Parapolybia takasagona Sonan 1944

Kojima, Jun-Ichi, Saito, Fuki & Nguyen, Lien Thi Phuong, 2011, On the species-group taxa of Taiwanese social wasps (Hymenoptera: Vespidae) described and / or treated by J. Sonan, Zootaxa 2920, pp. 42-64 : 52

Parapolybia takasagona Sonan 1944 [ Parapolybia takasagona Sonan 1944 ]

Among Sonan's social wasp taxa, this one needs special attention to discuss its taxonomic status. Our conclusion, as outlined below, treating Parapolybia takasagona as a valid species is tentative. In order to establish a well corroborated species-level taxonomic system of the Parapolybia indica group, to which P. takasagona belongs, further intensive studies that covers various “populations” are required.

Sonan (1944) recognized four nominal species in Parapolybia occurring in the territories of the Japanese Empire of that time. They were: P. v a r i a ( Fabricius 1787), which Sonan considered to occur in Taiwan and main islands of Japan; P. disticha (du Buysson 1913) [currently treated as a synonym of P. v a r i a (van der Vecht 1966), although its taxonomic status needs further careful examination (F. Saito, unpublished)], which Sonan considered to occur in the Korean Peninsular; P. indica (de Saussure 1854) in Japan; and P. takasagona . Sonan (1944) described P. takasagona based on the holotype Ƥ collected at Tamaru in Rato District, and 6 Ƥ and 6 3 paratypes. In TARI, there are the holotype and 6 Ƥ and 5 3 paratypes; Sonan (1944) mentioned 3 3 from “Kobayashi, Rato”, but one of them was not located.

Type material. Holotype Ƥ: “Tamaru (Rato) / 30 VIII 1923 / Col. J. Sonan”, Type label, “ Parapolybia / takasagona / Sonan / Det. J. Sonan” and “78”, is hardly considered to be discolored in contrast to Starr's (1992) and Yamane et al. 's (1995), and it well matched the original description ( Sonan 1944). The labels of collection data for female paratypes are as follows: 2 Ƥ, “Tabo (Rato) / 24 VIII 1923 [1 Ƥ: 22 VIII 1923] / Col. J. Sonan”; 1 Ƥ, “Kobayashi / (Rato) 29 VIII 1923 / Col. J. Sonan”; 1 Ƥ with “Arisan / 2.V.1917 / Col. T. Shiraki”; and 2 Ƥ, “Taiheizan / FORMOSA / Jul.1930 / S. Minowa”. The two female paratypes from “Tabo” have the occipital carina evanescent ventrally and certainly belong to a species different from that to which the holotype belongs. One of the two female paratypes from “Taiheizan” has yellow markings brighter and more abundant than the holotype and the specimen may possibly belong to a different species. The condition and the label data for the five male paratypes are as follows: 3 3 (1 3: second to terminal flagellomeres of the right antenna and fourth to terminal flagellomeres of the left antenna missing; 1 3: metasoma except the first segment, fourth to terminal flagellomeres of the right antenna and fifth to terminal flagellomeres of left antenna, missing [Sonan may have used this male for genital observation]), labeled “Kobayashi / (Rato) 28 VIII 1923 / Col. J. Sonan”; 1 3 (third to terminal flagellomeres of both antennae missing), labeled “Taiheizan / 26 VIII 1923 / Col. J. Sonan”; and 1 3 with a label of “Taiheizan / 25 VIII 1923 / Col. J. Sonan”.

Starr (1992) examined these type specimens in TARI and concluded that P. takasagona is a valid species, differing from P. v a r i a ( Fabricius 1787). He treated P. takasagona as the senior sysnonym of P. nodosa van der Vecht, 1966, which was described based on the holotype Ƥ collected at Pilam [= Beinan, ca. 22°45' N, 121°01' E] in Taiwan and the female paratypes from four other localities in Taiwan, and Burma (Tenasserim), China (Fukien), India (Umbaso) and Thailand. However, Starr (1992) referred neither to the conditions of female occipital carinae in type specimens of P. takasagona nor to that given in the original description of P. nodosa . That is, the female occpital carina is complete in the holotype of P. takasagona while it is obliterated ventrally in P. nodosa (van der Vecht 1966: 23).

Yamane et al. (1995) examined the holotype of P. takasagona and concluded that P. takasagona was a junior synonym of P. i n d i c a (de Saussure 1854) because “The holotype specimen [of P. takasagona ] has complete occipital carina on gena, which is the most reliable characteristic that constantly separates P. i n d i c a from the other Oriental congeners [P. v a r i a and P. nodosa ].” Another reason for their synonymy was that “the occurrence of P. i n d i c a in Taiwan has been strongly suggested by a female specimen collected by Dr. Kenji Ohara near Hsitsun, Taoyuan (1000–1200 m alt.) and three female specimens housed in the Department of Zoology, Taiwan Museum (Taipei).” They also mentioned that “the structural characteristics [of the holotype of P. takasagona ] well agree with those [= structural characteristics of P. i n d i c a] mentioned by Vecht (1966).” However, the female structural characteristics that van der Vecht (1966) mentioned are only “Occipital carina complete, extending to the base of the mandibles. Length (h. + th. + t.1 + 2): 14–17 mm, rarely only 13 mm ” (p. 23). Yamane et al. (1995) referred to the color pattern of the holotype of P. takasagona that it is “in accordance with that of P. i n d i c a ”, but they did not mention to which of van der Vecht's (1966) subspecies or forms their “ P. indica ” corresponded. Yamane et al. (1995) also mentioned that “Sonan's description of male antenna undoubtedly shows that the males examined by him are also of P. i n d i c a.” This statement might have been made by referring to van der Vecht (1966); but the male characteristics of P. indica given in van der Vecht (1966: 23) are only “Antennae long and slender, the third and fourth segments more than six and four times as long as wide, respectively.” Thus Yamane et al.'s (1995) synonymy was based on poor grounds and Parapolybia takasagona Sonan should be treated as a valid species at least until the concepts of P. in di c a and nominal species-group taxa that are now treated as subspecies of P. in di c a are established.