Background: Aedes aegypti is a primary vector of dengue, chikungunya, and Zika viruses. Plant-derived mosquitocidal agents offer an eco-friendly alternative to synthetic chemicals. This study evaluated the phytochemical composition and mosquitocidal activity of Calophyllum inophyllum methanol leaf extract against Aedes aegypti.

Methods: Preliminary phytochemical analysis was conducted using standard qualitative tests. Ovicidal activity was assessed by exposing eggs to various concentrations (100–500 µg/mL). Larvicidal and pupicidal activities were evaluated against first to fourth instar larvae and pupae using five concentrations (100–500 µg/mL) with five replicates. Mortality data were subjected to probit analysis to determine LC₅₀ and LC₉₀ values.

Results: Phytochemical screening revealed the presence of phenolics, alkaloids, saponins, steroids, tannins, flavonoids (strong positive), and terpenoids, while quinones were absent. The extract exhibited concentration-dependent ovicidal activity, with egg hatchability reducing from 80.6% at 100 µg/mL to 6.2% at 400 µg/mL, and complete inhibition at 500 µg/mL. Larval mortality increased with concentration and decreased with developmental stage. The LC₅₀ values ranged from 248.6 µg/mL (first instar) to 390.8 µg/mL (pupae). The highest susceptibility was observed in first instar larvae, while pupae were most tolerant.