# Mitogenomic Characterization of Mining Bee Family Andrenidae (Hymenoptera: Apoidea: Anthophila) and Insights into Bee Phylogeny

## TL;DR

This study sequenced five mitochondrial genomes of Andrenidae bees from Tibet to better understand their evolution and phylogenetic relationships with other bee families.

## Contribution

The study provides the first mitogenomic data for Andrenidae and clarifies the phylogenetic position of this family within bees.

## Key findings

- The five Andrenidae mitogenomes ranged from 15,631 to 18,506 bp with high AT content (74.46–79.85%).
- Gene rearrangements and codon usage patterns were identified, with ATP8 showing the highest Ka/Ks ratio.
- Phylogenetic analyses placed Andrenidae as the sister clade to Halictidae + Colletidae, with Melittidae as the basal lineage.

## Abstract

Bees exhibit exceptional efficiency in pollination processes. The family Andrenidae, comprising over 3000 described species, represents an important lineage of bees, yet limited molecular information has constrained insights into its evolutionary history. This study sequenced and assembled five mitochondrial genomes of Andrenidae collected from Xizang, Tibet. Comparative genomic approaches were used to analyze nucleotide composition, codon preferences, and Ka/Ks ratios of the newly obtained mitogenomes. Furthermore, previously published datasets have been integrated to reconstruct phylogenetic relationships among bees employing both Bayesian Inference and Maximum Likelihood methods. These findings significantly expand the available molecular resources for Andrenidae and offer valuable references for future investigations into the evolutionary biology of this family and bees more broadly.

Andrenidae is a major pollinator lineage with considerable ecological importance, yet limited molecular resources have impeded comprehensive understanding of its evolutionary history. This study sequenced and assembled five mitogenomes of Andrenidae, which were collected from Xizang, Tibet. Analyses included sequence size, nucleotide composition, Ka/Ks ratios, and gene rearrangements. The assembled mitogenomes ranged from 15,631 to 18,506 bp in length. AT content (%) varied between 74.46 and 79.85. Relative synonymous codon usage analysis revealed that AUU, UUA, UUU, and UUA were the most frequently preferred codons. All 13 protein-coding genes displayed Ka/Ks values below one, with ATP8 showing the highest ratio and COX1 the lowest. Gene rearrangements occurred in all mitogenomes, and three distinct tRNA rearrangement patterns were detected. This study provided more available molecular data for future evolutionary biology studies of Andrenidae. Additionally, 24 previously published Apoidea mitogenomes (three outgroups and 26 ingroups) were incorporated to infer phylogenetic relationships using Maximum Likelihood and Bayesian Inference methods. The results supported Melittidae as the basal lineage of bees, while Andrenidae was recovered as the sister clade to Halictidae + Colletidae.