Genus Calligaster de Saussure
Calligaster de Saussure, 1852: 22. Type species: Calligaster cyanoptera de Saussure, 1852, by subsequent designation of Ashmead (1902: 205).
Diagnosis.
The genus Calligaster can be differentiated from any other eumenine genera by the combination of the following characters: labial and maxillary palpus with three and six palpomeres respectively; mid tibia with two spurs; mesepisternum with horizontal suture absent; propodeum with propodeal orifice rounded dorsally, apical valvula short and rounded, and submarginal carina not projecting as pointed lobe above valvula; metasomal segment I petiolate; tergum I in dorsal view abruptly widened laterally shortly after basal slit, then nearly parallel-sided apically, with longitudinal striae; metasomal sternum II with basal fossa; male characters: terminal antennal flagellomere simple; distal lobe of gonocoxite sub-truncated; gonostyle subapically with a tuft of short and thin hairs; basivolsella long and narrow, slightly enlarged at the base, with an obliquely truncated apex.
Remarks.
Calligaster was proposed by de Saussure (1852: 23, Pl. IX fig. 6) as a genus to accomodate his two species from “Java”: Calligaster cyanoptera de Saussure, 1852 and C. hero de Saussure, 1852. Later, he (de Saussure 1855: 115) synonymized C. hero under Zethus gigas Spinola, 1841, which is a South American Zethus species and is now treated as a synonym of Zethus coeruleopennis (Fabricius, 1798) (Bohart and Stange 1965). Although de Saussure (1855) did not refer to the type locality of C. hero given in de Saussure (1852) (= “Java”), it may have been certainly based on an erroneous labeling. Ashmead (1902) designated C. cyanoptera de Saussure as the type species of Calligaster de Saussure, 1852.
The taxonomic status of Calligaster had not been stabilized until Bequaert (1928) reinstalled its generic status; that is, de Saussure (1855) treated it as a division in the genus Zethus; Gribodo (1892), possibly having followed de Saussure (1855), treated Calligaster as a subgenus in the genus Zethus when he described Zethus javanus (= C. cyanopterus); Dalla Torre (1904) treated Calligaster as a genus; and Cameron (1904, 1909) described two species of Zethus, which Bequaert (1928) transferred to the genus Calligaster . But, establishment of the concept of Calligaster currently accepted by most of the vespid taxonomists was of Giordani Soika (1960).
Key to species of Calligaster
As no specimens were available to us, the characters for C. etchellsii and C. zetteli were extracted from Cameron (1909) and Bequaert (1928), and Gusenleitner (2006), respectively. Neither information of the male characters of C. zetelli nor of the female of C. etchellsi is available to us. In Calligaster, we have observed distinct morphological differences between sexes in the head characters, while characters of the mesosoma and metasoma (except for the number of metasomal segments and genital organs) are nearly the same between the sexes. In the following key, sex is specified only for the head characters.
| 1 | Metasomal tergum I other than basal petiolate part in lateral view hardly convex dorsally (Fig. 4) | 2 |
| - | Metasomal tergum I other than basal petiolate part in lateral view more or less distinctly convex dorsally (Figs 1, 3, 5) | 3 |
| 2 | Female clypeus with dense and coarse punctures. Propodeum with dorsal face smooth and barely punctured. Metasomal tergum II basally barely punctured, apically with sparse minute punctures. Female mandible entirely black | C. williamsi Bequaert |
| - | Female clypeus with sparse minute punctures. Propodeum with dorsal face coarsely punctured. Metasomal tergum II entirely with sparse minute punctures. Female mandible with yellow basal spot | C. zetelli Gusenleitner [male unknown] |
| 3 | Male clypeus in frontal view about 1.5 times as wide as high. Body black entirely or with bright yellow markings | 4 |
| - | Male clypeus in frontal view about 2 times as wide as high; ventral margin shallowly emarginate medially. Body with pale-yellow markings | C. etchellsii (Cameron) [female unknown] |
| 4 | Metasomal tergum I in lateral view without distinct subapical depression (Fig. 1); in dorsal view strongly convex along lateral margin (Fig. 6). Wings fuscous, with greenish-purple iridescence | C. viridipennis Giordani Soika |
| - | Metasomal tergum I in lateral view distinctly constricted subapically (Figs 3, 5); in dorsal view nearly parallel-sided, with slight subapical constriction (Figs 7, 9). Wings fuscous, with blue-green and purple iridescence | 5 |
| 5 | Metasomal segment I in dorsal view relatively slender, about 2.5 times as long as its maximum width (Fig. 7); tergum I hardly punctured, so that dorsal striae are more or less conspicuous | C. cyanoptera de Saussure |
| - | Metasomal segment I in dorsal view shorter and stouter, about 1.8 times as long as its maximum width (Fig. 9); tergum I with dense and distinct puncture, so that dorsal striae inconspicuous | C. himalayanensis (Cameron) |