Abstract
•We conducted native range surveys of insect herbivores of Acacia auriculiformis.•Three closely related allopatric congener Acacia species were also sampled.•DNA barcoding identified 143 MOTUs, with 85% on only a single Acacia species.•Allopatric Australian A. auriculiformis populations shared seven herbivore MOTUs.•Macrobathra spp. and Calomela intemerata are promising potential biocontrol agents.
Acacia auriculiformis is a native Australian tree that has developed into a damaging environmental weed in Florida, USA. We conducted field surveys to collect insect herbivores from A. auriculiformis and three closely related allopatric congeners (A. crassa, A. leiocalyx, and A. concurrens) across the native distribution of each plant species. We collected over 800 specimens, comprising a diversity of herbivorous insect groups, and successfully sequenced 480 specimens for DNA barcoding to group them into molecular operational taxonomic units (MOTUs) as a first step in documenting this diversity. Most herbivores (85%) were found on only a single Acacia species, suggesting each Acacia species hosts its own unique herbivore complex. The Northern Territory and Far North Queensland A. auriculiformis populations are allopatric in relation to one another but hosted a similar suite of herbivores. Calomela intemerata and seven lepidopteran species (including three species of Macrobathra moths) were particularly abundant across both regions. These herbivores look promising as potential biological control agents, though their host-specificity and genetic diversity should be investigated further.