AUTHOR(S)
G. Durga Devi* K. Murugan and C. Panneer Selvam

ABSTRACT

Biosynthesis of insecticides from plant extractsis currently under exploitation. Plant extracts are very cost effective andeco-friendly and thus can be an economic and efficient alternative for thelarge-scale synthesis of synthetic and other chemical insecticides. So thepresent study was carried out to establish the larvicidal effect of synthesizedsilver nanoparticles (AgNPs) using leaf extract of Euphorbia hirta (Euphorbiaceae)against the first to fourth instar larvae and pupae of the crop pest of cottonboll worm , Helicoverpa armigera. The production of the AgNPssynthesized using leaf extract of Euphorbia hirta was evaluated througha UV–Vis spectrophotometer in a wavelength range of 200 to 700 nm. An SEMmicrograph showed 30-60-nm-size aggregates of spherical- and cubic-shapednanoparticles. EDX showed the complete chemical composition of the synthesizednanoparticles of silver. The results showed that the considerable larvalmortality was found in the synthesized AgNPs against the I instar to IV instarlarvae and pupae of Helicoverpa armigera. The leaf extract exhibitedlarval toxicity against the I instar to IV instar larvae and pupae of Helicoverpaarmigera. The chi-square value was significant at p<0.05 level.Nanoparticle treatment showed toxicity against larval instars of Helicoverpaarmigera and had impact on the biological parameters of Helicoverpaarmigera. Treated larva and pupa showed extended their durations.Similarly, longevity of male and female and fecundity also reduced. Treatedinsects had less consumption index at growth. Decreased food utilizationefficiency measures (ECI and ECD) and concomitant decreased in the level ofdigestive enzyme profiles in the midgut after the treatment indicate thatnanoparticle administration affected gut physiology of insects.

DOI
https://doi.org/10.57182/jbiopestic.7.0.54-66

PAGES: 54-66 | 15 VIEWS | 9 DOWNLOADS

DOWNLOAD FULL ARTICLE