Unravelling survivorship: Physiological and biochemical insights into Jatropha seed oil toxicity against immature stages of Aedes aegypti (L.) (Diptera: Culicidae)

Jatropha seed oil, renowned for its biofuel value and rich composition of bioactive constituents, has long been recognized for its pesticidal potential, yet its role as a mosquitocidal intervention against immature stages remains insufficiently characterized. In the present study, eggs, 3rd instar larvae, and pupae of Aedes aegypti were treated with graded concentrations of Jatropha seed oil, and survivorship patterns were assessed using Kaplan-Meier estimators and Cox proportional hazards regression. Egg hatching probability showed moderate inhibition at intermediate doses (80–85 ppm), while larval survivability declined in a clear concentration-dependent manner, with 350 ppm significantly accelerating mortality and reducing overall survival time (HR=4.10, p < 0.0001). Pupae were less sensitive, but higher concentrations (≥650 ppm) significantly shortened survival, with 800 ppm reducing survival to ∼12 % by 50 h. Morpho-histological examinations revealed disruption of midgut epithelial integrity, cuticular deformities, and developmental abnormalities across immature stages, corroborating toxic stress at tissue level. FTIR and Raman spectra confirmed the presence of phorbol esters, triglycerides, and other bioactive phytochemicals providing a biochemical basis for the observed toxicity. Overall, the findings demonstrate that Jatropha seed oil profoundly alters survivorship dynamics of Ae. aegypti in a stage and dose-dependent manner, highlighting its potential as a bio-intensive alternative for vector management while underscoring the need for further work on suitable formulations and ecological safety.