Oviposition patterns and larval damage by the invasive horse‐chestnut leaf miner Cameraria ohridella on different species of Aesculus

Preference–performance relationships are thought to be particularly important for sessile herbivores, such as leaf miners, whose choice of host plant is entirely determined by the ovipositing female. However, this relationship has seldom been examined between a non‐native herbivore and non‐native host plants. Leaf damage and oviposition patterns by the invasive horse‐chestnut leaf miner, Cameraria ohridella D eschka & D imic, 1986 ( L epidoptera: G racillariidae), were investigated on 11 different species of Aesculus L . ( S apindaceae) at the R oyal B otanic G ardens, K ew. The tree species studied were of different continental origin and belonged to four different sections of the genus Aesculus . Oviposition was recorded on all the investigated species of Aesculus , with egg densities being greatest on Aesculus hippocastanum L . and Aesculus turbinata B lume. By contrast, mines were formed on only six out of the 11 studied species. There was a positive correlation between eggs laid on leaves of a species and levels of leaf tissue damage by C. ohridella , although eggs were laid on species on which larvae did not develop. Host suitability for C. ohridella was related to the phylogeny of the genus Aesculus . Species belonging to the section Aesculus were susceptible to the leaf miner; species in the section Pavia showed variable susceptibility; and species in the section Calothyrsus and Macrothyrsus were found to be resistant.