Tenthredo adusta adusta Motschulsky, 1866

Tenthredo adusta adusta Motschulsky, 1866

( Fig. 2A–H View Fig )

Materials examined. ɹ JAPAN: HONSHU— Kanagawa Pref.: 2 females, Yugawara-machi, Yoshihama, Mt. Makuyama , ca 600 m alt., 29. V . 2021, Y. Kato; 1 female, same data as above, except for oviposited on Angelica pubescens in field and captivity, YK20210529A; 3 final feeding instar larvae (in ethanol), offspring of YK20210529A, hatched 4–6. VI , fixed 19. VI; 1 final instar larva (in ethanol), same data as above, except for fixed 20. VI .

Larva. ɹ Early instar ( Fig. 2B, C View Fig ): Length 6–7 mm; head brownish orange, with ocularium and stemmatum black; trunk translucent opaque white. Middle instar ( Fig. 2D, G View Fig ): Length 10–23 mm; head orange, with ocularium and stemmatum black; antenna dark brown; mandible pale orange, becoming black apically; trunk white to light gray. Final feeding instar ( Fig. 2E, H View Fig ): Length 26–32 mm; color similar to middle instar, but trunk gray to dark gray dorsally, light gray ventrally, with pale brown arrowhead-like dorsal stripe on each segment. Final instar (= mature larva) ( Fig. 2F View Fig ): Length about 26 mm; head orange with dark brownish fleck on anterodorsally; trunk clear orange with dark brown arrowhead-like dorsal stripe on each segments. Trunk covered with thin layer of white wax in all feeding instars.

Host plant. ɹ Apiaceae : Angelica pubescens Maxim. (new record).

Observations and rearing records. ɹ On May 29, 2021, I observed a female ovipositing on a leaf of Angelica pubescens in Yoshihama , Yugawaramachi , Kanagawa Prefecture, Honshu, Japan. After observing oviposition, I collected this female and kept it alive in a container with the same live plant species, and it laid 24 eggs on three leaves under the rearing conditions from May 29 to 30. The eggs were individually inserted in the tissue of the leaf from the upper surface ( Fig. 2A View Fig ). All the eggs hatched between June 4 and 6, and the hatched larvae came out from the undersurface of the leaf ( Fig. 2B View Fig ). The early to middle instar larvae fed on the leaf areas close to the edge and bored holes from the upper surface ( Fig. 2G View Fig ). The late instar larvae fed on the leaves from the edges ( Fig. 2H View Fig ). The larvae were always solitary. All larvae reached the final feeding instar from June 13 to 16 and three of them were fixed in ethanol on June 19. The remaining larvae executed extra molts and matured from June 20 to 22. One of them was fixed in ethanol on June 20 and the others went into the soil but died .

Life history. ɹ According to the collection data listed above and the literature ( Naito et al., 2004), adults were collected only from late May to June in the mountainous areas of Honshu, Japan. Therefore, this species is probably univoltine as in other Tenthredo species (e.g., Shinohara and Ibuki, 2019; Shinohara et al., 2019).

Remarks. ɹ This is the third record of Angelica as a host plant of Japanese Tenthredo . Other two species of Tenthredo associated with Angelica in Japan are Tenthredo fagi Panzer, 1798 and T. providens Smith, 1874 ( Okutani, 1967). The larvae of T. fagi and T. providens may be distinguished from that of T. adusta adusta by the presence of dark colored area on the vertex in the feeding instars ( Lorenz and Kraus, 1957; Okutani, 1959).