Genetics and evidence for an esterase‐associated mechanism of resistance to indoxacarb in a field population of diamondback moth (Lepidoptera: Plutellidae)

Abstract

Bioassays (at generation G2) with a newly collected field population (designated CH3) of Plutella xylostella L. from farmers' fields in the Cameron Highlands, Malaysia, indicated resistance ratios of 813-, 79-, 171-, 498- and 1285-fold for indoxacarb, fipronil, spinosad, deltamethrin and Bacillus thuringiensis toxin Cry1Ac respectively compared with a laboratory susceptible population (Lab-UK). At G2 the field-derived population was divided into two subpopulations: one was selected (G2 to G7) with indoxacarb (indoxa-SEL), while the second was left unselected (UNSEL). A significant reduction in the resistance ratio for each compound was observed in UNSEL at G8. For indoxa-SEL, bioassays at G8 found that selection with indoxacarb gave a resistance ratio of 2594 compared with Lab-UK and of 90 compared with UNSEL. The toxicity of fipronil, spinosad and deltamethrin was not significantly different in indoxa-SEL at G8 compared with G2 but was significantly greater than UNSEL at G8. The toxicity of Cry1Ac was significantly reduced in indoxa-SEL at G8 compared with G2 but was also significantly greater than UNSEL at G8. This suggests that indoxacarb selection maintained resistance to these compounds in the indoxa-SEL population. Synergist studies indicated that resistance to indoxacarb in indoxa-SEL was esterase associated. Logit regression analysis of F1 reciprocal crosses between indoxa-SEL and Lab-UK indicated that resistance to indoxacarb was inherited as an autosomal, incompletely recessive (D(LC) = 0.35) trait. Tests of monogenic inheritance suggested that resistance to indoxacarb was controlled by a single locus.

Induction and Transmission of Tolerance to the Synthetic Pesticide Emamectin Benzoate in Field and Laboratory Populations of Diamondback Moth

“…Esterases are frequently implicated in the resistance of insects to organophosphates, carbamates, and pyrethroids (Hemingway andRanson 2000, Srigiriraju et al 2009). In a previous study, the resistances to organophosphate and indoxacarb pesticides were found to be positively correlated with an increase in esterase activity (Doichuanngam and Thornhill 1989;Sayyed and Wright 2006), which is congruent with our study. It has also been reported that an abamectinresistant strain of P. xylostella had notably enhanced MFO activity (Qian et al 2008).…”

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

“…The heritability of chlorfenapyr resistance estimated here was higher than those observed with flubendiamide (h 2 = 0.15) (YAN et al, 2014), chlorantraniliprole (h 2 = 0.26) (GONG et al, 2014), spinosad (h 2 = 0.02) (SAYYED; WRIGHT, 2006), indoxacarb (h 2 = 0.40) (NEHARE et al, 2010) and Bacillus thuringiensis subsp. kurstaki (h 2 = 0.19) and Bacillus thuringiensis subsp.…”

“…The short generation time, high fecundity and broad host usage within Brassicaceae as well as its remarkable ability to rapidly evolve insecticide resistance are among these factors (TALEKAR; SHELTON, 1993;SAYYED et al, 2008). Several field populations of P. xylostella have evolved resistance to novel insecticides including chlorantraniliprole (RIBEIRO et al, 2014), spinosad (SAYYED; WRIGHT, 2006) and indoxacarb (NEHARE et al, 2010). Nearly two decades ago, the annual cost of controlling P. xylostella on a worldwide basis was estimated to be US$ 1 billion.…”

Insecticide resistance in populations of the diamondback moth, Plutella xylostella (L.) (Lepidoptera: Plutellidae), from the state of Pernambuco, Brazil

“…The Bezerros County population still exhibited moderate and high resistance to indoxacarb and abamectin, respectively. The moderate level of resistance (RR = 25.3 times) to indoxacarb was lower than that observed by Sayyed & Wright (2006) in the Cameron Highlands, Malaysia. The resistance to indoxacarb in Bezerros population is possibly associated with its frequent use, despite the rotation usually adopted with methomyl-and B. thuringiensis-based products.…”