Larvicidal Effects Of Pongamiaglabra and Syzygiumaromaticum On Aedes Aegypti Mosquito Larvae

Abstract

Mosquitoes are considered as the most nuisance causing vectors as they are responsible for a widespread of diseases.  Malaria-borne  mosquitoes  are responsible  of killing  two  to three  million  people  and infect  an estimated  two hundred million or more annually. A host of other mosquito-borne diseases including filariasis, yellow fever, dengue, and encephalitis  kill  and  debilitate  hundreds  of  millions  more.  The  present  study  investigates  the  bio  efficacy  of  two commercially  available plant oils from Pongamia glabra (Karanja) and Syzygium aromaticum (Clove). These two plant oils were tested against Aedes aegypti (Dengue fever mosquito) to determine their lethal concentration doses (LC50). A larval toxicity assay was performed where a stock solution of 10% was prepared for both the oils at a concentration range of 100 to 900 ppm and 90 to 1300 ppm was set for Pongamia glabra and Syzygium aromaticum respectively. A batch of each 10 IVth  instar larvae was subjected to the assay with test, combination and a control set for a period of 24 and 48 hrs. LC50 of two oils were determined while the combination of two oils showed a synergistic effect. The effect of P. glabra and S. aromaticum on the anterior and posterior regions of the midgut region of A. aegypti larvae were found damage to epithelial cells,  basement  membrane,  peritrophic  membrane,  fat  body  cells  and  nuclei  were  observed.  The  results  of  the  study showed  that  the synergistic  method  of using common  eco-safe  combination  of plant  oils were effective  to handle  and monitor A. aegypti larva. Pongamia glabra and Syzygium aromaticum are among the successful mosquito control agents.