これまで本州と北海道から知られている。寄主植物はヤナギ類の葉。本種は雌雄異形で、オスの触角第6節はやや長く発達し、メスのそれとは異なり、第1～5節を足した長さの0.4倍程度の長さ。ヨーロッパのヤナギ類に見られるM. salicis (Reuter, 1879)は本種に似るが、メスの腹部第7腹板のS1刺毛が後縁から生じること（本種では後縁より前方から生じる）、オスの触角第6節は第１～５節を足した長さの約0.3倍とやや短いことで識別できる。

This species had been recorded from Honshu and Hokkaido, Japan. It is breeds on the leaves of Salix. this species indicates distinct sexual dimorphism in the antennal length. In male, antennal segment VI is slightly longer than in female, and about 0.4 times as times as long as combined length of segments I–V. An European species M. salicis (Reuter, 1879), which is collected from Salix is very similar to this species but it can be distinguished from this species by female sternite VII with S1 setae arising from the posterior margin (S1 arising from in front of the posterior margin in M. japonicus) and male antennal segment VI slightly shorter (about 0.3 times as long as combined length of segments I–V).

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  Female

  

  Female

  

  Female, head and thorax

  

  Male

  

  Male

  

  Male, head & thorax