[2][3][4][5] The genus is native to East Asia, but they are invasive in many areas of the United States.

[3][5][6] They are a matter of concern in many states, as they disrupt the native forest ecology by affecting soil structure and chemistry.

[3][7] Amynthas species can be differentiated from other earthworms by their clitellum, which is pale, annular, is close to the head, and lies flat against the body.

[8][9] Amynthas species' faster reproduction rate and their ability to reproduce asexually (parthenogenesis) has contributed to their spread into the United States.

[10] Eggs are wrapped in small cocoons, which overwinter while the adults die off at the first freeze each year.