Onycholyda sichuanica Shinohara, Naito and Huang 1988

Onycholyda sichuanica Shinohara, Naito and Huang, 1988 (Fig. 3)

Onycholyda sichuanica Shinohara, Naito and Huang, 1988: 92; Xin and Wu, 2010: 10; Shinohara and Wei, 2012: 56.

Onycholyda fanjingshanica Jiang, Wei and Zhu, 2004: 44; Shinohara and Wei, 2012: 56. N. syn.

Distribution. China (Sichuan, Gansu, Guizhou, Guangxi, Hubei, Hunan, Anhui, Fujian).

Host plants. Rubus spp.

Field observations and rearing records. On June 8, 2013, Shinohara found seven leaf-rolls (four of them in Fig. 3 A–D), containing ten larvae, on Rubus spp. at Huatai, ca. 900 m, Mt. Hupingshan, Hunan Province. Of the seven leaf-rolls, one contained three larvae (three egg shells), one contained two larvae (one of them sample no. 486, two egg shells, Fig. 3D, E), while the other five contained one larva, respectively (sample nos. 480–482, 488, 489; for four of them, no egg shells were found, whereas five egg shells were found on the remaining one leaf, Fig. 3B, F). Of the ten larvae, one larva (sample no. 489) matured and was fixed in ethanol on June 9, two (sample nos. 481, 482) on June 10, two (sample nos. 480, 488) on June 11, one (sample no. 486) on June 12, while the remaining four were fixed in ethanol on June 14 before maturation. Six of the ten larvae were used for molecular analysis (Table 1).

All the leaf-rolls and remains of the egg shells were found on the under surface of the leaves and all the egg shells were located on the lateral veins near the base of the leaf (Fig. 3 B–F). The larval abodes were irregular in shape (Fig. 3 A–D).

Larva. Late instar (Fig. 3G, H): Head black; antenna creamy white, each antennomere more or less dark brownish; trunk pale greenish white, terminal segment largely creamy white; thoracic legs and subanal appendage white. Mature larva (Fig. 3I): Similar to the preceding, but antenna pale brown and trunk, including thoracic legs and subanal appendage, vivid pale green.

Remarks. Shinohara and Wei (2012) suspected that O. sichuanica (only males known) and O. fanjingshanica (only females known) are opposite sexes of the same species, because the two “species” had much in common in morphology and were obtained together in the same area on Mt. Yunshan, Hunan Province. Our analysis based on mitochondrial COI+tRNA(Leu)+COII gene sequences perfectly supported the hypothesis that the two taxa are conspecific, and we hereby propose to treat them as synonyms.

The adult specimens from Mt. Yunshan (sample nos. 763, 764, 779, 780) and larval material from Mt. Hupingshan (sample nos. 480–482, 486, 488, 489), both localities in Hunan Province, agreed in mitochondrial COI+tRNA(Leu)+COII gene sequences and we determine the larvae as O. sichuanica. This is the first record of the larvae and host plant of this sawfly.

The previously unknown larva of this species is well characterized by the entirely black head and entirely pale green trunk in late-instar and prepupal stages (Fig. 3 G–I). It is quite similar to that of O. flavicostalis except for the entirely pale cervical sclerite (compare Fig. 3 G–I with Fig. 2D). The larva of the Japanese O. esakii also has a similar color pattern, but the cervical sclerite is black (Shinohara and Kojima 2009). The observed larvae of O. sichuanica were solitary or living together in a small group.