Insects are one of the most species-rich groups of metazoan organisms. They play a pivotal role in most non-marine ecosystems and many insect species are of enormous economical and medical importance.
We examined the leaf transcriptome of galled and ungalled leaves of individuals of the Hawaiian endemic plant Metrosideros polymorpha (Myrtaceae) subject to infestation by psyllid (Hemiptera) gall-mak
