
The larvicidal activity of Sida acuta was evaluated against 3rd instars larvae of Anopheles subpictus and Culex tritaeniorhynchus. The crude leaf extract and active compound cryptolepine showed negligible mortality against early third instar larvae of An. subpictus and Cx. tritaeniorhynchus. The 24 h LC50 value was observed at 38.68, 50.81 mg/l and 9.98, 12.69 mg/l for crude leaf extract and active compound cryptolepine, respectively. The structure was elucidated from infrared, ultraviolet, 1H-Nuclear Magnetic Resonance, 13C-NMR, and mass spectral data.