Diagnosis (species group “a”). The species studied here within the species group possesses the widest tegmina, comparatively long files ( Fig. 5 a–f) and widest mirrors ( Fig. 6 a–e). The file is widest in middle, from which teeth are gradually narrowed toward both ends ( Fig. 5 a–f).
Bioacoustics. One song unit is composed of several continuous syllables ( Fig. 1). This species group possesses 5 song types ( Fig. 1, Table 2). The song types of M. himalaya sp. nov. and M. marmorata He are distinguished from other three types by the repeated syllables without amplitude change ( Fig. 1 p–q, s–t). In the other three types, one song unit could be separated into three phases, i.e., low-amplitude beginning and ending phases, and high-amplitude middle climax ( Fig. 1 a–d, f–i, k–n).
Included taxa. M. niponensis ( East Asia), M. fallax He, 2019 ( China), M. crescendo sp. n. ( China), M. himalaya sp. n. ( China), and M. tibetensis sp. n. ( China), and M. marmorata He, 2019 ( China).