Denver, Colo. - Western U.S. governors have compiled their first region-wide list of the worst invasive species for their states.
The Western Governors' Association Thursday released a compilation of 50 pests ranging from weeds and wild boars to insects and amphibians.
The governors want to prioritize efforts to defend against the intruders.
Pests that have been in the headlines before include water-gulping salt cedar trees and quagga mussels, which clog water and sewer pipelines.
Others may be surprises, including feral cats.
At least two diseases made the list: white nose syndrome, which infects bats, and whirling disease, which attacks fish.
The association says salt cedars are the worst land-based invasive species. The Eurasian watermilfoil is the worst in the water.
The list is based on a survey of state invasive species coordinators.