[n = 6]
| Year / Period | From | To | Established | Ecol. effects |
|---|---|---|---|---|
| unknown | Unknown | Belgium | established | |
| 1960 - 1969 | Unknown | Lithuania | not established | some |
| 1959 | Unknown | Ukraine | unknown | |
| 1960 | Unknown | Latvia | unknown | unknown |
| 1964 | Russia | Estonia | not established | none |
| 1987 | USSR | China | unknown |