The genus Periphyllus van der Hoeven, 1863 (Aphididae: Chaitophoriane) consists of 50 monoecious and holocyclic species (Blackman and Eastop, 2021;Favret, 2021). Most of species in this genus are living on Aceraceae, and some others with Sapindaceae and Hippocastanaceae as host plants (Higuchi, 1972). In Korea, a total of seven species have been recorded: Periphyllus californiensis (Shinji, 1917) was the first recorded by Takahashi (1933);P. koelreuteriae (Takahashi, 1919) and P. viridis (Matsumura, 1919) were recorded by Paik (1972);P. ginnalae (Paik ex Szelegiewicz, 1974) was recorded by Szelegiewicz (1974);P. allogenes (Szelegiewicz, 1981) was recorded by Szelegiewicz (1981);P. kuwanaii (Takahashi, 1919) was recorded by Lee and Seo (1992);P. unmoonsanensis (Park and Park, 1996) was recorded by Park and Park (1996). In 2021, we newly collected samples of Periphyllus acerihabitansZhang, 1982 on Acer buergerianum in Korea.

P. acerihabitans is common species in A. buergerianum, which was firstly described in China (Zhang and Zhong, 1982), providing a simple diagnosis of apterous and alate viviparous individuals. Since then, several morphs including the aestivating nymph and oviparous female of P. acerihabitans were reported in Japan (Wieczorek et al., 2016). In this study, we report apterous viviparous of P. acerihabitans for the first time in Korea.

Materials and Methods

Samples were preserved in 95% ethanol and then mounted Canada balsam, following the method of Blackman and Eastop (2000) methods. Images and measurements were taken by LEICA (DM3000 LED) and LEICA (CTR6 LED). All specimens were deposited Institute of Agriculture & Life Science, Gyeongsang National University. The following abbreviations are used in morphological features: BL - body length from the head to the end of cauda; BW - body width across the abdomen; HW - head width across compound eyes; ANT. I-VI - antennal segments respectively; LS ANT.III - longest seta on ANT.III; LS HEAD - length of longest hair of the head; BD.III - basal articular diameter of ANT.III; BASE - base of ANT.VI; PT - processus terminalis of ANT.VI; URS - Ultimate rostrum segment; FEMORA - hind femora; TIBIAE - hind tibiae; HT.I - first segment of hind tarsus; HT.II - second segment of hind tarsus; ABD.I-VI - stout and long setae of abdominal tergites I-VI; ABD.VII-VIII - stout and long setae of abdominal tergites VII-VIII. Abbreviations were used for the region: JB, Jeollabuk- do; GN, Gyeongsangnam-do.

Systematic Accounts

Periphyllus acerihabitansZhang, 1982 중국단풍진사진딧 물(신칭) (Table 1; Figs. 1-2)

Description of apterous viviparous female. Color. In life: deep green; in mounted specimens: whole body pale, dark brown with tarsus, apices of ANT.III-V, basal, PT.

Morphological characters. Body oval and BL 1.540-2.680 mm (Fig. 1A). Head flat with numerous dorsal hairs (Fig. 1B). ANT 6 segmented, ANT 1.242 - 1.543 mm, 0.575 - 0.806 × BL, and 2.857-3.112 × HW. ANT.I 0.084 - 0.116 mm, with 3 - 9 hairs. ANT.II 0.057 - 0.073, with 4 - 7 hairs. ANT.III 0.380 - 0.470 with 4 - 14 hairs. ANT.IV 0.210 - 0.270 with 2 - 4 hairs. ANT.V 0.199 - 0.250 mm with 2-3 hairs. BASE 0.112 - 0.138 mm with 2 hairs. PT 0.200 - 0.226 mm without hairs. ANT setae fine pointed. LS ANT.III 4.001-7.447 × BD.III (Fig. 1C). FEMORA 0.387 - 0.750 mm. TIBIAE 0.651 - 1.140 mm, rows of short spinules on whole TIBIAE (Fig. 1D). HT 2 segmented, HT.I 0.041 - 0.054 mm, HT.II 0.131 - 0.170 mm, first tarsal chaetotaxy 5:5:5. Rostrum reaching to middle coxae, URS 0.097 - 0.124 mm with 1 - 2 accessory setae, 0.255 - 0.263 × ANT.III and 0.729 - 0.746 × HT.II (Fig. 1E). Abdominal tergites numerous, pointed setae, sometimes present with slightly forked apices on setae. Stout and long setae in spino-pleural areas on abdominal tergites I-VI 0.149 - 0.221 mm long. Abdominal tergites VII-VIII 0.202 - 0.310 mm long, slightly longer than abdominal tergites I-VI. SIPH length 0.089 - 0.170 mm, SIPH width 0.116 - 0.188 mm, with 2 - 3 rows of reticulations formed flange (Fig. 1F). Cauda width 0.107 - 0.206 mm, broadly rounded with 10 - 22 setae (Fig. 1G).

Specimens examined. 3 apterous viviparous from Acer buergerianum Coll.#210429JH88, GNU, Jeonju-si, JB, 29.IV.2021; 6 apterous viviparous from Acer buergerianum Coll.# 210414 JH34, GNU, Jinju-si, GN, 14.IV.2021.

Host plant.Acer buergerianum Miq, 1865

Distributions. Korea (new record), China, Japan

Remark.P. acerihabitans is similar to P. unmoonsanensis in the morphological features. However, P. acerihabitans is noticeable from the host plant, smaller whole body, antenna, and numerous dorsal hairs on the head.

Key to species of the genus Periphyllus in Korea