Use of ITS-1 to Identify Bactrocera dorsalis and Bactrocera occipitalis (Diptera: Tephritidae): A Case Study Using Flies Trapped in California from 2008 to 2018

Abstract

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Genetical, Morphological, Behavioral, and Ecological Traits Support the Existence of Three Brazilian Species of the Anastrepha fraterculus Complex of Cryptic Species

“…The present ITS-1 analysis of samples of the Brazilian species showed that, although the nucleotide variability was low, the sequences from the three species showed structural differences, including SNPs, indels, and other fixed differences, as previously described (Prezotto et al, 2019). ITS-1 sequences have been an important marker to identify species within complexes in several types of organisms, and were also adopted as the molecular marker to distinguish two species of the Bactrocera dorsalis complex by the International Plant Protection Convention (Barr et al, 2021).…”

Genomic data reveal new species and the limits of mtDNA barcode diagnostics to contain a global pest species complex (Diptera: Tephritidae: Dacinae)

“…Considering the phylogenetic distance inferred from nuclear DNA between B. dorsalis and B. carambolae , a distinct COI cluster for B. carambolae likely exists but remains unsampled, or has existed in the past, but is ultimately not useful for species diagnosis. A diagnostic insertion in the internal transcribed spacer 1 region (ITS‐1) has also been recorded between B. dorsalis and B. carambolae , further suggesting evolutionary divergence and arguing against incomplete lineage sorting (Barr et al, 2021). For B. incognita and B. raiensis , the situation is less clear, and there may be incomplete lineage sorting with B. dorsalis , as they are also very closely related based on the RAD‐seq data.…”

“…There may be population‐specific (i.e., geographic areas), where some of these species can be distinguished morphologically, but considering the extent of confusion highlighted by our molecular data, this will need to be re‐evaluated per region. In addition to the molecular identification methods described here, ITS‐1 has also been shown to be a reliable marker to separate B. dorsalis s.s ., B. carambolae and B. occipitalis (Barr et al, 2021).…”

“…In the Philippines, B. occipitalis appears more variable than on Borneo and often have a costal band that does not overlap vein R 2+3 —specimens without the costal band overlapping vein R 2+3 are impossible to reliably distinguish from sympatric B. dorsalis based on morphology alone. In addition to the molecular methods presented here, ITS‐1 sequence data can be used to separate B. dorsalis and B. occipitalis (Barr et al, 2021).…”

Inadequate molecular identification protocols for invasive pests threaten biosecurity

“…Firstly, DNA barcoding is not limited to species identification but is also commonly used in the study of species delimitation (DeSalle et al, 2005). Secondly, in its strictest sense, the term DNA barcoding only applies to the use of a fragment of the COI gene, but other markers have been proposed and used for species identification (e.g., Barr et al, 2021; Lee et al, 2019; van Nieukerken et al, 2012). Nonetheless, with 4.6 M sequences for 241 k species in the publicly available Barcoding of Life Datasystems (BOLD) (Ratnasingham & Hebert, 2007) as of August 2022, COI currently represents a high potential resource as the largest public database available for any one marker that can be used for species identification.…”