Tetraneura (Tetraneurella) sorini Hille Ris Lambers, 1970

Fundatrix first instar nymph: Body elliptical, becoming thinner posteriorly, 0.76−1.19 (on average 0.93) mm long, 0.31−0.53 (0.42) mm wide on abdominal segment II, 0.38−0.45 (0.41) times as wide as long (Figure 4C). Antennae short, 5-segmented, smooth and not imbricated, 0.18−0.20 (0.18) mm long, 0.54−0.59 (0.57) times the length of hind femorotorochanter (Figure 4F). Fore femorotrochanter 0.15−0.25 (0.20) mm long, fore tibia 0.11−0.20 (0.15) mm long, hind femorotrochanter 0.22−0.43 (0.33) mm long, hind tibia 0.19−0.38 (0.30) mm long (Figure 5F). Rostrum reaching hind coxae; ultimate rostral segment rather slender, 0.10−0.17 (0.14) mm long, 0.28−0.55 (0.41) times as long as the length of hind femorotrochanter.

Emigrant adult: Body elongated oval, 1.95−2.13 (2.08) mm long, without wax gland plates (Figure 6C). Antennae 6-segmented, 0.63−0.70 (0.66) mm long, 0.30−0.35 (0.32) times as long as body, 0.97−1.07 (1.02) times as long as hind tibia (Figure 6F, I). Antennal segment III 0.19−0.23 (0.21) mm long, 1.15−1.28 (1.19) times as long as segment V. Antennal segment IV 0.076 −0.091 (0.085) mm long, segment V 0.17−0.18 (0.17) mm long. Secondary rhinaria present on segments III−V, covering usually 1/3−2/3 circumference of the segments from the ventral side. Ultimate rostral segment 0.095 −0.110 (0.103) mm long, 0.52−0.70 (0.62) times as long as the second segment of hind tarsus (Fig 6L). Hind femorotrochanter 0.45−0.53 (0.494) mm long. Second segment of hind tarsus 0.15−0.18 (0.17) mm long (Figure 6O). First tarsal chaetotaxy 3:2:2. Cornicles absent.

Sexupara adult: Body 1.72−2.94 (2.26) mm long (Figure 7C). Wax gland plates present on the whole body except the posterior segments of abdomen. Antennae 6-segmented, 0.74−0.90 (0.84) mm long, 0.29−0.44 (0.38) times as long as body, 0.96−0.89 (0.94) times as long as the length of hind tibia (Figure 7F, I). Antennal segment III 0.24−0.32 (0.30) mm long, 1.1−1.2 (1.2) times as long as segment V. Antennal segment IV 0.070 −0.095 (0.079) mm long, segment V 0.23−0.27 (0.25) mm long. Secondary rhinaria present on segments III−V, covering usually 1/2−3/4 circumference of the segments from the ventral side. Ultimate rostral segment 0.12−0.17 (0.15) mm long, 0.73−0.84 (0.80) times as long as the second segment of hind tarsus (Figure 8C). Hind femorotrochanter 0.57−0.70 (0.64) mm long, hind tibia 0.78−1.01 (0.89) mm long. Second segment of hind tarsus 0.17−0.20 (0.18) mm long (Figure 8F). First tarsal chaetotaxy 3:2:2. Wax gland plates on marginal abdomen with two types of facets, larger ones of which are present in the center of plate, and small ones present peripherally (Figure 8I, L). Cornicles 0.057 −0.080 (0.070) mm in diameter (Figure 8O).

Host plant: Primary host: U. davidiana var. japonica . Secondary host: Miscanthus sinensis .

Specimens examined: Fundatrix first instar nymph: 5 exs, Ukiha, Fukuoka, 8.IV.1985, on U. parvifolia, S. Akimoto; 10 exs, Bibai, Hokkaido, 5.VI.1981, on U. davidiana var. japonica, S. Akimoto; 14 exs, Aokizawa, Minakami, Gunma, 3.VI.1983, on U. sp., Y. Matsumoto. Emigrant adult: 4 exs, Iwamizawa, Hokkaido, Japan, 15.VI.2009, on U. davidiana var. japonica, S. Akimoto; 8 exs, Hokkaido Univ., Sapporo, Japan, 7.VI.1991, on U. davidiana var. japonica, S. Akimoto; 4 exs, Iitate, Fukushima, 4.VI.2014, on U. davidiana var. japonica, S. Akimoto. Sexupara adult: 12 exs, Yoichi, Hokkaido, 7.X.2017, on U. davidiana var. japonica, S. Akimoto. Other samples from Appendix S1, the supplementary materials in Muramatsu & Akimoto (2016).

Distribution: Japan (Hokkaido, Honshu, and Kyushu), South Korea (Hille Ris Lambers 1970).