Efficacy of Adhatoda zeylanica Medik. leaf as mosquito repellent

Herbal products are cheaper and effective than chemical based mosquito repellent, therefore an attempt has been made to prepare a 100 % herbal product based on traditional practices and rural wisdom. Present study was conducted for effective utilization of Basak (Adhatoda zeylanica Medik. syn. A. vasica Nees) as a mosquito repellent. Seven varieties of products were prepared from its leaves with different natural compositions. Study results revealed that maximum percentage of weight loss with V7 variety followed by V1 and lowest in variety V6. Almost all varieties of bio-cake burned within 35 – 45 minutes except variety V5, which took 60 minutes to complete burning. Variety V6showed highest ash content (7.70 g) and lowest ash was recorded for V5 (1.67 g) after complete burning. The emission of CO2, CO and O3was recorded as V2>V4>V3>V5 ≈ V7>V1>V6; V5>V6>V1>V7>V4>V2>V3 and V5>V3 ≈ V4 ≈ V7>V2>V1>V6, respectively during burning of bio-cake. On the other hand knock down experiment demonstrated that almost all varieties of bio-cakes are effective as mosquito repellent. But only two varieties (V6 and V7) caused more than 50 % knock down. Finally the emission of gaseous product was compared with a synthetic mosquito coil