Balancing Efficacy, Toxicological Selectivity and Yield Response of Insecticides Against the Invasive Spiralling...

The spiraling whitefly, Aleurodicus dispersus Russell, is an invasive and polyphagous pest posing a serious challenge to eggplant production in tropical agroecosystems, with increasing relevance across warm regions worldwide, where insecticide use can result in unintended toxicological effects on nontarget arthropods. Field experiments were conducted over two consecutive cropping seasons using a randomized block design with three replications to evaluate the efficacy and toxicological selectivity of nine commonly used insecticides against A. dispersus, with particular emphasis on impacts on aphelinid parasitoids (Encarsia spp.) and key arthropod predators (Cybocephalus sp., Mallada astur and Scymnus coccivora) and fruit yield under field-relevant exposure conditions. Insecticide applications significantly affected posttreatment whitefly abundance, parasitism (general, unidentified) and predator populations, with treatment effects consistently exceeding seasonal effects. Per cent reduction analyses revealed pronounced differences among insecticides in both whitefly suppression (48.2%-89.6%) and nontarget toxicity. Acetamiprid, buprofezin and thiamethoxam exhibited relatively higher toxicological selectivity, whereas acephate, thiacloprid and thiodicarb showed broader nontarget impacts. Univariate (ANCOVA/ANOVA-based) analyses identified clear treatment-wise differences, while multivariate analyses integrating target and nontarget responses clearly distinguished insecticides with relatively selective toxicological profiles from broad-spectrum compounds, supported by selectivity and field safety indices. Fruit yield differed significantly among treatments (18.5-30.8 t ha^-1) but not between seasons, and higher yields were generally associated with effective whitefly suppression combined with reduced nontarget impacts. Insecticides exhibiting favourable efficacy-selectivity trade-offs produced stable yield advantages across seasons. These findings demonstrate that insecticide performance against A. dispersus in eggplant is best assessed through integrative (combined univariate and multivariate), field-based toxicological frameworks rather than pest mortality alone, providing field-based evidence to inform aware insecticide selection applicable across vegetable production systems.