Samia ricini (Jones, 1791)

Wu, Yujie, Peigler, Richard S. & Liu, Zhengyang, 2025, Ecological observations on the genus Samia Hübner, 1819 (Lepidoptera, Saturniidae) of China, especially the natural hostplants, Nota Lepidopterologica 48, pp. 251-268 : 251-268

4. Samia ricini (Jones, 1791)

Fig. 2 A, B

Material examined.

No observation in the wild.

Notes.

The famous eri silkworm / silkmoth, an artificial hybrid with no populations in nature. In China, the main captive hosts are Ricinus communis ( Euphorbiaceae ), Manihot esculenta ( Euphorbiaceae ) and C. nepalensis (e. g., Wei et al. 1998). Adults usually have greyish wings with denser white hairs covering the abdomen. The larval stage has five-instars and, depending on the varieties, the mature caterpillar has a background colour from white (Fig. 3 N ), to pale yellow, to blue, sometimes adorned with black patches. In southern China, the generation length is about two months, normally without diapause but overwintering in pupal form under laboratory condition (e. g., Cheng 1959). Cocoons of S. ricini are white or rufous (“ red eri ”), and always attached on hostplants without peduncle. Japanese sericulturists introduced this species to Taiwan Island from India for trial breeding ( Koidsumi et al. 1941: 3) in 1919, and began to promote such industry in northeastern China (“ Manchuria ”), as well as in Shanghai, Beijing, Nanjing and Wuhan since 1940 ( Matsumura 1943: 38–57, 64–70), but these ventures were all ultimately unsuccessful ( Lu 1947). Between 1945 and 1949, some sericultural farms in Jiangsu introduced this species from Taiwan for breeding ( Wang 1995: 504), and after the founding of the People’s Republic of China, S. ricini was reintroduced to mainland from India by the Chinese Academy of Sciences in 1951 and commercial breeding commenced in 1954 ( Zhu 1959). This species is still farmed principally in southern provinces such as Guangdong and Guangxi.

Figures

Figure 2. Adults of Samia spp. of China, dorsal views. A. S. ricini ♂, Longzhou County, Chongzuo, Guangxi, ca. 130 m, July 2023; B. S. ricini ♀, Longzhou County, Chongzuo, Guangxi, ca. 130 m, July 2023; C. S. canningi ♂, Menglun Town, Mengla County, Xishuangbanna, Yunnan, ca. 650 m, May to November 2022; D. S. canningi ♀, Menglun Town, Mengla County, Xishuangbanna, Yunnan, ca. 650 m, May to November 2022; E. S. watsoni ♂, Nibashan, Yingjing County, Ya’an, Sichuan, ca. 3200 m, 08 June 2023; F. S. watsoni ♀, Nibashan, Yingjing County, Ya’an, Sichuan, ca. 3200 m, 08 June 2023. Scale bar: 3 cm.

Figure 3. Preimaginal materials of Samia spp. of China. A – I, K – M, P. Individuals photographed in the wild. N, O, Q. Captive individuals. A. Ova of S. wangi on leaf underside of Styrax sp., Hangzhou; B. Ovum shells of S. kohlli on leaf underside of Z. armatum, Kunming; C. Ovum shells of S. watsoni on leaf upperside of P. corymbosus, Hangzhou; D. Ovum shells of S. watsoni on leaf upperside of S. gemmata, Hangzhou; E. Larval cluster of S. wangi L 3, dorsal view, on leaf underside of H. acerba, Hangzhou; F. Larval cluster of S. kohlli L 2 (pre-ecdysis), dorsal view, on leaf underside of Z. armatum, Kunming; G. S. watsoni L 2, dorsal view, on leaf underside of P. corymbosus, Hangzhou; H. S. kohlli L 3, dorsal view, on the leaf underside of C. nepalensis, Kunming; I. S. watsoni L 4, dorsolateral view, on leaf underside of P. corymbosus, Hangzhou; J. S. cynthia L 5 (mature), dorsolateral view, on C. officinarum; K. S. wangi L 5 (mature), lateral view, on S. japonica, Hangzhou; L. S. kohlli L 5 (mature), lateral view, on C. nepalensis, Kunming; M. S. canningi L 5 (mature), lateral view, on Zanthoxylum sp., Xishuangbanna; N. S. ricini L 5 (mature), lateral view, on C. nepalensis; O. S. watsoni L 5 (mature), lateral view, on P. corymbosus; P. Cocoon of S. wangi, on C. officinarum, Shanghai; Q. Cocoon of S. watsoni, on P. corymbosus.