Chromosome genome assembly and whole genome sequencing of 110 individuals of Conogethes punctiferalis (Guenée).

The yellow peach moth, Conogethes punctiferalis, is a highly polyphagous pest widespread in eastern and southern Asia. It demonstrates a unique ability to adapt to rotten host fruits and displays resistance to pathogenic microorganisms, including fungi. However, the lack of available genomic resources presents a challenge in comprehensively understanding the evolution of its innate immune genes. Here, we report a high-quality chromosome-level reference genome for C. punctiferalis utilizing PacBio HiFi sequencing and Hi-C technology. The genome assembly was 494 Mb in length with a contig N50 of 3.25 Mb. We successfully anchored 1,226 contigs to 31 pseudochromosomes. Our BUSCO analysis further demonstrated a gene coverage completeness of 96.3% in the genome assembly. Approximately 43% repeat sequences and 21,663 protein-coding genes were identified. In addition, we resequenced 110 C. punctiferalis individuals from east China, achieving an average coverage of 18.4 × and identifying 5.8 million high-quality SNPs. This work provides a crucial resource for understanding the evolutionary mechanism of C. punctiferalis' innate immune system and will help in developing new antibacterial drugs.

Genome of the hoverfly Eupeodes corollae provides insights into the evolution of predation and pollination in insects.

BACKGROUND: Hoverflies (Diptera: Syrphidae) including Eupeodes corollae are important insects worldwide that provide dual ecosystem services including pest control and pollination. The larvae are dominant predators of aphids and can be used as biological control agents, and the adults are efficient pollinators. The different feeding habits of larvae and adults make hoverflies a valuable genetic resource for understanding the mechanisms underlying the evolution and adaptation to predation and pollination in insects. RESULTS: Here, we present a 595-Mb high-quality reference genome of the hoverfly E. corollae, which is typical of an aphid predator and a pollinator. Comparative genomic analyses of E. corollae and Coccinellidae (ladybugs, aphid predators) shed light on takeout genes (3), which are involved in circadian rhythms and feeding behavior and might regulate the feeding behavior of E. corollae in a circadian manner. Genes for sugar symporter (12) and lipid transport (7) related to energy production in E. corollae had homologs in pollinator honeybees and were absent in predatory ladybugs. A number of classical cytochrome P450 detoxification genes, mainly CYP6 subfamily members, were greatly expanded in E. corollae. Notably, comparative genomic analyses of E. corollae and other aphidophagous hoverflies highlighted three homologous trypsins (Ecor12299, Ecor12301, Ecor2966). Transcriptome analysis showed that nine trypsins, including Ecor12299, Ecor12301, and Ecor2966, are strongly expressed at the larval stage, and 10 opsin genes, which are involved in visual perception, are significantly upregulated at the adult stage of E. corollae. CONCLUSIONS: The high-quality genome assembly provided new insights into the genetic basis of predation and pollination by E. corollae and is a valuable resource for advancing studies on genetic adaptations and evolution of hoverflies and other natural enemies.

Genomic features of the polyphagous cotton leafworm Spodoptera littoralis.

BACKGROUND: The cotton leafworm, Spodoptera littoralis, is a highly polyphagous pest of many cultivated plants and crops in Africa and Europe. The genome of this pest will help us to further understand the molecular mechanisms of polyphagy. RESULTS: Herein, the high-quality genome of S. littoralis was obtained by Pacific Bioscience (PacBio) sequencing. The assembled genome size of S. littoralis is 436.55 Mb with a scaffold N50 of 6.09 Mb, consisting of 17,207 annotated protein-coding genes. Phylogenetic analysis shows that S. littoralis and its sibling species S. litura diverged about 5.44 million years ago. Expanded gene families were mainly involved in metabolic detoxification and tolerance to toxic xenobiotics based on GO (Gene Ontology) and KEGG (Kyoto Encyclopedia of Genes and Genomes) pathway analysis. Comparative genomics analysis showed that gene families involved in detoxification and chemosensation were significantly expanded in S. littoralis, representing genetic characteristics related to polyphagy and an extensive host range. CONCLUSIONS: We assembled and annotated the reference genome of S. littoralis, and revealed that this pest has the genetic features of strong detoxification capacity, consistent with it being a significant risk to a wide range of host crops. These data resources will provide support for risk assessment and early warning monitoring of major polyphagous agricultural pests.