Epacromius coerulipes is a widely distributed locust pest species. Chemical control is the main method used to kill locusts; however, this can result in the selection of locusts with resistance to chemical pesticides. Therefore, the study of resistance is of great significance for the sustainable management of locusts. In this study, to investigate the relationship between detoxification enzymes and butene‐fipronil resistance in E. coerulipes, resistant strains of the locust were compared with sensitive strains. The synergism of synergistic agents was significantly enhanced, and the activities of multifunctional oxidase, carboxylesterase, and glutathione sulfur transferase were significantly increased. Transcriptome sequencing revealed 226 detoxification enzyme genes and 23 upregulated genes. Neighbor‐joining was used to construct a phylogenetic tree of related gene families, which included 59 P450 genes, 52 carboxylesterases (CarE) genes, and 25 glutathione S‐transferase (GST) genes. Reverse transcription polymerase chain reaction (RT‐PCR) analysis results of overexpressed genes in the resistant population combined with a phylogenetic tree showed that four P450 genes belonged to the CYP6, CYP4, CYP18 and CYP302 families, two CarE genes belonged to Clade A families, and one GST gene belonged to the Sigma family. These family members were annotated as detoxification enzyme genes of metabolic insecticide in the transcriptome databases. This study showed that P450, CarE and GST together resulted in moderate resistance to butene‐fipronil in locusts. The analysis revealed several overexpressed detoxification enzyme genes that will be the focus of future studies on the mechanism of resistance to butene‐fipronil. 

This study examined diamondback moth (Plutella xylostella) strains showing high-level resistance to cyantraniliprole (KA17 strain) and to flubendiamide and chlorantraniliprole (KU13 strain). The LC50 value of the KA17 strain against cyantraniliprole was ca. 100-fold higher than that of the KU13 strain. The KA17 strain also exhibited high-level resistance to chlorantraniliprole and flubendiamide equivalent to those in the KU13 strain. The KU13 strain showed a higher LC50 value against cyantraniliprole than the susceptible strains. However, the LC50 value of the KU13 strain against cyantraniliprole was below the agriculturally recommended concentration. Subsequent QTL analysis using ddRAD-seq identified the resistance responsible regions of the KA17 and KU13 strains with different diamide resistance profiles. Ryanodine receptor (RyR) gene was included in the identified regions. Single nucleotide polymorphism calling in the RyR gene using RNA-seq found previously reported G4946E (amino acid mutation from glycine to glutamic acid at amino acid position 4946) and novel I4790K (amino acid mutation from isoleucine to lysine at amino acid position 4790) mutations, respectively, in the RyR of the KU13 and KA17 strains. Functional significance of I4790K in the resistance was confirmed in calcium imaging of the human embryonic kidney 293T cell line expressing Bombyx mori RyR with the mutation. This reporting is the first describing I4790K as a fundamental mechanism responsible for the resistance to the diamides including cyantraniliprole. From this study, we also report up-regulated expression of some degradation enzymes and that of the RyR gene in the KA17 and KU13 strains based on results of RNA-seq data analysis.

Halyomorpha halys (Stål), the brown marmorated stink bug, is a highly invasive insect species due in part to its exceptionally high levels of polyphagy. This species is also a nuisance due to overwintering in human-made structures. It has caused significant agricultural losses in recent years along the Atlantic seaboard of North America and in continental Europe. Genomic resources will assist with determining the molecular basis for this species’ feeding and habitat traits, defining potential targets for pest management strategies. Analysis of the 1.15-Gb draft genome assembly has identified a wide variety of genetic elements underpinning the biological characteristics of this formidable pest species, encompassing the roles of sensory functions, digestion, immunity, detoxification and development, all of which likely support H. halys’ capacity for invasiveness. Many of the genes identified herein have potential for biomolecular pesticide applications. Availability of the H. halys genome sequence will be useful for the development of environmentally friendly biomolecular pesticides to be applied in concert with more traditional, synthetic chemical-based controls.

Cabbage aphid, Brevicoryne brassicae (L.) (Hom.: Aphididae) is an important pest of crucifers and is controlled by different insecticides, especially dimethoate.The toxicity of dimethoate in six populations of the pest from different parts of Iran was assayed using Leaf-dip method. The bioassay results indicated significant difference in susceptibility to dimethoate among the six populations that were investigated. The highest level of resistance to dimethoate was obtained for Mehrshahr (Meh) population (RR= 91.25). Diethyl maleate (DEM), ,piperonylbutoxide (PBO), and triphenyl phosphate (TPP) suppressed the level of resistance to dimethoate, indicating the resistance to this insecticide was caused by glutathione S-transferases (GSTs), mixed function oxidases, and esterases, respectively. Cytochrome P450 monooxygenases and GSTs activity increased, respectively, 2.7 and 9.6-fold in resistant population compared with the susceptible one. When α-naphthyl acetate was used as substrate, up to 4-fold increase in esterase activity was observed in resistant population. Moreover, 6.2-fold elevation in esterase activity was shown in resistant strain when β-naphthyl acetate was the substrate. Overall, the mechanisms of insecticide resistance in cabbage aphid populations from six regions of Iran were related to GSTs, esterase, and cytochrome P450 monooxygenases activities.

A major challenge to sustainable agricultural pest control is the rapid evolution of insecticide resistance. This is caused by mechanisms that reduce insecticide efficacy. Understanding the genetic mechanisms of resistance is essential for DNA‐based monitoring of resistance in field populations. One such insecticide is indoxacarb, an important selective control option for Helicoverpa armigera in a range of crops including grain, horticulture and cotton. Recently, a strain of H. armigera (GY7‐39) resistant to indoxacarb (198‐fold) was isolated from field‐collected moth. To identify the indoxacarb resistance locus, GY7‐39 was backcrossed for six generations to susceptible strain New GR. In each generation, only resistant males were used to cross back to New GR. Genotype‐by‐sequencing was carried out on 95 H. armigera samples. In total, 13 203 tags with 8697 unique locations on the H. armigera genome were obtained. The indoxacarb resistance locus in strain GY7‐39 was mapped to a 2.6 Mbp region on chromosome 16. In this region, two closely linked loci (IndoR1 and IndoR2) were found to be associated with indoxacarb resistant GY7‐39. We mapped indoxacarb resistance in GY7‐39 to two closely linked loci IndoR1 and IndoR2 in a narrowed 2.6 Mbp region of H. armigera chromosome 16. The results provide essential background data for future genetic investigations including fine mapping of the indoxacarb resistance gene and the eventual development of an effective DNA‐based diagnostic to support resistance management.