†Crassibethylus dominicanus sp. nov.

Maxillary palp with four articles; prosternum shorter than area of procoxa; pro- and metafemora strongly swollen, profemur lenticular-shaped, about 0.6× as wide as long; posterior margin of pronotum slightly produced backward medially; mesoscutellar groove present as a narrow sulcus; forewing vein 2Cu present; insertion of metacoxae displaced anteriorly between mesocoxal insertion; ventral carina of metasomal petiole straight.

Female. Head. Head as long as wide; antenna with 11 flagellomeres; clypeus with median clypeal carina continuous with frontal carina, lateral lobe not evident; anterior margin of frons projected anteriorly. Eye large, occupying most of lateral portion of head. Ocelli located close to vertex crest; anterior angle of ocellar triangle obtuse. Vertex straight. Mesosoma. Pronotum with dorsal pronotal area longer than mesoscutum, its posterior margin slightly produced backward medially. Mesoscutum without notaulus; parapsidal signum absent. Mesoscutellar groove as a narrow sulcus, lacking enlarged lateral pits. Metapectal-propodeal complex coriaceous; metapostnotum indistinct, apparently without metapostnotal median carina and metapostnotal-propodeal suture; posterior transverse carina present. Mesopleuron somewhat swollen in dorsal view, coriaceous, not sculptured; mesopleural pit shallow. Prosternum relatively large, somewhat rhombic-shape. Wings. Forewing with costal cell conspicuous; second radial cell closed, short, almost triangular; length of vein Rs2 as long as vein M2; length of vein Rs2+M2 as long as vein 1Rs2; stigma well developed, bula present. Legs. Pro- and metafemora strongly swollen, profemur lenticular-shaped, about 0.6× as wide as long. Insertion of metacoxae displaced anteriorly between mesocoxal insertion. Tarsal claws strongly curved, with a large basal expansion. Metasoma. Sting with 3vv narrow and long.

Figure 2. 

†Crassibethylus dominicanus gen. et sp. nov. Female holotype A dorsal habitus B lateral habitus C head and mesosoma, in dorsal view D wings and metasoma, in frontal view. Scale bars: 1 mm (A); 0.2 mm (C); 0.5 mm (D). A, B at same scale.

Figure 3. 

†Crassibethylus dominicanus gen. et sp. nov. Female holotype A head, in frontal view B mesosoma, in lateroventral view C head and mesosoma, in dorsal view D head and protórax, in lateroventral view. Scale bars: 0.5 mm (A); 0.2 mm (D). A−C at same scale.

The genus name is an allusion to the strongly swollen profemora, from Latin crassus, thick, fat, stout, and Bethylus, the type genus of Bethylinae.

Holotype female, amber inclusion from the Dominican Republic (DZUP Dom-024). Specimen complete and very well preserved. Syninclusions: one small spider and a springtail.

Holotype. Female. Body length 3.2 mm; forewing 1.95 mm long. Color. Wings clear hyaline; antenna, mandible, palpi, tegula, legs, and wing venation light castaneous; metasoma castaneous; head and mesosoma dark castaneous. Head. Head as long as wide in dorsal view, triangular-shaped in both frontal and lateral views. Mandible narrow and evenly wide along its extension. Clypeus with median lobe rounded, well projected; median carina well developed, continuous with frontal carina; lateral lobe inconspicuous. Antenna with flagellar pubescence sparse, with few outstanding erect setae; scape 3.0× longer than pedicel; pedicel as long as first flagellomere; flagellomeres subequal in length. Eye not protruding, elliptical, large, and glabrous; area between anterior margin of eye and demarcation of median clypeal lobe clearly concave. Frons coriaceous and finely punctate. Posterior ocelli close to vertex crest; anterior angle of ocellar triangle obtuse; anterior ocellus aligned with upper tangent of eyes. Vertex crest straight, sparse thick setae at corner. Hypostomal carina straight. Mesosoma. Pronotum wider than long, coriaceous and finely punctate; anterior corner angled. Metapectal-propodeal complex with lateral marginal carina. Wings. Forewing with R2 cell longer than 1Cu2 cell; only one longitudinal flexion line present, not forming rectangular area. Metasoma. About 2.3× longer than wide, polished, whole surface glabrous. Genitalia with 3vv narrow and longer than wide.

Male. unknown.

The specific epithet dominicanus is an allusion to the Dominican Republic, country from the where the amber piece originated.

Goniozus Förster is the second most speciose genus in Bethylinae, being composed by 174 described species, three of them representing fossil taxa, two from Baltic amber and one from Dominican amber (Azevedo et al. 2018). Its species are distributed around all zoogeographic regions. The taxonomic efforts for this genus are represented by a species revision for the Nearctic region (Evan, 1978), in which nine species groups were recognized; and a species revision for the Sino-Japanese region (Terayama 2006). The latest phylogenetic work for this group, published by Ramos and Azevedo (2020), included the largest representation of the diversity within Goniozus, and retrieved it as a paraphyletic group, a result also found here. Based on this result, Ramos and Azevedo (2020) reinforced the necessity to further investigate its constituent groups in order to better delimit the genus, based on the morphological evidence.

The fossil fauna of Dominican amber is interpreted here as containing two species of Goniozus. In addition to †G. respectus, described by Sorg (1988), we also transfer the taxon †Pterosclerogibba antiqua, described by Olmi (2005) as a sclerogibbid wasp, to Goniozus (see below).

Antenna, tibia, and tarsi light castaneous; head and mesosoma castaneous; metasoma dark-castaneous to nearly black. Head longer than wide, not punctured; clypeal carina strong, but not extending over frons; antenna relatively short, apical portion moniliform; malar space as long as eye length; eye small, without pilosity; ocellar triangle with a right anterior angle; vertex concave, apparently without thick setae. Mesosoma without conspicuous setae; posterior margin of dorsal pronotal area concave posteriorly; mesoscutum shorter than dorsal pronotal area, not punctured, notaulus absent; mesopleuron not gibbous; mesoscutellum as long as mesoscutum, not punctured; metapectal-propodeal complex as long as mesonotum. Forewing with clearly developed pterostigma, venation apparently reduced. Proleg with a swollen femur, almost 2.0× longer than wide, metafemora not distinctly swollen. Metasoma without visible setae; sting curved downward.

Olmi (2005) described †Pterosclerogibba antiqua as the first fully winged female of Sclerogibbidae, and postulated that this species has a great importance for evolutionary studies of the family. However, the photographs of the holotype provided in Martynova et al. (2019: 1797) and Perkovsky et al. (2020: 3) clearly indicate to us that it represents a Bethylidae. The following features, which according to Azevedo et al. (2018) are useful for the identification of bethylid wasps, can be observed in the holotype: head elongate, depressed, and prognathous; clypeus with vertical carina extending between antennae; antenna placed close to the clypeus and with 11 flagellomeres in both sexes; clypeus partially covered by antennal base; occipital carina present and complete; dorsal pronotal area always present and at least as long as wide; mesoscutum-mesoscutellar suture always represented either by sulcus or pits, or both; metapostnotum well developed and invading propodeum; propleuron covered by pronotal collar in dorsal view; mesopleural pit always present centrally or nearly so; forewing with pterostigma present and well developed. Moreover, additional features observed in the holotype of †Pterosclerogibba antiqua indicate that it belongs to Bethylinae, as follows: head triangular-shaped, in lateral profile; swollen profemur; and strongly curved tarsal claws. Although both Olmi (2005) and Martynova et al. (2019) outlined what they interpreted as the wings, these represent small cracks in the amber around the inclusion. The true wings are folded over the specimen, as can be seen in Perkovsky et al. (2020).

Within Bethylinae, Olmi’s species can be accommodated in Goniozus based on its general morphology and especially for lacking diagnostic features found in other genera of Bethylinae. Considering that Goniozus, as currently defined (see Ramos and Azevedo 2020), represents a paraphyletic assemblage, future work should focus in better positioning †Goniozus antiquus among the many species groups found within this genus.

Antenna, clypeus and legs light castaneous; head and mesosoma dark-castaneous nearly black. Head as long as wide, sparsely punctured; antenna with flagellomeres with large sensilla, distinctly moniliform; malar space shorter than eye length; eye large, without pilosity; ocellar triangle with anterior angle obtuse; vertex straight, with few scattered setae. Mesosoma setae as long as head setae; posterior margin of dorsal pronotal area concave; mesoscutum shorter than dorsal pronotal area, punctured, notaulus absent; mesoscutellum as long as mesoscutum, punctured; metanotum with metascutellum visible; metapectal-propodeal complex longer than mesonotum, lateral marginal carina of the metapectal-propodeal complex present. Forewing with clearly developed pterostigma, 1M2 cell, Rs2 vein not reach margin. Legs with profemur almost 3.0× longer than wide, metafemora not distinctly swollen. Metasoma with setae slightly longer than those on mesosoma.

The species was described by Sorg (1988) based on a single female specimen. In addition to the description, the author also illustrated the head and forewing. We were able to study this taxon based also on color photographs kindly provided by Dr. Solórzano Kraemer. As already emphasized by Sorg (1988), the wasp is preserved together with a microlepidopteran larva (see Fig. 4). Considering that all Bethylinae are known to parasitize larvae of Lepidoptera, except for the unusual Goniozus attacking Microstigmus wasps (Melo and Evans 1993), one can deduce that the larva entombed together with †Goniozus respectus likely represents its host.

Figure 4. 

†Goniozus respectus Sorg. Female holotype A dorsal habitus B view of the amber inclusions, showing the female holotype and a microlepidopteran larva (putative host). Scale bars: 0.5 mm.