A very first comprehensive study on hover fly (Diptera: Syrphidae) identification in Bangladesh, integrating molecular approach with taxonomic key analysis

This is the authors' abstract. We don't add key points for this paper.

Hoverflies serve vital roles in pollination and biological control. This is the first systematic study of hoverfly diversity in Bangladesh, using both morphological and COI -based DNA barcoding approaches for accurate species identification. A total of 953 hoverfly specimens were collected from agricultural habitats, revealing 20 species across 12 genera. Eristalinus Rondani was the most prevalent genus (43%), with peak activity during pre- and post-monsoon seasons. COI gene sequencing was performed to conduct molecular analyses of 34 morphologically distinct specimens. BLASTn comparison confirmed species identities through strong sequence similarity to reference sequences in GenBank, supporting morphological classification and indicating possible cryptic diversity. Multiple sequence alignment showed >93% genetic similarity, with a strong AT bias (>65%). The intraspecific divergence was minimal (0 - 0.005), while the interspecific divergence ranged up to 0.266, supporting robust species delimitation. Phylogenetic relationships inferred through Maximum Likelihood method confirmed taxonomic groupings. Haplotype network analysis identified Asarkina ericetorum (Fabricius) as exhibiting the highest number of mutational steps (26) among the observed haplotypes, and codon usage bias indicated a preference for UUA codons (RSCU = 4.53). These findings provide foundational data for Syrphid taxonomy in Bangladesh and highlight the utility of integrated approaches for documenting insect biodiversity in underexplored tropical regions.