Host-plants of leaf-miners in Australian subtropical rainforest

Leaf-miners are endophytic insect herbivores that are considered to be relatively host-specific compared with other types of insect herbivores, often depending on one or a few congeneric hosts. Because of their degree of host-specificity, they may be particularly vulnerable to environmental change. Despite this, little is known about the host-plants and life histories of the Australian leaf-mining fauna. Here we present new information on the host-plant use of leaf-miners occurring in Australian subtropical rainforest. We repeatedly hand-collected leaf-miners at 14 sampling sites in the ‘Tweed Caldera’ subtropical rainforest region of south-eastern Queensland and north-eastern New South Wales, Australia. Leaf-miners and their host-plants were identified to species (or morphospecies in the case of some leaf-miners). Within the region, a total of 106 plant species was recorded as leaf-miner hosts, on which a total of 12 679 individual leaf-miners was counted, belonging to 50 different species. We measured the local host-plant range of each leaf-miner species for which we had reliable incidence records across sampling sites (24 species). Local host-specificity was relatively high with 66.7 % of species recorded from a single or two congeneric host-plants. 16.7 % of species were restricted to a single plant family and 16.7 % were recorded on a few to several plants of the same plant order or across a range of unrelated host-plants