Robackia Saether

Robackia Saether, 1977: 123 .

Saether (1977) erected the genus Robackia recognizing three species, R. demeijerei (Kruseman, 1933), R. claviger (Townes, 1945), and R. pilicauda Saether, 1977, and provided keys to the larvae (except R. pilicauda), pupae, and males. R. demeijerei is recorded from the Russian Far East (Makarchenko et al. 2000); R. pilicauda from North Korea and China (Reiss 1980; Wang et al. 1991).

Within the Harnischia complex, the males of Acalcarella Shilova, Robackia, and Parachironomus Lenz are similar in having a small inferior volsella and a digitiform superior volsella that is more than 2.5 times as long as wide. Robackia has a clavate gonostylus, which is widest near apex (Cranston et al. 1989). The larva of Robackia differs from other Chironomini with the exceptions of Beckidia and Demicryptochironomus Lenz in possessing 7 antennal segments and a slender, seta-like SII (Pinder & Reiss 1983).

There are five previous records of Robackia from Japan: Kitagawa (1997a: 165–166, as Robackia sp. RA, Kiso River, Gifu Prefecture, description); Tojo et al. (1997: 54, as Robackia sp., Surigami River, Fukushima Prefecture, catalog); Kato et al. (2003: 332, as Robackia sp., Kizu River, Kyohtanabe, Kyoto Prefecture, catalog); Inoue et al. (2003: 336, as Robackia sp., Kizu River, Kyohtanabe, Kyoto Prefecture, catalog); Kitagawa (2005: 33, 35, as Robackia sp. RB, Kumano River, Mie / Wakayama Prefectures, catalog). Further, Yamamoto (2001: 253, Fig. 232; 2005: 1140, Fig. 108) mentioned that he had found Robackia sp. larvae and redrew the figure of the male hypopygium of R. claviger from Saether (1977: 127, Fig. 46C), but did not give any information on the distribution of the genus in Japan. Since all records of Robackia from Japan have been based on larvae only, the identity of the species has not been known.

FIGURE Chernovskiia orbicus (Townes, 1945), larva. A, antenna. B, tip of antenna. C, mandible. D, mentum and ventromental plates. E, premandible. F, premento-hypopharyngial complex. G, body segment VIII–IX. H, anal part.