laxmikant shinde

Mosquitoes have not only threatened human health but also adversely affect human and wild life as they act as vector for many deadly diseases. Among vector mosquito Aedes aegypti plays a key vector role to transmit viral diseases viz. Dengue, Zika, Yellow Fever and Chikunguniya. The present scenario for vector control strategies exposes the fact of rise in resistance index of mosquitoes against various available synthetic insecticides and also nonresponsive to bacterial larvicides. To overcome these circumstances, more emphasis should be given to bio-control strategies using secondary metabolites from plant extracts; since, they are enriched in bioactive components with larvicidal activity. Present study analyzed chemical composition and larvicidal efficacy of flowers of Gliricidia sepium and seeds of Annona squamosa in methanolic and hexane extracts. The bioassay for larvicidal activity was carried out using II, III, IV instar larvae of Aedes aegypti. It was observed that early ins...

Ineffectiveness of available nematicides and the high damage caused by plant-parasitic nematodes result in the urgent need to find some natural remedy for their control. Bioactivity of the pigment extracted from Serratia marcescens was screened for controlling nematodes at their juvenile stage. Test pigment was found effective against juvenile stages of Radopholus similis and Meloidogyne javanica at low concentrations (LC50 values, 83 and 79 μg/mL, respectively) as compared with positive control of copper sulphate (LC50 values, 380 and 280 μg/mL, respectively). The pigment also exhibited inhibition on nematode egg-hatching ability. Characterisation of extracted pigment with TLC, FTIR, HPLC, HPTLC and spectroscopic analysis confirmed the presence of prodigiosin as a bioactive metabolite. Considering the sensory mechanism of pathogen recognition by nematodes, the use of microbial secondary metabolites can be effective for nematode control rather than using whole organism.