Member States shall without delay notify the Commission, in writing, of the early detection of the introduction or presence of invasive alien species of Union concern and inform the other Member States, in particular of:
(a)
the appearance on their territory or part of their territory of any species included on the Union list whose presence was previously unknown in their territory or in part of their territory;
(b)
the re-appearance on their territory or part of their territory of any species included on the Union list after it has been reported as eradicated.