The impact of salinity on plant-insect interactions
Research Poster Health & Life Sciences 2025 Graduate ExhibitionPresentation by Sahil Pawar
Exhibition Number 180
Abstract
The progressive salinization of cultivable land, an abiotic stress, poses a major problem for tomato production. Additional pressures by a biotic stress - insect herbivory by caterpillars, can cause further yield losses. A huge body of literature details the negative effects of salt stress and insect herbivory on plants. But how are insect herbivores affected by the rising salinity? My research aims to investigate the effects of salt on the tomato fruitworm Helicoverpa zea, its parasitoid wasp Microplitis croceipes, and the predatory ladybeetle Harmonia axyridis. We find that H. zea moths lay fewer eggs on salt-treated plants while H. zea larval growth rate decreases in a dose-dependent manner with increasing salt concentration. We also find that the effects of salt stress can cascade across trophic levels negatively impacting insect herbivores as well as their natural enemies. More specifically, parasitoid wasps show delayed development in salt-treated larvae or"salty" larvae, whereas predatory ladybugs prefer to consume more salty larvae than non-salty larvae. Our research provides essential information to help devise IPM strategies in areas affected by abiotic and biotic stresses.
Importance
Our research provides essential information to help devise Integrated Pest Management (IPM) strategies for plants growing in areas affected by soil salinization and insect herbivory.