Data of Behavior of higher trophic levels associated with an invasive plant varies among populations
Invasive plants from their native and introduced ranges differ in their interactions with herbivores but it is not known whether they also vary in their interactions with herbivore natural enemies. Here, we used olfactometer bioassays and cage experiments to investigate how foraging behaviors of two parasitoid and one hyperparasitoid species depended on plant population origin (i.e., plants from populations in the native range vs. those from populations in the invasive range). Chinese tallow tree (Triadica sebifera) is native to China but invasive in the USA. In China, it is fed on by a specialist noctuid (Gadirtha fusca) which hosts a Braconid parasitoid (Apanteles sp.) and Eurytomid hyperparasitoid plus a generalist aphid (Toxoptera odinae) parasitized by a Braconid (Lysiphlebus confusus). We found that both parasitoid species preferred T. sebifera plants infested by their host over herbivore-free plants in olfactometer bioassays. In addition, both Apantales sp. and Eurytomid wasps preferred G. fusca infested plants from China populations over those from USA populations in olfactometer bioassays but L. confusus wasps did not discriminate between T. odinae infested plants from China vs. USA populations. Similarly, G. fusca caterpillars on China population plants were more likely to be parasitized than ones on USA population plants when they were in the same cage but odds of parasitism for T. odinae did not differ for those on China vs. USA population plants. These results suggest that populations from the native and introduced ranges may differ in traits that impact higher trophic levels. This may have important implications for the success of invasive plants as biocontrol agents are introduced or herbivores begin to feed on them in their introduced ranges. So, these results for be of interest to ecologists and natural resource managers confronting invasive plant species.