Trichagalma serratae ( Ashmead, 1904 ), 1929

IRENE LOBATO-VILA, ALBA SALA-NISHIKAWA, GEORGE MELIKA, GRAHAM N. STONE, CHANGTI TANG, MAN-MIAO YANG, ZHIQIANG FANG, YING ZHU, YIPING WANG, SUNGHOON JUNG, JAMES A. NICHOLLS & JULI PUJADE-VILLAR, 2022, A catalogue, revision, and regional perspective of Eastern Palaearctic and Oriental oak gall wasps and their inquilines (Hymenoptera: Cynipidae: Cynipini, Synergini, Ceroptresini), Zootaxa 5161 (1), pp. 1-71 : 32

Trichagalma serratae ( Ashmead, 1904)

Dryophanta serratae Ashmead, 1904: 80 ; Niijima (1913: 291), ǒ.

Trichagalma drouardi Mayr, 1907: 5 , ǒ [syn. in Monzen (1929: 348)].

Trichagalma serratae (Ashmead) Monzen (1929: 347) ; Melika et al. (2010: 10), ǒ.

Neuroterus serratae (Ashmead) Abe (2006: 289) , ♂ ♀ & ǒ.

Distribution. China (Beijing Province) ( Abe et al. 2007: 200), Japan (Honshu, Kyushu, Shikoku; presumably also Hokkaido, see Remarks 2 below) ( Ashmead 1904: 80; Mukaigawa 1922: 206; Monzen 1929: 348; Monzen 1931: 193; Shinji 1944: 65 (photo 109); Sakagami 1952: 73; Shiraki 1952: 103; Masuda 1972: 222; Yukawa & Masuda 1996: 132, 143; Abe 2006: 292), and Korean Peninsula ( Saito 1932: 101; Shiraki 1952: 103; Kim et al. 1994: 223, Yukawa & Masuda 1996: 132, 143; Abe 2006: 292; Abe et al. 2007: 200; Pujade-Villar et al. 2020a: 1219).

Remarks. Yukawa & Masuda (1996) experimentally closed the lifecycle (linking the sexual (C-100) and asexual (C-073) generations) of T. serratae . Melika et al. (2010), Masuda (1972) and Usuba (1995) (the latter according to Abe (2006)) also mentioned the alternating generations of this species. The sexual generation was described by Abe (2006).

Remarks (2). According to the original description, this species occurs in Hokkaido (northern Japan) on Q. serrata (sect. Quercus ), but it has not been re-collected from this oak species since its description ( Abe 2006) (except by Shinji (1944); see Remarks 3 below). Later, this gall wasp was found on Q. acutissima and Q. variabilis (sect. Cerris ). However, neither Q. acutissima nor Q. variabilis are found in Hokkaido ( Kitamura & Murata 1984; Abe 2006). Therefore, we face two possible scenarios: the host plant originally mentioned in Ashmead (1904) is erroneous or, as suggested by Sakagami (1952), the presence of this gall wasp in Hokkaido is questionable.

Remarks (3). Shinji (1944) mentioned Q. serrata as the host plant. However, this association is probably erroneous (see Remarks 2 above), so we do not include it in Table 1.

Biology. The catkin galls of the sexual generation and the detachable twig galls of the asexual generation both develop on Q. acutissima and Q. variabilis (sect. Cerris ) ( Table 1; Yukawa & Masuda 1996; Abe 2006; Melika et al. 2010).