Yamatentomon yamato (Imadaté & Yosii, 1956)

Fig. 6.

Acerentulus yamato Imadaté & Yosii, 1956: 11–14, figs. 1–8.

Acerentomon yamato Imadaté & Yosii 1959: 35–37, pl. VIII, figs. 58–63.

Acerella yamato Tuxen 1963: 95; Tuxen 1964: 240–242, figs. 358–359.

Yamatentomon yamato Imadaté 1964: 277, fig. 130; Imadaté 1973, fig. 4; Imadaté 1974a: 614–616; Imadaté 1974b: 107–114, figs. 41–45; Rusek 1974: 270; Imadaté & Szeptycki 1976: 268–269; Yin 1980: 143–145, 154, figs. 42–51; Imadaté 1981: 31, 33, fig. 1; Imadaté 1986: 26–28, figs. 1–3; Imadaté 1994: 50–51; Yin 1999: 274–277, 485, figs. 161, 163; Szeptycki 2007: 97–98; Bu & Wu 2012: 844–846, figs. 21–31; Shrubovych 2014: 148, figs. 44–47; Shrubovych 2020: 9.

= Yamatentomon takapchupi Imadaté, 1964: 281–283, figs. 133–137; Imadaté 1974a: 616; Rusek 1974: 270.

Materials examined. Holotype male (NSMT-Ap 32, mounted on one slide with another male and three females), Nara Park, Nara-shi, Nara Prefecture, Honshu, Japan, elev. 140 m, 21-II-1955, G. Imadaté leg.

Other material examined: Two males, Hikarigaoka, 34°44'36"N, 135°42'56"E, elev. 130 m, deciduous broad-leaved forest dominated by Q. serrata; one female, Houji, evergren broad-leaved forest dominated by Q. glauca, 34°46'57"N, 135°42'36"E, elev. 290 m, 6- IV- 2014, Takayama-chô, Ikoma-shi, Nara Prefecture, Honshu, Japan, Y. Takai leg.; one female, Isaki-ji Fudoson, Shirao-chô, 35°12'13"N, 136°05'26"E, elev. 550 m; one female, Isaki, Okishima-chô, 35°11'48"N, 136°05'30"E, elev. 140 m, Omihachiman-shi, Shiga Prefecture, Honshu, Japan, 12-V-2019, K. Ishii leg.; three males, two females, Nozumi, Teradomari, Nagaoka-shi, Niigata Prefecture, Honshu, Japan, 37°42'08"N, 138°48'04"E, elev. 392 m, deciduous broad-leaved forest dominated by Q. serrata, 14-X-2022, K. Ishii leg.; 18 males, 24 females, eight preimagoes, 19 maturi juniores, six larvae II, three larvae I, Busseki, Nakatsugawa, Chichibu-shi, Saitama Prefecture, Honshu, Japan,, deciduous broad-leaved forest dominated by Fagus crenata and Acer sp., 35°59'47"N, 138°49'31"E, elev. 660 m, 8-V-2001, O. Nakamura leg.; one male, four females, Yumiharidaitôge, Nishikawa-machi, Yamagata Prefecture, Honshu, Japan, 38°27'40"N, 139°59'58"E, elev. 540 m, 29- VII- 2013, K. Ishii leg.; one male, one female (Imadaté’s Proturan Collection in NSMT), the slope of Susong-chon valley, west of Chongzin, Hamgyong-pukto, North Korea, young pine forest under growths of oaks and hazel, litter under hazel, 22-VI-1974, A. Szeptycki leg.

Diagnosis. Cephalic additional setae d6 present, but occasionally absent; tergite VII with six pairs of anterior setae, A4' present; posterior accessory setae on thorax and abdomen all setiform, length more than one-third of P1; accessory setae P3a present on tergites II–VII.

Supplementary notes on description. Bu & Wu (2012) provided a detailed redescription based on specimens from Japan and China. Additionally, Shrubovych (2014) contributed information regarding foretarsal setae β1 and δ4, male squama genitalis and porotaxy on sternites VI and VII. Further notes not included in those redescriptions are presented here.

Cephalic additional setae d6 present or absent (Figs. 6A, B). Foretarsal setae β1 and δ4 long, setiform; β1 length 24 μm, 1.5 times longer than δ1, and about half the length of β2, 51 μm; δ4 length 37 μm, about twice the length of δ1; δ1–δ3 and δ5 short, setiform; δ1 16 μm, δ2 18 μm, and δ3 and δ5 20 μm long (Fig. 6C). Metanotum with pores sl and al (Fig. 6 D).

Notes. Bu & Wu (2012) noted that Japanese specimens possessed the additional cephalic setae d6, while Chinese specimens did not. In the current study, the holotype was examined and found to lack the setae d6. Furthermore, a male and three females on the same slide were examined, and none of them exhibited the setae. In contrast, all other Japanese specimens examined in this study possessed d6. The description of larva I reported by Imadaté included setae d 6 in the chaetotaxy (Imadaté 1986, fig. 1). Szeptycki & Imadaté (1987) also presented a figure of a Japanese species of Yamatentomon sp. that included the setae d6, in comparison to Y. brevisetum. Since Y. yamato is currently the only species exhibiting d 6 in this survey, this Japanese species is considered indicative of Y. yamato. Dr. Shrubovych kindly informed me that specimens of Y. yamato (five males and two females) from the Russian Far East lack the setae d6, while 13 specimens (nine males, two females, one maturus junior, and one larva II) from Yakutia in northeastern Siberia did possess the setae d6. The specimens from North Korea (one male and one female in Imadaté’s Proturan Collection) lack the setae d6. Although both variants are present in this species, approximately 95% of the Japanese specimens examined in this study exhibited the variant with the setae d6, indicating that this variant is generally more common in Japan.

Variation in the position of the pore sam on sternite VII has been observed. In one variant the pore is located on the first connecting line (Bu & Wu 2012, fig. 29), while in the variant it is found at the intersection of connecting lines (Shrubovych 2014, fig. 47). In the holotype, the pores were on the intersection of the connecting lines; however, both types were noted in the specimens examined in this study.

Distribution. Japan, Korea, northeastern China, Russian Far East, northern Siberia.