Assessment of Resistance Risk to Emamectin Benzoate,Indoxacarb and Spinetoram in Cotton Leaf Worm, Spodoptera littoralis (Boisd.)

Document Type : Original Article

Authors

1 Department of Standard Rearing, Central Agricultural Pesticides Laboratory, Agriculture Research Center, 12618 Giza, Egypt

2 Cotton Pesticides Bioassay Dept., Plant Protection Res. Institute, ARC

3 Cotton leaf worm Dept., Plant Protection Res. Institute, ARC

Abstract

Cotton leaf worm, Spodoptera littoralis is a major polyphagous pest in Egypt. Resistance development to conventional insecticides led to introduce new pesticides with novel modes of action such as emamectin benzoate, indoxacarb and spinetoram. Assessment risk of resistance evolution to these insecticides has a great important for evaluating their future use on a pest population. To determine suitable larval stage for selection experiment. Bioassays were carried out against 1-st, 3-ed and 5-thlarval instars. Resistance risk assessment to these insecticides was conducted by selecting a field collected population of S. littoralis (1-stinstar) with the tested insecticides in the laboratory for six generations to estimate their realized heritability (h2). Realized heritability (h2) of resistance was 0.21, 0.37 and 0.33 for emamectin benzoate, indoxacarb and spinetoram, respectively. The rates of resistance development were compared using the response quotient (Q), which was estimated as 0.170 for both emamectin benzoate and spinetoram; while indoxacarb recorded Q value of 0.21. The projected rate of resistance development had been estimated with different values of slopes and realized heritability. Results suggest that a risk for resistance development to emamectin benzoate, indoxacarb and spinetoram may occur in S. littoralis under continuous selection pressure but that resistance development would be slower against emamectin benzoate and spinetoram than indoxacarb.

Keywords

Files

Share

How to cite

Statistics