Correlation between Pesticide Resistance and Enzyme Activity in the Diamondback Moth,Plutella xylostella

Abstract

The diamondback moth, Plutella xylostella (L.) (Lepidoptera: Plutellidae), is one of the most important pests that has developed high pesticide resistance. The resistances of five Chinese populations of this moth, four resistant strains (from Beijing, Henan, Fujian, and Guangdong) and one susceptible strain, to five pesticides were determined, and the activities of carboxylesterase, glutathione S-transferase, and acetylcholine esterase were tested in all five populations. The correlations between pesticide resistance and enzyme activity were analyzed. The results showed that the resistance status to the five pesticides was different among the five populations. The resistance ratios of the Beijing and Henan populations to spinosad were 5.84 and 8.22, respectively, and those to beta-cypermethrin were 4.91 and 4.98, respectively. These ratios were higher than those for the Fujian and Guangdong populations. The Fujian population was more sensitive to abamectin and chlorpyrifos than the susceptible population (the resistance ratios were 0.14 and 0.91, respectively); in fact, the median lethal concentration for P. xylostella was significantly higher for chlorpyrifos than that for any of the other four pesticides. The carboxylesterase activity in P. xylostella showed positive correlations with the resistance to spinosad, beta-cypermethrin, chlorpyrifos, and abamectin, but no correlation was observed between the carboxylesterase activity and resistance to emamectin benzoate, between glutathione S-transferase activity and resistance to any of the five pesticides tested, or between acetylcholine esterase activity and any of the pesticides except for emamectin benzoate.

Toxicity and residual effects of insecticides on Ascia monuste and predator Solenopsis saevissima

“…Similarly, malathion (organophosphate) and methomyl (carbamate) act primarily to inhibit the enzyme esterase acetylcholinesterase (AChE) and thus should not be used subsequently in rotation. Thus rotating products with different active principles promotes an adequate pest management and can avoid problems such as a failure of pest control due to the emergence of insect resistance …”

“…Thus rotating products with different active principles promotes an adequate pest management and can avoid problems such as a failure of pest control due to the emergence of insect resistance. 27,29 Although the insecticides cartap, chlorfenapyr, deltamethrin, malathion and methomyl were effective at controlling A. monuste, none showed physiological selectivity in favor of the predator. Therefore, the use of these insecticides must be based on the principles of ecological selectivity.…”

Resistance Level of Plutella xylostella L. (Lepidoptera: Plutellidae) on Cypermethrin in the Regency of Kupang

“…The resistance level of P. xylostella larvae collected was different geographically, showed the natural variation among populations due to selection when those were exposured to insecticides (Siegfried et al, 2005). Gong et al (2013), stated that differences of ecological and environmental contributed to variation in enzyme activity among populations. For example, the increase of esterase activity was related to latitude.…”

Assessment of insecticides and Cry2AB toxin resistance development in Karnataka population of Plutella xylostella (Linn.)

“…esterases imparting resistance to organophosphates and indoxacarb (Sayyed and Wright (2006). CarE to spinosad which ultimately result in cross resistance and proving insecticidal rotational strategy to be vane (Gong et al, 2013). Though insecticides with diversity in their mode of action are evaluated for resistance over generations the core understanding of resistance mechanisms that are incurred due enzyme detoxification, target site insensitivity and cross resistance among the insecticidal groups are to be investigated further, owing to suitable substrates.…”