## 1 Introduction  
Aphids (Hemiptera, Aphididae), due to the seasonal polymorphism and complex life cycles, are insects difficult to identify. Thus, the usability of DNA barcoding, a fragment of the mitochondrial cytochrome oxidase subunit I (COI) gene, has been used for additional diagnostic data in species identification [1; 2; 3; 4]. Moreover, DNA barcoding enables the detection of cryptic species and the reassessment of species diversity delimitation on various taxonomic levels [6; 7; 8; 9].  
The bamboo feeding aphid genus _Takecallis_ [PERSON] contains seven taxa of oriental origin: _T. affinis affinis_ [PERSON], _T. affinis initiative_ Augandensis [PERSON], _T. alba_ [PERSON], _T. arundicolens_ ([PERSON]), _T. arundinariae_ ([PERSON]), _T. assumenta_ [PERSON] and [PERSON], _T. sasae_ ([PERSON]), and _T. tativana_ ([PERSON]) [10]. [PERSON] (1917) [11] erected _Takecallis_ for _Callipterus arundicolens_ [PERSON] (_= T. bambusae_ [PERSON], 1917). The genus was revised by [PERSON] (1969) [12] and later reviewed by [PERSON] (2003) [13]. The author synonymized _T. takahashi_ [PERSON] with _T. arundinariae_, described _T. affinis initiative_ [PERSON]_, and provided keys to species and illustrations of all available morphs. [PERSON] and [PERSON] (2004) [14] reviewed the genus _Takecallis_ from China and described _T. assumenta_. Recently, _T. alba_ from Korea was distinguished based on morphological and molecular evidence [15]. Moreover, comprehensive assessment of DNA barcodes for the subfamily Calaphidinae revealed deep intraspecific divergence within the species complex of _T. arundicolens_, which indicates that there is more than one species under this name [6]. In their natural range, all known species of this genus are restricted to East Asia (China, India, Japan, Korea, Manchurian subregion, Taiwan). Three species--_T. arundicolens, T. arundinariae_ and _T. tativana_ are now widely distributed and introduced to other continents, including Europe [16]. All of them are treated as a pest on Bambusoideae, i.e., _Arundinaria_ spp., _Bambus_ spp., _Phylostachys_ spp., and _Sasa_ spp. [13; 17].  
Aphids, as herbivorous sap-sucking insects, can cause considerable damage to crops and ornamental plants, and also as virus vectors. Therefore, it is very important to use sustainable strategies for their management. In order to use them, it is important to identify the pest correctly, and choose the right methods of its control. An examination of aphid samples collected in 2022 from the cold hardy bamboo variety _Fargesia rufa_ T.P. [PERSON] revealed the first detection of the genus _Takecallis_ from Poland. These specimens were firstly classified as belonging to the _T. arundicolens_ complex [18]. In order to exclude whether the material collected in Poland is a color variant of _T. arundicolens_ or an unknown cryptic species of this genus, detailed morphometric studies together with analyses of a mitochondrial COI (DNA barcoding) and nuclear elongation factor 1 (EF1\(\alpha\)) gene sequences were undertaken, and the results are presented in this paper. In addition, the material collected from Poland was compared with aphids feeding on various species of bamboo, collected in 2023 in the Meise Botanic Garden, Belgium.