Stress Treatment

Early fourth instar larvae of C. ramosus were used for all the experimental work. Larvae were desiccation treated in a desiccator chamber (<5% relative humidity) on a dry tissue paper placed in a glass petri plate. For starvation stress, larvae were kept in petri plates without any nutrients. For heat stress, we kept the larvae in petri plates along with nutrient medium (Bomble and Nath 2019) inside the incubator at 40 °C. For combinatorial stress treatment, larvae were exposed to two different stressors concurrently viz. desiccation with heat, heat with starvation, desiccation with starvation. LT₂₀ (lethal time required for 20% mortality in the population) values were taken as an end point for each experiment. (Supplementary data, Table: 1-6). In subsequent text, following abbreviations are used viz. Desiccation Stress (DS), Heat Stress (HS), Starvation Stress (SS), Desiccation with Heat stress (D+H), Heat with Starvation (H+S), Starvation with-Desiccation (D+S). Since various parameters of stress response manifested starting with LT₂₀ doses (for D, H, S, D+S, H+S, D+H, MS), we chose LT₂₀ as the base-level parameter for all treatments. LT₂₀ values were used for all the experiments carried out to compare between effect of stressors administered either as a singular and or in a combinatorial form. All the experiments were replicated thrice per treatment and were carried out under laboratory conditions.