DNA barcode polymorphism within a common widespread rove beetle Quedius molochinus (Coleoptera: Staphylinidae)

Area of Science:

• Entomology
• Molecular Systematics
• Biodiversity Research

Background:

• Q. molochinus, a recently revised species, was assessed using phylogenetic methods.
• External morphology and aedeagal shape initially identified specimens.
• Previous understanding suggested a well-defined species status for Q. molochinus.

Purpose of the Study:

• To investigate the phylogenetic relationships within Q. molochinus.
• To determine if molecular data supports distinct species status for identified clades.
• To explore the utility of endophallic morphology in differentiating cryptic species.

Main Methods:

• DNA barcoding using cytochrome c oxidase subunit I (COI) gene.
• Phylogenetic assessment of 22 Q. molochinus specimens.
• Preliminary examination of male aedeagal internal sac (endophallus) morphology.

Main Results:

• Three non-sister clades were identified within Q. molochinus based on COI barcodes.
• Significant molecular divergence (6.3-7.8%) was observed among these clades.
• No notable morphological variants were found in the endophallus among the clades.

Conclusions:

• Molecular data suggests potential cryptic speciation within Q. molochinus.
• Endophallic morphology did not align with molecularly defined clades, contrasting with other beetle studies.
• Further investigation with nuclear DNA markers and detailed endophallic examination is recommended.