Mitogenome characteristics of two Tetragonula stingless bees (Hymenoptera: Apidae) from Hainan, China

The complete mitochondrial genomes (mitogenomes) of two ecologically important stingless bees, Tetragonula gressitti (Sakagami) and T. laeviceps (Smith), were sequenced and analyzed. Both species display the typical insect mitogenome structures but exhibit species-specific structural rearrangements and sequence variation. Their mitogenomes are AT-rich (81.5% and 75.2%, respectively), significantly influencing codon usage patterns. We identified novel features in tRNA and rRNA secondary structures, and observed gene rearrangements that exceed the typical conservatism in Hymenoptera, likely reflecting adaptation to distinct ecological pressures. Phylogenomic analyses robustly place both species within a monophyletic Meliponini clade, distinct from other Apoidea (Apis and Bombus), supporting their current taxonomic placement. These mitogenomes provide valuable resources for Meliponini phylogenetics and may inform conservation and utilization strategies for these species.