UTTAR PRADESH JOURNAL OF ZOOLOGY

Mosquitoes are considered as the dominant hematophagous insect which are responsible for transmitting various vector borne diseases such as Japanese encephalitis, Dengue fever, Malaria, Yellow fever, Chikungunya, Zika etc and majority of these horrible diseases will adversely affect the peoples inhabiting both tropical and subtropical regions. The existence of co-evolution between plants and insects influences the production of secondary plant compounds or extracts which retard the growth of these dreadful vectors. Such green insecticides are very effective and considering an important ecofriendly tool for eradicating the mosquitoes. These larvicidal activities are more feasible for vector control strategy as compared to artificial insecticides. The present study aimed to investigate the larvicidal activity of plant extract from the leaves of Catharanthus roseus, Lantana camara and Carica papaya against third and fourth instar stages of mosquito larvae. The healthy larvae were collected and tested with the mashed leaf extracts of different concentrations (1 mg/ml, 2 mg/ml and 3 mg/ml) for different exposure time such as 12, 24, 36, 48, 60, and 72 hours after which the mortality rate (%) of larvae were analysed. The percentages of larval mortality and standard deviations were calculated for each concentration of the leaf extracts. The results clearly indicated that the extract concentrations of both Catharanthus roseus and Lantana camara showed highest mortality rate (100%) than Carica papaya at the end of 72 hour of exposure. The variations exhibited in the mortality rates of Carica papaya were 43.33%, 63.33% and 86.66% in 1mg/ml, 2mg/ml and 3 mg/ml of leaf extracts respectively. Leaf extracts from Catharanthus roseus and Lantana camara indicated its potential larvicidal efficacy against mosquito larvae. The outcome of the study specified that the leaf extracts have a significant role for monitoring and regulating the vector borne mosquito larvae with an ecofriendly and effective manner.