Siobla ferox (Smith, 1874)

Fu, Yuanzun, Yuan, Yuan, Shen, Qian, Xu, Hao, Ye, Zheng, Guo, Li, Wu, Xiaoliang & Zhao, Yunhe, 2021, Taxonomic Notes and New Distribution and Host Plant Records for Sawflies and Woodwasps (Hymenoptera, Symphyta) of Japan VI, Bulletin of the National Museum of Nature and Science. Series A, Zoology 47 (4), pp. 163-188 : 182

Siobla ferox (Smith, 1874)

Japanese name: O-koshiaka-habachi

( Fig. 9A–G )

Material examined. HONSHU: Tochigi Pref.: 1 ˁ, Nakagawa, Oyamada, coll. larva, on Actinidea polygama , 14. VI. 2016, mat. 18. VII., em. 2. V. 2017, S. Ibuki; 1 ˁ, Nakagawa, Bicchuzawa, coll. larva ( Fig. 9A ), on Actinidea polygama , 22. VI. 2016, diet changed to Glechoma hederacea subsp. grandis 27. VI., mat. 9. VIII. ( Fig. 9D ), em. 6. V. 2017, S. Ibuki; 1 ˂, Nasukarasuyama, coll. larva, on Actinidea polygama , 15. VI. 2016, mat.?, em. 6. V. 2017, S. Ibuki.

Larva. Middle or late instar ( Fig. 9A–C, E–F ): head dark purplish gray to pale yellowish gray; trunk and legs creamy white, dorsal region pale gray or pale yellowish gray, sparsely covered with minute black spots, each segment with paired yellowish dorsolateral thorns. Mature larva ( Fig. 9D, G ): blackish, shiny; thoracic legs dark yellowish.

Host plants. Actinidiaceae : Actinidia polygama (Siebold et Zucc.) Planch. ex Maxim. (new record). Asteraceae : Cirsium pendulum Fisch. ex DC. ( Okutani, 1967b). Balsaminaceae : Impatiens spp. ( Okutani, 1967b). Lamiaceae : Glechoma hederacea L. subsp. grandis (A. Gray) H. Hara. (new record). Polygonaceae : Polygonum cuspidatum Siebold et Zucc. ( Okutani, 1967b), Rumex sp. ( Okutani, 1967b).

Life history. This is a univoltine species. The larva is a solitary external feeder on various plants. The larval period is very long, about 40 days ( Okutani, 1959) or more than 48 days (see below). On maturity, the reared larva had an extra molt and went into the soil.

Remarks. This is the first record of Actinidia polygama ( Actinidiaceae ) and Glechoma hederacea subsp. grandis ( Lamiaceae ) as the hosts of S. ferox . The known hosts of this species now include more than six species of five families of plants. For a detailed description of the larva, see Okutani (1959). Okutani (1959) noted that the larval period of this species was about 40 days. However, one of our cases of rearing indicated that the period may be much longer. The larva collected on June 22, 2016 ( Fig. 9A , probably middle instar) and reared indoors matured on August 9 (Fig. D). The rearing period from middle instar to maturity in this case lasted 48 days. The full larval period of this individual is esti- mated at 60 days at least.

Figures

Fig. 9. A–G, Siobla ferox: A, probably middle instar larva on Glechoma hederacea subsp. grandis, 27. VI. 2016; B, same larva, probably late instar, 12. VII. 2016; C, same larva, 16. VII. 2016; D, same larva, matured, 9. VIII. 2016; E. probably middle instar larva on Actinidia polygama, 14. VI. 2016; F. probably middle instar lar- vae on A. polygama, 19. VI. 2016; G. same larva, 15. VII. 2016. H–I, Siobla japonica: H, last instar larva, 5. VI. 2019; I, mature larva and cast skin above, 9. VI. 2019; J–M, Taxonus shinoharai: J, middle and late instar larvae on Agrimonia pilosa var. japonica, 29. IX. 2019; K, late instar, 29. IX. 2019; L, same larva, matured, 30. IX. 2019; M, male adult, just emerged, 26. X. 2019. All photographed by Ibuki.