# Whole-genome assembly and annotation of the acorn weevil, Curculio nanulus (Coleoptera: Curculionidae)

## TL;DR

Researchers assembled and annotated the genome of the acorn weevil, providing a valuable resource for studying its evolution and ecological interactions.

## Contribution

The study provides the first whole-genome assembly for Curculio species, enabling comparative genomic analyses.

## Key findings

- A high-quality genome assembly of C. nanulus was generated with a contig N50 of 7.7 Mbp and 98.97% gene completeness.
- The genome reveals a significant expansion of repetitive elements in Curculio and related species.
- The study also assembled the genome of C. caryae, enabling comparative analysis with other weevil genomes.

## Abstract

The acorn weevil Curculio nanulus (Coleoptera: Curculionidae) is a seed predator that lays its eggs inside developing acorns and hickory nuts in the western United States. The female weevil uses her elongated rostrum to excavate a hole into the seed, creating a protected site for oviposition. Natural history traits among Curculio species—such as host specificity and variation in larval diapause—suggest a dynamic evolutionary relationship with their host plants. These traits are best studied through a comparative genomic framework, but such analyses cannot currently be undertaken due to the lack of whole-genome assemblies for Curculio species. To address this gap, we generated a whole-genome assembly for C. nanulus using PacBio HiFi sequencing. The resulting assembly is ∼1.5 Gbp in length, with high contiguity (contig N50 = 7.7 Mbp) and gene completeness (BUSCO score: 98.97%). To enable comparative analysis, we also assembled the genome of the pecan weevil, Curculio caryae, using publicly available PacBio HiFi reads. For both species, we annotated repetitive elements and protein-coding genes and compared these features with those of other weevil genomes. Our results reveal a marked expansion of repetitive elements within Curculio and its close relatives. These genomic resources provide a foundation for investigating seed predation, co-speciation, and host-parasite evolutionary dynamics in Curculio and related taxa, as well as their impacts on forest ecology.