The diamondback moth, Plutella xylostella (L.), is a major pest of cruciferous crops worldwide, and the widespread evolution of resistance to conventional insecticides has intensified interest in safer, plant-derived alternatives for its management. In the present study, hexane extracts of six plant species viz., Azadirachta indica, Nerium oleander, Plumeria rubra, Sesbania grandiflora, Swietenia macrophylla, and Tagetes erecta obtained through Soxhlet extraction were evaluated at 5% concentration for larvicidal toxicity, effects on larval weight, and growth indices against P. xylostella under laboratory conditions, with azadirachtin 1% EC (2 ml/l) as a treated check and solvent and untreated checks for comparison. All extracts exhibited significant toxicity relative to the checks at 24 hours, with S. grandiflora and S. macrophylla recording the highest mortality among the extracts (46.67% and 43.33%, respectively) at 48 hours, on par with the treated check (43.33%) by 72 hours, S. grandiflora achieved 53.33% mortality, close to the treated check (63.33%). Larval weight gain was markedly suppressed in these two extracts, with larvae weighing only 0.85 mg (S. grandiflora) and 1.30 mg (S. macrophylla) on day 10, compared to 4.26 mg in the untreated control, and both treatments showed a one-day extension of larval duration, pupating on day 13 versus day 12 for the control. Growth index analysis further confirmed their superior bioefficacy, with larval growth indices of 2.51 (S. grandiflora) and 2.77 (S. macrophylla) against 9.39 in the untreated control, along with correspondingly lower suitability indices and higher antibiosis indices. Overall, the findings identify S. grandiflora and S. macrophylla hexane extracts as promising botanical candidates, with toxicity and growth-inhibitory effects approaching those of the standard azadirachtin check, warranting their further exploration as eco-friendly components of integrated pest management programs against P. xylostella.