Weedati or Weederati:
A blend of “weed” (as in invasive plants) and “-ati” (a suffix often used to refer to a group of people with specific expertise or interest, like in “literati” or “gliterati”).
Invasivisti:
Combining “invasive” with the “-isti” suffix, often used to refer to aficionados or experts, much like “artisti” or “futuristi.”