Mosquito larvicidal and silver nanoparticles synthesis potential of plant latex

Silver nanoparticles (AgNPs) were synthesized from the latex of the medicinally important plants Euphorbia milii, Euphorbia hirta, Ficus racemosa and Jatropha curcas. Synthesized AgNPs were characterized by UV-Vis spectrophotometry, scanning electron microscopy, energy dispersive X-ray analysis, X-ray diffraction, Fourier transformed infrared spectroscopy, particle size, and zeta potential analysis. Potency of latex and latex-synthesized AgNPs was evaluated against the 2nd and 4th instar larvae of Aedes aegypti and Anopheles stephensi. The lowest lethal concentration 50 (LC50) value among the different types of plant latex studied was observed for latex of E. milii (281.28±23.30 and 178.97±37.82 ppm, respectively) against 2nd instar larvae of Ae. aegypti and An. stephensi. E. milii latex-synthesised AgNPs showed a high reduction in LC50 compared with its latex; i.e., 8.76±0.46 and 8.67±0.47 ppm, respectively, for 2nd instars of Ae. aegypti and An. stephensi. LC50 values of AgNPs synthesized using the latex of E. hirta, F. racemosa and J. curcas were lower than those of the latex of the respective plants; i.e., 10.77±0.53, 9.81±0.52, 12.06±0.60 and 8.79±0.51, 9.83±0.52, 9.60±0.51 ppm, respectively, for 2nd instars of An. stephensi and Ae. aegypti. Similarly, as compared with the plant latex, lower LC50 values were reported for latex-synthesized AgNPs against 4th instars of Ae. aegypt and An. stephensi. Results showed that all the types of plant latex investigated have the potential to convert silver nitrate into AgNPs showing a spectrum of potent mosquito larvicidal effects, indicating the possibility of further exploration of the bioefficacy of latex and latex-synthesized AgNPs against vectors of public health concerns