Which impatiens is eaten more? Phytoliriomyza melampyga (Agromyzidae) attack rates on invasive Impatiens glandulifera and I. parviflora and native I. noli-tangere

Invasive plants are often released from herbivore pressure in their secondary range, but native herbivores can adapt to feed on them over time. Impatiens glandulifera and I. parviflora are two invasive species, whose leaves in the secondary range have been severely damaged by leaf miners in recent years. The leaf miner attack rates for these species and a native congener, I. noli-tangere , were examined. Molecular analysis shows that all three impatiens species are affected by the same leaf miner Phytoliriomyza melampyga (Agromyzidae) without signs of divergence between populations living on different plant species. The native I. noli-tangere is more often damaged by the leaf miner, whilst I. parviflora is attacked more often than I. glandulifera . The largest mined area was found in I. glandulifera leaves and the smallest in I. noli-tangere . The nitrogen content, indicative of food quality, was similar in all three species, and there were no differences in 15 N enrichment between miners from three impatiens species. We suppose that observed differences in attack rates and mined area in P. melampyga on three Impatiens species can be explained mainly by different levels of antiherbivore defence and recent host shift from native species to invasive ones.