I study the preference and performance of specialized herbivorous insects on C4 vs. C3 host plants in harsh environments. I document the vigor of plants under field and greenhouse conditions in terms of growth rate, photosynthesis rate and water use efficiency, in order to characterize their putative appeal to endogenous herbivores as predicted by the plant vigor hypothesis. My research focuses on the gall midge Dasyneuriola prolifica on its main C4 host-plant Suaeda fruticosa and the non-host C3 plant Suaeda palaestina. The two plants grow in sympatry in the Jordan Valley area and both are available for the midge, but galls are known only from S. fruticosa.

I conduct manipulative experiments to test if changes in plant vigor parameters can render an ignored C3 plant attractive and suitable for development of the gall-midge as manifested by female oviposition choice, larval performance, and adult fitness. The more general context of my study is exploring whether the current pattern of host-plant use in a major lineage of herbivorous insects is shaped by ecological rather than merely geographical availability of potential host plants.