattened, not expanded apically; female sternum II with small bifid tooth or rudimentary armature; sternum III with prominent bifid armature, projecting over inconspicuous armature on sternum IV and over terminal sternum; genitalia enclosed in capsule formed by flattened sternum VI and the tip modified into a sharp hollow awl set in sternum V.


Pseudonomadina has the general appearance of a small bee with a greatly modified head. Pseudonomadina is the only trigonalid in which the width of the head exceeds the length of the mesosoma. The midline of the head is strongly cleft, and each side is slightly bulbous, giving it the appearance of parts of two heads joined at the center. The antenna is 14-segmented in the male and 13-segmented in the female, and the flagellomeres are conical, with each flagellomere coming from the center of the preceding. These characteristics, plus the vestigial maxillary palps, will distinguish this genus from all others. Pseudonomadina is similar to Bakeronymus and Nomadina in many characteristics as described above.

Biology and Distribution

This species was found in two of eight nests of Ropalidia (Icarielia) flavobrunnea (Polistini, Vespidae), from a total of about 100 nests examined in a study of Philippine Ropalidia (Yamane & Kojima, 1982). It is only known from these two rearings.

Species included

Pseudonomadina biceps Yamane & Kojima 1982. Examined paratype male, female, PHILIPPINES (USNM, RMNH). Holotype repository EIHU.

Seminota Spinola

Seminota Spinola 1840, p.6, pl. 41. Type species S. leprieurii Spinola (by monotypy).

Bertonia Schrottky 1906: 349. Type species B. nigra Schrottky (by monotypy), repository: lost. Synonymy by Schulz (1906c).


Body stout; head shining, rest of body except petiole punctate, dull; all black, except one species usually with small yellow spots on petiole; wings with black markings; length: 7 mm-15 mm; FW 6.5-12.5 mm. Genal carina meeting hypostomal carina, except genal and occipital carina absent in S. depressa; malar space long; vertex sharply angled behind ocelli toward top of occipital carina, or where it would be in S. depressa; clypeal suture indicated by indistinct line; suture between the anterior tentorial pits below antennae forming an upside down 'V' with a noticeable bump or pit, (much smaller than an ocellus) at the apex at about the level of the top of the torulus, similar bump above each antenna; antennae spindleform, 21-24 segments; toruli far apart, shortest distance between toruli 2-4 times shortest distance between inner eye margin and torulus; mandibles asymmetrical (one individual of S. marginata in a reared series of six (BMNH) with mandibles symmetrical); propodeum with deep medial groove; tergum II about as long as following terga together. Paramere about as wide as long, dorsally squared and ventrally rounded; male sterna III & IV with transverse grooves; female with armature on sternum II.


Seminota is a distinctive genus. The species are stout and all black, except for S. depressa which usually has two light marks near the posterior margin of tergum I. The head is smooth and shining, although pubescent, and has a long flattened vertex which is angulate posteriorly just above the middle of the occipital carina. The antennae are strongly spindle-form. Seminota is probably closest to Lycogaster, but can be easily distinguished by the punctate head of Lycogaster which contrasts with the smooth, shiny head of Seminota.

The holotype of the type species, S. leprieurii, is missing the metasoma but differs from other Seminota in its wing markings. The illustration and description of the holotype (Spinola, 1840) and the damaged holotype have the main characters of the genus but not the specific metasomal characters we have used. It appears allied to, and possibly the same as S. marginata.

Schulz states that S. inquirenda is very similar to S. marginata but smaller, with finer and more sporadic punctures, and a third submarginal cell that is decidedly shorter than the second. These characters vary intraspecifically in other Trigonalidae and do not justify maintenance of two separate species names. Thus we are synonymising S. inquirenda with S. marginata.


Seminota is only known from the neotropics (Mexico, Costa Rica, Panama, Brazil, and Argentina).


Seminota species have been reared from Polistini (Vespidae) including Apoica (BMNH), Mischocyttarus (BMNH, IMLA), Parachartergus (CARM), Polistes, and Pseudopolybia (Weinstein & Austin, 1991).

Species included

Seminota depressa (De Geer 1773). Examined 5 males, 10 females, 1?(holotype) from BRAZIL, BOLIVIA, PERU, COSTA RICA (BMNH, IMLA, NHMW, OSUO, AMNH, ZMHB, OXUM, NHRS*).

Seminota laeviceps (Cresson 1879). Examined 2 males, 7 females, 'Mex', COSTA RICA, PANAMA (KIMS, MCZC, ANSP*).

Seminota leprieurii Spinola 1840. Nec leprieuri Spinola of Schulz, 1907a; Bischoff, 1938; and Weinstein & Austin, 1991. Examined 1? (metasoma missing), FRENCH GUIANA (MRSN*).

Seminota marginata (Westwood 1874).

=Seminota inquirenda Schulz 1907b. Holotype repository: MLUH? (syn. n.)

=Seminota taschenbergi Schulz 1906b. Holotype repository: MLUH (M. Dorn, pers. comm.).

Examined holotype S. marginata, female, and 9 males, 23 females from BRAZIL, ARGENTINA, VENEZUELA, PARAGUAY, COLOMBIA (USNM, UCDC, NHMW, CASC, MCZC, BMNH*, ANSP, IZAV, IMLA, AEIC, USNM, ZMHB, MLPA).

Seminota mexicana (Cresson 1879). Examined paratype male (ANSP) and male, 7 females, MEXICO (EMUS, UCDC, LACM, CNCI).

Unplaced specimens: female, possibly S. laeviceps:, MEXICO (ZMHB); female, asymmetrical petiole, protruding clypeus, VENEZUELA (BMNH).

Xanthogonalos Schulz

Xanthogonalos Schulz 1907a:17. Type species X. robertibuyssoni Schulz 1938 designated by Viereck (1914). Holotype repository MNHN, but loaned to Schulz and not returned according to notes of Berland (J. Casevitz-Weulersse, pers. comm.).


Body elongate, smooth, with dense short erect pubescence; Length 9.4-10.2 mm, FW 9.0-9.3 mm. Head transverse in anterior view (especially in male); frons and vertex forming a flat sloping plane from the antennae to back of head; eyes with sparse pubescence; genal carina extending straight towards edge of mandibular base, sometimes obsolescent near end; no genal angle between genal carina and base of eye; prominent suture above each antenna ending in a small round bump; intertorulus distance and torulus to eye distance about equal; submarginal cell III square, about one third the length of the long, narrow submarginal cell II; propodeal foramen 'U' shaped. Parameres and aedeagus very similar to Nomadina; aedeagal shaft laterally flattened, 0.3 X width paramere; female sternum II with thin medioapical projection overlapping sterna III & IV; sternum III with small medioapical projection.


Xanthogonalos is the only trigonalid genus with pubescent eyes. This pubescence consists of short, erect, sparse bristles distinctly visible at magnification of X30 although some specimens may require searching for the right angle that highlights an area with hairs. Other characters are more difficult to use for diagnosis and too few specimens are available to distinguish among interspecific, sex specific, and intraspecific differences. Xanthogonalos is characterised by an elongate shape, females with strongly projecting armature on an elongate sternum II, and the males lack tyloids. In the male, sternum II is only slightly longer than sternum III. In most trigonalids the back of the eye is even with the middle of the mandibular base, while in the South American specimens of Xanthogonalos the posterior margin of the eye is behind or parallel to the mandibular base (Figs 33, 34). Females have a long malar space while males have a short malar space resulting from having a larger eye. All specimens are covered by short pubescence. In undescribed species #1, the pubescence is very dense and short, giving the body a plush appearance.

Xanthogonalos fits well within the Nomadinini, due to its armature and lack of tyloids. Schulz (1907a) placed the genus with Seminota, probably due to the angulate vertex and elongate submarginal cells, but the male genitalia is more similar to Nomadina, not Seminota.

The generic description in Schulz (1907a) appears to be of a composite of Xanthogonalos and Trigonalys. Schulz (1907a) described Xanthogonalos from three specimens: Xanthogonalos robertibuyssoni, the type species, from a single female from Mexico, and X. severini from two males with tyloids from "South America". We have identified two males without tyloids as representing an undescribed species of Xanthogonalos: they share the pubescent eyes and other characters of Xanthogonalos. The species severini does not belong to Xanthogonalos since presence or absence of tyloids does not vary intra-generically. Xanthogonalos species are superficially similar in colouration and elongate shape to the xanthic forms of the unrelated South American Trigonalys sanctaecatharinae (Schulz). We are synonymising X. severini and X. fasciatus Bertoni with T. sanctaecatharinae.





Species included

Xanthogonalos robertibuyssoni Schulz 1907a. Examined female, COSTA RICA (BMNH).

Undescribed species #1: 2 females, VENEZUELA, ARGENTINA (IMLA).

Undescribed species #2: 2 males, COLOMBIA (BMNH).

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