Essential oils and extract of Curcuma longa, ar-turmerone, and curcuminoids were evaluated for their larvicidal and deterrent activity against mosquitoes. Ar-turmerone and curcuminoids constituted 36.9, 24.9 and 50.6% of rhizome oil, leaf oil, and rhizome extract, respectively. Ar-turmerone was the major compound of the rhizome oil (36.9%) and leaf oil (24.9%). The ethanolic extract had 15.4% arturmerone with 6.6% bisdesmethoxycurcumin, 6.1% desmethoxycurcumin, and 22.6 % curcumin. In in vitro studies, essential oils of the leaf (biting deterrence index [BDI] = 0.98), rhizome (BDI = 0.98), and rhizome ethanolic extract (BDI = 0.96) at 10 μg/cm² showed biting deterrent activity similar to DEETat 25 nmol/cm² against Aedes aegypti L. Among the pure compounds, ar-turmerone (BDI = 1.15) showed the biting deterrent activity higher than DEETat 25 nmol/cm² whereas the activity of other compounds was lower than DEET. In Anopheles quadrimaculatus Say, only ar-turmerone showed deterrent activity similar to DEET. In dose—response bioassay, ar-turmerone showed significantly higher biting deterrence than DEETat all the dosages. Ar-turmerone, at 15 nmol/cm², showed activity similar to DEET at 25 nmol/cm² and activity at 5 nmol/cm² was similar to DEETat 20 and 15 nmol/cm². Leaf essential oil with LC₅₀ values of 1.8 and 8.9 ppm against larvae of An. quadrimaculatus and Ae. aegypti, respectively, showed highest toxicity followed by rhizome oil and ethanolic extract. Among the pure compounds, arturmerone with LC₅₀ values of 2.8 and 2.5 ppm against larvae of An. quadrimaculatus and Ae. aegypti, respectively, was most toxic followed by bisdesmethoxycurcumin, curcumin, and desmethoxycurcumin.