Realized heritability and risk assessment of resistance of Plutella xylostella to tolfenpyrad

To evaluate the resistance risk of diamondback moth( Plutella xylostella) to tolfenpyrad and to provide positive guidance for scientific application of tolfenpyrad,P. xylostella were selected in the laboratory for resistance to tolfenpyrad. The realized resistance heritability and generations holding a 10-time increase in LC50 were evaluated based on the Tabashniku0027s method( threshold trait analysis). The realized resistance heritability( h2) was 0. 124 9 for F0- F13and0. 184 3 for F16- F26,during which there were a total of 2 generations without selection. The realized resistance heritability for the entire selection period was 0. 167 2,according to which it would take 15. 0 ~ 6. 8 generations for P. xylostella to develop 10-time resistance to tolfenpyrad under selection pressure of 50%- 90% mortality for each generation. These results indicated that P. xylostella may have significant resistance risk to tolfenpyrad.