Molecular Species Delimitation Using COI Barcodes of Mealybugs (Hemiptera: Pseudococcidae) from Coffee Plants in Espírito Santo, Brazil

Abstract

Mealybugs are insects belonging to the family Pseudococcidae. This family includes many plant-pest species with similar morphologies, which may lead to errors in mealybug identification and delimitation. In the present study, we employed molecular-species-delimitation approaches based on distance (ASAP) and coalescence (GMYC and mPTP) methods to identify mealybugs collected from coffee and other plant hosts in the states of Espírito Santo, Bahia, Minas Gerais, and Pernambuco, Brazil. We obtained 171 new COI sequences, and 565 from the BOLD Systems database, representing 26 candidate species of Pseudococcidae. The MOTUs estimated were not congruent across different methods (ASAP-25; GMYC-30; mPTP-22). Misidentifications were revealed in the sequences from the BOLD Systems database involving Phenacoccus solani × Ph. solenopsis, Ph. tucumanus × Ph. baccharidis, and Planacoccus citri × Pl. minor species. Ten mealybug species were collected from coffee plants in Espírito Santo. Due to the incorrect labeling of the species sequences, the COI barcode library of the dataset from the database needs to be carefully analyzed to avoid the misidentification of species. The systematics and taxonomy of mealybugs may be improved by integrative taxonomy which may facilitate the integrated pest management of these pests.

Improving DNA barcoding library of armored scale insects (Hemiptera: Diaspididae) in China

“…DNA barcoding has been used with many taxa in the Coccoidea for primer designing [25], species identification [26][27][28][29][30][31], genetic diversity estimation [32], and quarantine inspection [33]. However, a search in the Barcode of Life Data System (BOLD) database in July 2023 using the term "Diaspididae" produced 2412 published records, whereas the term "Diaspididae China" produced only 8 records (~0.3%), suggesting a lack of data on the biodiversity of armored scale insects in China.…”

DNA Barcodes for Evolution and Biodiversity

“…A finding that is particularly interesting and relevant for many taxa, especially within Collembola and Oligochaeta, which are considered major players in (soil) ecosystems, is that many samples cannot be assigned to particular species, which indicates that there is a lack of reference data in the two largest databases (BOLD and GenBank). The third paper [19] establishes a DNA barcode library for mealybug species from Santo, a major coffeeproducing region in Brazil, by combining newly generated DNA barcodes with barcodes available on BOLD. The study shows that, in principle, molecular species delimitation works well in the relevant taxa, if obviously misidentified samples on BOLD are taken into account/excluded.…”