SELECTION OF Plutella xylostella (L.) (LEPIDOPTERA: PLUTELLIDAE) TO CHLORFENAPYR RESISTANCE: HERITABILITY AND THE NUMBER OF GENES INVOLVED

Abstract

-The Plutella xylostella (L.) (Lepidoptera: Plutellidae) is a worldwide pest of Brassicaceae. Resistance has evolved against various insecticides including chlorfenapyr one of the most recently registered molecules to control this pest. The failure of chlorfenapyr to control this pest could be related to resistance in P. xylostella in the state of Pernambuco (Brazil), but there is currently no information on its heritability. Here, we estimated the heritability of resistance of P. xylostella to chlorfenapyr and the number of genes involved in the resistance in a field-derived population (PxClf-SEL). A field population was selected in the laboratory with increasing doses of chlorfenapyr (for five generations), and the LC 50s were estimated for every generation using the leaf dip bioassay. The selection increased resistance to chlorfenapyr in the PxClf-SEL as the LC 50 shifted from 27.6 (F 1 ) to 256.5 (F 5 ) mg chlorfenapyr/L. As a result, the resistance ratio (RR) increased from 33-fold (F 1 ) to 310-fold (F 5 ). The heritability of resistance of P. xylostella to chlorfenapyr was 0.90 (h 2 ), and the number of generations needed for a 10-fold increase in the resistance to chlorfenapyr was 5.20 (G). Other methods have shown different numbers of genes (0.64 and 1.88) involved in resistance of P. xylostella to chlorfenapyr. There was sufficient variation regarding resistance in the field population to account for a high realized heritability influenced mainly by additive genetic factors. Therefore, there is a high risk of chlorfenapyr resistance in the field.

Cross‐resistance and genetics of field‐evolved resistance to chlorfenapyr in Plutella xylostella

“…, 2016). The genetic analysis in the current study is not the first to be performed in P. xylostella , and is consistent with results from field‐collected populations or laboratory‐selected strains (Lima Neto & Siqueira, 2017; Wang et al. , 2019; Lima Neto et al.…”

“…Chlorfenapyr resistance was controlled by 1 major gene (Uesugi et al, 2002) or more than 1 gene (Van Leeuwen et al, 2004) in T. urticae, while that of O. hyalinipennis was associated with multiple genes (Ullah et al, 2016). The genetic analysis in the current study is not the first to be performed in P. xylostella, and is consistent with results from field-collected populations or laboratory-selected strains (Lima Neto & Siqueira, 2017;Wang et al, 2019;Lima Neto et al, 2020). The dominant resistance controlled by the monofactor could rapidly develop under continuous selection pressure in the field.…”

The emerging importance of noncoding RNAs in the insecticide tolerance, with special emphasis on Plutella xylostella (Lepidoptera: Plutellidae)

“…The diamondback moth displays resistance to more than 90 compounds, including new‐generation insecticides, which ranks it among the most insecticide‐resistant species in the world (Chandi & Singh, ). Biological features such as the short generation time, high fecundity, wide host range, and its resistance to insecticides are major factors which have led to the success of P. xylostella (Lima‐Neto & Abreu de Siqueira, ; Talekar & Shelton, ). In addition, this species is also capable of persisting in stressful environments such as, for example, cold conditions (Zhang et al, ).…”