Perineura okutanii Takeuchi, 1959

Kumar, Deepthi S & Sankar, Manimuthu M, 2023, Taxonomic Notes and New Distribution and Host Plant Records for Sawflies and Woodwasps (Hymenoptera, Symphyta) of Japan VIII, Bulletin of the National Museum of Nature and Science. Series A, Zoology 49 (2), pp. 57-74 : 69

Perineura okutanii Takeuchi, 1959

Japanese name: Ajisai-habachi

( Fig. 10 )

Larva. Late instar ( Fig. 10A–B ): Head pale olive, with large black spot around stemmatum; trunk pale greenish, with sparse minute whitish tubercles dorsally.

Material examined. HONSHU: Tochigi Pref.: 2 $ ( Fig. 10C ), Nakagawa, Oyamada, coll. larvae on Hydrangea macrophylla f. macrophylla , 31. V. 2016, mat. 5. VI., em. 11. IV. 2017, S. Ibuki.

Host plants. Hydrangeaceae : Hydrangea hortensia (= Hydrangea macrophylla (Thunb.) Ser. f. hortensia (Lam.) Rehder ) ( Takeuchi, 1949); Hydrangea macrophylla Seringe (= Hydrangea macrophylla (Thunb.) Ser. f. normalis (E.H.Wilson) H.Hara) ( Okutani, 1967); Hydrangea macrophylla (Thunb.) Ser. f. macrophylla (new record). Takeuchi (1959) noted lLarva feeds on Hydrangea spp. z.

Life history. Ibuki found two late instar larvae solitarily feeding on Hydrangea macrophylla f. macrophylla on May 31, 2016, in Nakagawa, Tochigi Prefecture. The larvae were not coiled at rest. They matured on June 5 and entered the soil. Two female adults emerged on April 11, 2017. This species is regarded as univoltine.

Remarks. As suggested by Takeuchi (1959), this species is thought to be the sawfly long known in Japan as lAjisai-habachiz (=hydrangea sawfly) ( Sasaki, 1923), a pest of hydrangea. Sasaki (1923) gave concise notes on the morphology, life history and damage of this species. His description of the late-instar (lmaturez) larva differs from the larva shown in Fig. 10A–B in the head coloration. According to Sasaki (1923), the head of the larva is black, whereas the head is pale olive in our material. We need more information to confirm if this difference is within a variation range of the species.

Figures

Fig. 10.ɹPerineura okutanii. A–B, Late instar larva on Hydrangea macrophylla f. macrophylla, Oyamada, 31. V. 2016; C, two females, emerged, 11. IV. 2017. Photographed by Ibuki.