Two moths have passed a major test towards becoming approved biocontrol agents for swallow-wort vines (Vincetoxicum spp.). Swallow-wort is related to milkweeds, but these moth larvae appear to specialize on swallow-wort and don’t touch native milkweeds.
http://www.northeastipm.org/about-us/publications/ipm-insights/swallow-wort-biocontrols-pass-test/