Takecallis taiwana (Takahashi, 1926)

Lee, Yerim & Lee, Seunghwan, 2018, A review of the genus Takecallis Mastumura in Korea with the description of a new species (Hemiptera, Aphididae), ZooKeys 748, pp. 131-149 : 140-144

Takecallis taiwana (Takahashi, 1926) Fig. 5, Table 1

Therioaphis tectae Tissot, 1932.

Material examined.

6 alate viviparous females, Seoguipo-si, JJ, South Korea, 33°15'3"N, 126°32'38"E, on Sasa sp., W.H. Paik leg., 25.iv.1971, no. 6196; 8 alate viviparous females, Seoguipo-si, JJ, South Korea, 33°15'3"N, 126°32'38"E, on Sasa sp., W.H. Paik leg., 15.x.1971, no. 6799.

Description.

Alate viviparous female: Color in life. Not available in this study.

Morphology. Body oval, BL 2.21-2.48 mm long. Head with three pairs of anterior and two pairs of posterior pointed discal setae about 0.04-0.05mm, median protrusion on frons developed, epicranial suture and antennal tubercle developed, head dorsum with a central black stripe, spinal tubercle not developed. ANT 6-segmented 0.73-0.79 × BL, ANT III longest with 5-7 transversely elliptical secondary rhinaria in a row on basal 1/3 of the segment, longest setae on ANT III 0.33-0.67 × BD III, from distal half of ANT III to ANT VI imbricated, ANT IV without secondary rhinaria, PT 0.901.06 × BASE. Clypeus with nose-like processus, rostrum very short, reaching to fore coxae, URS short blunted 0.07 mm long with 4-5 accessory setae, URS × 0.35-0.44 BASE, 0.54-0.64 × HT 2. Thorax smooth, without tubercles. Fore coxae weakly enlarged, longest setae on TIB 0.08-1.00 × middle width of TIB, first tarsal segments with 5-7 setae, HT 2 0.11-0.13 mm long. Wing veins Co and Pts of forewing slightly dark. Dorsal ABD TERG I–VII with a pair of spinal setae on small elevations, ABD TERG VIII with 2 setae. SIPH cylindrical, 0.04-0.06 mm long. Cauda knobbed 0.15-0.20 mm long with 12-13 setae. Anal plate bilobed, each lobe with ten setae.

Distribution.

This species is widely distributed in Southeast Asia; Korea ( Paik 1965), China ( Qiao and Zhang 2004), Japan ( Higuchi 1968), and Taiwan ( Higuchi 1968). It has been introduced into Europe ( Higuchi 1968, Maslyakov and Izhevsky 2011, Ripka 2008, Simala et al. 2008), South Africa ( Quednau 1962), New Zealand ( Blackman and Eastop 2017), North America ( Halbert et al. 2000), and South America ( Foureaux and Kato 1999, Lazzari et al. 1999).

Host plants.

Arundinaria spp., Bambusa spp., Phyllostachys spp., and Sasa spp. ( Poaceae ).

Remarks.

This species was misidentified as T. sasae by Paik (1972) in Korea. Later it was revised to T. taiwana by Quednau and Lee (2001).

Key to species of the genus Takecallis in Korea (Fig. 6)

Molecular analyses and discussion

The NJ tree of partial COI sequences suggested that 63 sequences are distinctly divided into six groups (Fig. 7). This result clearly represented each morpho-specific group except the T. arundicolens complex. The T. arundicolens complex was separated into two genetically distinct groups (Fig. 7). Genetic distances between the two T. arundicolens groups ranged from 7.16 % to 9.36 %. These intraspecific divergence values are much higher than the general species delimitation value of 2.5 % in the subfamily Calaphidinae ( Lee et al. 2017). In the previous study, Lee et al. (2017) suggested that this species complex seems to include at least 2 distinct species. However, it is very difficult to determine which one is the original species because morphological differences between genetically distinct groups were only observed in alatoid nymphs ( Lee et al. 2017). Therefore, to solve this issue explicitly, additional studies are needed.

Except for the T. arundicolens complex, the rest of the four species showed 0 % of intraspecific genetic divergence (Table 2). Interspecific distances among the five species ranged from 5.71 % to 14.44 % (Table 2). T. sasae and T. taiwana showed the lowest interspecific distance level (Table 2). Overall mean genetic distance was 8.91 % for the 63 partial COI sequences of the five Takecallis species.

Molecular evidence strongly indicates the validity of T. alba sp. n. All of the individuals of T. alba sp. n. were grouped together and this group was clearly separated from other species groups with a high interspecific distance level that ranged from 9.36 % to 13.46 % (Table 2). Morphological characteristics of this species correspond to molecular evidence. Although we could not test all Takecallis species from all over the world, this species also has morphological characteristics that distinguish it from all known species. Morphologically, T. alba sp. n. is most similar to T. affinis and T. assumenta . However, its number of accessory setae on URS and the arrangement of secondary rhinaria on ANT III are clearly distinct from the above two species.

In the present study, four Takecallis species were recognized from Korea. Our study demonstrated that the four species are clearly separated based on morphological and molecular evidence. However, the taxonomic status of genetically distinct groups within the T. arundicolens complex still needs to be resolved.