Larvicidal effect of carica papaya leaf extract against aedes mosquitoes
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Date
2019-09-12
Authors
Karunarathne, R. R.
Noordeen, F.
Journal Title
Journal ISSN
Volume Title
Publisher
University of Peradeniya
Abstract
Dengue is an acute viral infection transmitted by infected Aedes aegypti and Aedes albopictus mosquitoes causing dengue fever or dengue haemorrhagic fever. Vector control is the most effective way to control dengue. Chemical larvicides are toxic to the environment and intense use leads to development of resistance. The best larvicides would be safe and eco-friendly bio-products. The objective of the present study was to test the anti-Aedes activity of C. papaya leaf extract against larvae of Ae. aegypti and Ae. albopictus. Fresh leaves of C. papaya were ground well without adding any water, squeezed and filtered to obtain a pure fresh leaf extract. Different amounts of distilled water were mixed with pure leaf extract to prepare different concentrations and tested against the fourth instar larvae of Ae. aegypti and Ae. albopictus. Following the treatment with C. papaya leaf extracts, number of dead larvae was recorded at every 12 hours for 48 hours. Percentage larval mortality and LC₅₀, LC₉₀ values were calculated to evaluate the larvicidal activity at different concentrations of C. papaya leaf extract. Pure leaf extract of C. papaya showed a larvicidal activity against the fourth instar larvae of Ae. aegypti and Ae. albopictus. One hundred percent mortality was observed for the larvae of Ae. aegypti and Ae. albopictus within 12 hours at the highest concentration of C. papaya leaf extract treatment, 20% (v/v). For Ae. aegypti, the LC₅₀ and LC₉₀ values were 5.57% (v/v) and 10.29% (v/v), respectively. For Ae .albopictus, the LC₅₀ and LC₉₀ values were 5.53% (v/v) and 12.09% (v/v), respectively. In conclusion, C. papaya leaf extract showed larvicidal activity against the fourth instar larvae of, Ae. aegypti and Ae. albopictus at different concentrations.
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Keywords
Dengue , C. papaya leaf extract , Larvicidal activity