The monospecific genus Kaochiaoja (Aphididae: Aphidinae) was elected by Tao (1963) based on the type species Kaochiaoja arthraxonis (Takahashi, 1921) from Taiwan. Subsequently, this species has been recorded in India as Micromyzus granotiae (Ghosh et al., 1970) and Japan as K. pollinae (Miyazaki, 1971). Later, both species were synonymyzed as K. arthraxonis (Eastop and Blackman, 2005; Remaudière and Remaudière, 1997). This species is associated with various host-plants belonging to the family Poaceae such as Arthraxon sp., Digitaria adscendens, Garnotia sp. and Microstegium vimineum.

In this study, the genus Kaochiaoja is newly reported in Korea, based on K. arthraxonis collected on Arthraxon hispidius. A diagnostic note, biometric data and illustrations are given for apterous viviparous females.

Materials and Methods

Aphid samples were collected in Korea in 2014. Samples were preserved in 90% ethanol for a month, and then mounted in Canada balsam, following the method of Blackman and Eastop (2000) and Martin’s (1983) methods. Illustrations for the species were taken by a digital camera attached to the microscope (Leica 400B, Leica Microsystems, Germany) at a resolution of 600 dpi. Measurements for each specimen are taken from the digital images by using image analysis software (Active measure ver. 3.0.3 from Mitani Co. Ltd, Japan). All specimens were preserved in the College of Agriculture and Life sciences, Seoul National University Korea (CALS).

Abbreviations used for diagnosis and biometric data are: ANT I-VI, antennal segments I-VI; BASE, base of the last antennal segment; PT, processus terminalis of the last antennal segment; BD III, basal diameter of antennal segment III; Ls ANT III, longest setae on ANT III; HT II, second segment of hind tarsus; SIPH, siphunculus; URS, ultimate rostral segment.

Taxonomy

Genus KaochiaojaTao, 1963 조개풀수염진딧물속(신칭)

KaochiaojaTao, 1963: 169.

KaochiaojaTao, 1963: Miyazaki, 1971: 134; Eastop and Hille Ris Lambers, 1976: 232; Remaudière and Remaudière, 1997: 105; Nieto Nafría et al., 2011: 232; Joshi and Blackman, 2017.

Type species: Myzus arthraxonis (Takahashi, 1921).

Diagnosis. This genus is morphologically very similar to Neomyzus Goot, 1915 by having blunted setae on head and distinct dark dorsal patches, but can be distinguished by having no secondary sensoria in apterous viviparae (Eastop and Blackman, 2005).

Remarks. Systematic position of this genus has been highly controversial. Hille Ris Lambers considered this genus as Neomyzus van der Goot, 1915 and Basu (1970) followed his suggestion. However, additional studies on comparing these two genera have not yet been conducted.

Kaochiaoja arthroxonis (Takahashi, 1921) 조개풀수염진딧물 (신칭) (Table 1; Figs. 1, 2)

Myzus arthroxoniTakahashi, 1921: 17, 22.

Myzus arthroxoniTakahashi, 1921: Takahashi, 1923: 83.

Kaochiaoja arthraxonaTao, 1963: 169.

Aulacorthum (Neomyzus) anthraxoniBasu, 1970: 357.

Kaochiaoja arthraxonisEastop and Hille Ris Lambers, 1976: 232, 262, 296; Remaudière and Remaudière, 1997: 105.

Macrosiphum pollinaeShinji, 1924: 364.

Micromyzus granotiaeGhosh et al., 1970: 199.

Diagnosis. Apterous viviparous female. Body oval, 1.23- 1.39 mm. Head pigmented with strong spicules dorsally and ventrally, head dorsum with 6 short and blunted setae, antennal tubercle developed. Antenna 1.05-1.14 × body length, ANT I-VI imbricated, antennal setae blunted almost invisible, without secondary sensoria, PT 3.55-5.10 × BASE. Rostrum not reaching or barely reaching middle coxae, URS short with 6 pointed setae. Meso- and metanotum, abdominal tergites I-IV and VI-VIII pigmented with reticulate pattern. SIPH 0.13-0.16mm long, broadly reticulated with distal flange. Cauda cornical shaped 0.13-0.16 mm with 6-7 pointed hairs.

Materials examined. 15 apterous viviparous females, Mt. Chilgapsan, Cheongyang-gun, Chungcheongnam-do, South Korea, Hyoseok Lee leg., on Arthraxon hispidius (Poaceae), 26.vii.2014, no. 140726HS-2.

Host plant. Poacea: Arthraxon hispidius (Korea), Digitaria adscendens (Japan), Garnotia sp. (India) and Microstegium vimineum (Japan).

Distribution. Korea, Japan, Taiwan and India.

Remarks. This species is new to Korea. Currently, this species is only collected in Mt. Chilgapsan in Korea. According to Miyazaki (1971), body color is variable in life (salmon pink to reddish brown with shine). Korean specimens also exhibit variable body color (Fig. 1). The only other congeneric species, K. sikkimensisJoshi and Blackman, 2017, has entirely shining black body (Joshi and Blackman, 2017).