Identifying Anastrepha (Diptera; Tephritidae) Species Using DNA Barcodes

Abstract

Molecular identification of fruit flies in the genus Anastrepha (Diptera; Tephritidae) is important to support plant pest exclusion, suppression, and outbreak eradication. Morphological methods of identification of this economically important genus are often not sufficient to identify species when detected as immature life stages. DNA barcoding a segment of the mitochondrial cytochrome oxidase I gene has been proposed as a method to identify pests in the genus. The identification process for these fruit flies, however, has not been explained in prior DNA barcode studies. DNA barcode methods assume that available DNA sequence records are biologically meaningful. These records, however, can be limited to the most common species or lack population-level measurements of diversity for pests. In such cases, the available data used as a reference are insufficient for completing an accurate identification. Using 539 DNA sequence records from 74 species of Anastrepha, we demonstrate that our barcoding data can distinguish four plant pests: Anastrepha grandis (Macquart) (Diptera; Tephritidae), Anastrepha ludens (Loew), Anastrepha serpentina (Wiedemann), and Anastrepha striata Schiner. This is based on genetic distances of barcode records for the pests and expert evaluation of species and population representation in the data set. DNA barcoding of the cytochrome oxidase I gene alone cannot reliably diagnose the pests Anastrepha fraterculus (Wiedemann), Anastrepha obliqua (Macquart), and Anastrepha suspensa (Loew).

Keywords: Tephritidae; biosecurity; identification; molecular.