Platyptilia carduidactyla seed predation on Cirsium palustre and Cirsium muticum: invasive and management implications.

Abstract

The invasive thistle Cirsium palustre invades the region of the native thistle Cirsium muticum. These two species share a common seed predator, the larvae of Platyptilia carduidactyla. I have conducted three experiments to determine the seed preference, flower head preference and infestation of these two thistles in a common site. The results of these experiments demonstrate the preferred host of the larvae and the level of infestation of each species. The conclusions drawn from these results are suggestive of the degree of Cirsium palustre's invasiveness and management measures that can be applied to the invader's population to keep in check.