Baeosega Krombein, 1983

Mita, Toshiharu, 2021, Taxonomic study of Baeosega and its allies, with description of a new species of Nipponosega (Hymenoptera, Chrysididae, Amiseginae), ZooKeys 1041, pp. 1-25 : 1

Genus Baeosega Krombein

Baeosega Krombein, 1983. Type species: Baeosega torrida Krombein, 1983, original designation.

Diagnosis.

The female of Baeosega is superficially similar to Nipponosega and Okinawasega . However, the occipital carina is developed and reaching lower gena in Nipponosega (absent in Baeosega ) and the deep malar sulcus is present in Okinawasega (only faintly indicated in Baeosega ). The male is very similar to Okinawasega . The longer setae on flagellum and remarkably long R1 of the forewing are useful characters distinguishing Okinawasega from Baeosega. Compared to the above two genera, the male of Nipponosega has the pronotum short. The pronotum of Baeosega and Okinawasega is as long as or longer than mesoscutum but it is shorter in Nipponosega . Compared to genera found in South Asia, Baeosega is most similar to Serendibula . In the female of Baeosega , the metasomal T2 is lacking fine longitudinal carinae whereas T2 of Serendibula is covered with fine carinae. The male of Baeosega can be distinguished from Serendibula by having longer setae on antennal flagellomeres, the shorter metanotum, almost half as long as mesoscutellum (metanotum is longer, almost as long as mesoscutellum in Serendibula ) and the tubular distal apex of pterostigma (very sharp in Serendibula ). The inner tooth of tarsal claw is minute and indistinct in both female and male of Baeosega , whereas the inner tooth is distinctively large in Serendibula .

Description.

Female. Clypeal apex not thickened; malar sulcus absent or indicated as faint track; scapal basin shallow, cross-ridged, median longitudinal carina absent; occipital carina absent, at most posterior margin of vertex forming corner behind ocellar triangle; eye setose; flagellum fusiform, intermediate segments broader than long, and with ventral surface flattened. Mesosoma slender, dorsum more or less punctate; pronotum with median groove and shallow pit before lateral lobe, 1.0-1.4 × as long as combined length of mesoscutum, mesoscutellum and metanotum; mesoscutum with notauli; parapsides lacking; posterolateral corner of mesoscutum not lobate; micropterous (Fig. 1A, B ), forewing pads extending to posterior margin of mesoscutellum; mesopleuron with omaulus, without scrobal sulcus; metanotum triangular and small, ca. 2/3 as long as mesoscutellum; propodeum with long dorsal surface and a pair of recumbent teeth present, meeting or almost meeting together, dorsal posterolateral angles bluntly angulate, lateral and posterior surfaces abruptly declivous. Hind coxa with dorsobasal carina; tarsal claws with a minute inner tooth. Metasoma smooth, shagreened or weakly granulated, without longitudinally striate area.

Male. Clypeal apex not thickened; scapal basin flat or weakly excavated, cross-ridged; malar sulcus present; occipital carina absent; eye setose; antenna elongate, F3 2.7-3.5 × longer than wide. Mesosoma slender, dorsum densely punctate; pronotum with median groove and shallow pit before lateral lobe, slightly longer than mesoscutum, 0.5-0.6 × as long as combined length of mesoscutum, mesoscutellum and metanotum; mesoscutum with notauli; parapsidal line faintly indicated; mesopleuron without omaulus and scrobal sulcus; metanotum approximately half mesoscutellum; a pair of recumbent teeth present, meeting or almost meeting together; propodeum with dorsal posterolateral angles bluntly angulate, posterior surface abruptly declivous; fully winged (Fig. 1C ), pterostigma thin; R1 not indicated, distal apex tubular; Rs extended by weakly curved dark streak; medial vein arising before cu-a. Hind coxa with dorsobasal carina; tarsal claws with a minute inner tooth. Metasoma sparsely punctate with smooth interspaces.

Distribution.

Oriental region: Sri Lanka.

Hosts.

Unknown.

Remarks.

According to Krombein (1983), the female of Baeosega has no malar groove. However, a trace of a groove is present from the lower margin of the eye to the mandibular base. A minute inner tooth is also present in the claws of both female and male, but the size of tooth is remarkably small compared to Serendibula .

Figures

Figure 1. General habitus of Amiseginae A Baeosega humida Krombein, holotype ♀ B B. torrida Krombein, holotype ♀ C ditto, allotype ♂ D Nipponosega lineata sp. nov., holotype ♀. Scale bars: 1.0 mm.