Are exotic host plants a life raft or a trap for butterflies?

Many landscapes across the world are dominated by exotic (non-native) plant species. These plants can directly impact native species, including insect herbivores. There are many reported cases of native butterfly species using exotic host plants, and these new interactions have had diverse effects on butterfly populations. In this mini-review, I highlight recent developments in the study of the effects of exotic host plants on butterflies, focusing on two areas that have seen major advances: the genetic basis of host use and the influence of other trophic levels on butterfly-plant interactions. Understanding how these multiple factors interact is a key outstanding question for better predicting if an exotic plant might be a trap or a life raft for a herbivorous insect.

Automated summary

Many landscapes worldwide are dominated by non-native plant species, which can have direct impacts on native species including insect herbivores. Native butterfly species are often reported to use exotic host plants, and these interactions can have diverse effects on butterfly populations. Recent developments in the study of the effects of exotic host plants on butterflies have focused on the genetic basis of host use and the influence of other trophic levels on butterfly-plant interactions. Understanding how these factors interact is crucial for predicting whether an exotic plant will be beneficial or detrimental for herbivorous insects.