Cross‐resistance, mode of inheritance, synergism, and fitness effects of cyantraniliprole resistance in Plutella xylostella

Abstract

The diamondback moth, Plutella xylostella (L.) (Lepidoptera: Plutellidae), has evolved resistance to various types of insecticides in the field. In the present study, the resistance of P. xylostella (designated Cya-SEL) to cyantraniliprole increased to 30.6 and 326-fold after 26 generations of selection, compared with the field population (TA) and susceptible population (LAB), respectively. The resistant population also had developed low to moderate levels of resistance to abamectin (3.3-fold), flubendiamide (14.1-fold), and chlorantraniliprole (24.3-fold). Synergism tests indicated that piperonyl butoxide (PBO) and diethyl maleate (DEM) increased the toxicity of cyantraniliprole in the selected strain, i.e., synergism ratio was 2.8 and 3.3-fold, respectively. Reciprocal crosses were made between the susceptible (LAB) and resistant strain collected from Zengcheng (ZC). The degree of dominance and overlapping confidence intervals of LC 50 values of F1 progenies (ZC♀ 9 LAB♂ and LAB♀ 9 ZC♂) suggested an autosomal and incompletely recessive mode of resistance to cyantraniliprole. The test of monogenic inheritance based on a backcross of F1 progeny with the ZC population indicated that resistance to cyantraniliprole was controlled by multiple genes. Additionally, Cya-SEL had a lower reproductive ability and relative fitness than the other tested populations. These findings provide useful information for effective resistance management strategies against P. xylostella.

Fitness costs and life table parameters of highly insecticide‐resistant strains of Plutella xylostella (L.) (Lepidoptera: Plutellidae) at different temperatures

“…the non-selected population and the susceptible laboratory strain. 14 In summary, we observed significant fitness costs in strain Sudlon-Tfm, which was found to be highly resistant to both diamide and BPU insecticides when compared with strain Sudlon at all three temperatures. Both strains share the same genetic background, and therefore we associate these fitness costs with the genetic processes involved in BPU resistance.…”

“…Finally, it was recently demonstrated that a cyantraniliprole‐resistant strain of DBM displayed an overall lower reproductive ability and relative fitness than the two reference strains, i.e. the non‐selected population and the susceptible laboratory strain …”

“…Moreover, negative genetic trade‐offs can also be apparent in the absence of the insecticide or in the presence of sublethal doses . In P. xylostella , fitness costs have been shown to be a direct consequence of diamide resistance, which, for example, resulted in a decline in the overall fitness in a cyantraniliprole‐selected laboratory strain, with negative effects on developmental time of larvae, rate of pupation, adult emergence and fertility . On the other hand, fitness costs can also be absent, as seen in the housefly, Musca domestica , where a fitness advantage was observed for kdr mutatation in the voltage‐gated sodium channel …”

“…10,11 In P. xylostella, fitness costs have been shown to be a direct consequence of diamide resistance, 12,13 which, for example, resulted in a decline in the overall fitness in a cyantraniliprole-selected laboratory strain, with negative effects www.soci.org D Steinbach, G Moritz, R Nauen on developmental time of larvae, rate of pupation, adult emergence and fertility. 14 On the other hand, fitness costs can also be absent, as seen in the housefly, Musca domestica, where a fitness advantage was observed for kdr mutatation in the voltage-gated sodium channel. 15 Zhang et al 5 investigated the temperature effects on organophosphate (OP)-resistant DBM strains and concluded that extremely cold or warm conditions are unfavourable for insect development and may also modify the fitness costs associated with pesticide resistance.…”

Field survey of ryanodine receptor mutations (G4946E and I4790K) and their effects on biotic performance in the diamondback moth

“…12) A strain with cyantraniliprole resistance conferred by multiple genes showed reduced reproduction compared to reference strains without insecticide selection. 14) However, no data on biotic performances are available for a cyantraniliprole-resistant strain in which resistance is fundamentally conferred by I4790K.…”