The codling moth Cydia pomonella, a major invasive pest of pome fruit, has spread around the globe in the last half century. We generated a chromosome-level scaffold assembly including the Z chromosome and a portion of the W chromosome. This assembly reveals the duplication of an olfactory receptor gene (OR3), which we demonstrate enhances the ability of C. pomonella to exploit kairomones and pheromones in locating both host plants and mates. Genome-wide association studies contrasting insecticide-resistant and susceptible strains identify hundreds of single nucleotide polymorphisms (SNPs) potentially associated with insecticide resistance, including three SNPs found in the promoter of CYP6B2. RNAi knockdown of CYP6B2 increases C. pomonella sensitivity to two insecticides, deltamethrin and azinphos methyl. The high-quality genome assembly of C. pomonella informs the genetic basis of its invasiveness, suggesting the codling moth has distinctive capabilities and adaptive potential that may explain its worldwide expansion.

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Bread wheat (Triticum aestivum L.) is a major staple crop in the world. Grain weight is a major factor of grain yield in wheat, and the identification of candidate genes associated with grain weight is very important for high-yield breeding of wheat. TaGW2 is an orthologous gene of rice OsGW2 that negatively regulates the grain width and weight in rice. There are three TaGW2 homoeologs in bread wheat, TaGW2A, TaGW2B, and TaGW2D. In this study, a specific TaGW2-RNA interference (RNAi) cassette was constructed and transformed into a Chinese bread wheat variety 'Shi 4185' with small grain. The transcript levels of TaGW2A, TaGW2B, and TaGW2D were simultaneously downregulated in TaGW2-RNAi transgenic wheat lines. Compared with the controls, TaGW2-underexpressing transgenic lines displayed significantly increases in the grain width and weight, suggesting that TaGW2 negatively regulated the grain width and weight in bread wheat. Further transcript analysis showed that in different bread wheat accessions, the transcript abundance of TaGW2A was negatively associated with the grain width.