Comparison Of Three Administration Methods (Orally, Microinjection And Spraying Through Skin Contact) Of Scorpion Venom Against Stem Borer (Sesamia nonagrioides (Lepidoptera: Noctuidae))

Polyphagous Sesamia nonagrioides (Lepidoptera: Noctuidae) is an important pest of sugarcane in Khuzestan province. This study aimed to evaluate the toxicity effects of Hottentotta Saulcyi scorpion venom on S. nonagrioides using three methods; orally, microinjection and spraying through skin contact. After the venom collection and measuring the protein content of the venom, different venom doses were prepared. larvae were injected with five doses of venom (0.15µg, 0.35µg, 0.5µg, 0.75µg and 1µg; fifteen larvae per each dose) and the mortality percentage were recorded during the experiment. Finally, lethal doses (LD50 and LD100) and toxicity unit (TU) were calculated using Probit analysis. According to the results, S. nonagrioides was affected by the toxicity of scorpion venom. LD50, LD100 and TU values for stem borer larvae at 24h was obtained 0.96, 2.23 µg/mg and 104.17 respectively. This study demonstrated that injection of H. Saulcyi venom immediately causes locomotive paralysis and then death in all larvae injected by high doses of scorpion venom (1µg and 0.75µg) after 48h. The effect of orally and spraying through skin contact administration of different doses of scorpion venom in stem borer mortality were not statically significant. The results of this study indicated that the scorpion venom was effective in the injection method while larvae showed resistance to spraying and oral administration of the venom.