COI barcoding of plant bugs (Insecta: Hemiptera: Miridae)

Area of Science:

• Entomology
• Molecular Biology
• Taxonomy

Background:

• The family Miridae (plant bugs) is a highly diverse and economically significant insect group within Heteroptera.
• Morphological identification of mirid species is challenging and labor-intensive, hindering efficient research and pest management.

Purpose of the Study:

• To assess the efficacy of cytochrome c oxidase subunit I (COI) DNA barcoding for identifying 123 species of plant bugs across seven subfamilies.
• To evaluate COI barcoding as a potential tool for taxonomic revision and species identification within the Miridae family.

Main Methods:

• DNA extraction and sequencing of the COI gene from 123 Miridae species.
• Analysis of genetic distances to determine interspecific and intraspecific variation.
• Phylogenetic analysis to visualize species clustering and relationships.

Main Results:

• COI barcoding successfully distinguished 120 out of 123 investigated Miridae species, revealing unique COI sequences for most.
• A significant barcoding gap was observed, with average minimum interspecific genetic distance ~37 times greater than average maximum intraspecific genetic distance.
• Three *Apolygus* species (*A. lucorum*, *A. spinolae*, *A. watajii*) clustered together despite distinct morphology, suggesting potential taxonomic issues.

Conclusions:

• COI barcoding is a powerful and efficient tool for the identification of plant bug species, complementing traditional methods.
• The findings support the utility of COI barcoding for taxonomic revisions, particularly for species complexes like the *Apolygus* group.
• DNA barcoding offers an economically viable approach for various scientific research fields involving Miridae identification.