Potential host colonization by insect herbivores in a warmer climate: a transplant experiment

We conducted a transplant experiment to investigate the potential colonization of a plant species by insect herbivores under a warmer climate. Acacia falcata seeds collected from four latitudes, encompassing the current coastal range of the species (1150 km), were grown in the same soil type and climatic conditions in a glasshouse. Plants were then transplanted to two sites, 280 km north of A. falcata’s current coastal range; the transplant sites were 1.2 and 5.5 1C warmer than the northernmost and southernmost boundaries of the species ’ current range, respectively. We compared the structure and composition of the herbivorous Hemiptera and Coleoptera communities on the transplants (i) to that of A. falcata within its current distribution, (ii) to a closely related Acacia species (Acacia leptostachya) that naturally occurred at the transplant sites, and (iii) among the A. falcata transplants originating from seeds collected at different latitudes. Herbivory on A. falcata was also compared between the transplants and the current distribution, and among transplant originating from different latitudes. Thirty species of externally feeding herbivorous Coleoptera and Hemiptera were collected from the transplante