If what they say in the article is true:
"As it happens, Arundo won’t lay eggs in anything but carrizo."
Then there will be limits on what the Arundo wasp can do to damage the environment. They can only be in areas with the invasive carrizo cane. If they were able to completely destroy the carrizo (which is doubtful), then they would die out, assuming that the article has it right about the laying of the eggs.
Of course, that still does not tell us what affect they would have on things in the areas where the carrizo cane is.
"As it happens, Arundo won’t lay eggs in anything but carrizo."
Then there will be limits on what the Arundo wasp can do to damage the environment. They can only be in areas with the invasive carrizo cane. If they were able to completely destroy the carrizo (which is doubtful), then they would die out, assuming that the article has it right about the laying of the eggs.
Of course, that still does not tell us what affect they would have on things in the areas where the carrizo cane is.
"A wise man ... proportions his belief to the evidence."
— David Hume, An Enquiry Concerning Human Understanding, Section X, Part I.