DNA Barcoding Culicoides Biting Midges (Diptera: Ceratopogonidae) in Northeast Brazil

Biting midges of the genus Culicoides are small insects associated with the transmission of several pathogens, which requires the correct identification of the species, for implementation of effective strategies against these insects. However, many species are difficult to identify only by morphological characters. Therefore, the use of molecular methods can help in the taxonomy and systematics of this group. Here, the DNA barcode approach was evaluated for nine species of Culicoides from the State of Maranhao, Brazil. We generated 39 sequences from a 476 bp (base pairs) fragment of the cytochrome c oxidase subunit I (COI) mitochondrial gene. To assess the usefulness of COI barcodes for the identification of these species, paired genetic distances from intra and interspecific comparisons and phylogenetic trees were generated in MEGA and RAxML/BEAST softwares, respectively. In addition, species delimitation was performed using the PTP, GMYC, and ABGD algorithms. The intra and interspecific genetic distances showed a clear distinction between them, demonstrating that, for the taxa studied, there can hardly be ambiguous identifications with barcodes. In the same sense, the phylogenetic reconstruction resulted in well-supported clades for all morphospecies analyzed.

Automated summary

The study evaluated the effectiveness of DNA barcoding using COI gene for identifying nine species of Culicoides in the State of Maranhao, Brazil. The results showed that COI barcodes can accurately distinguish between species, making it an effective tool for species identification in this genus.