Application of character based DNA barcode: a novel approach towards identification of fruit fly (Diptera: Tephritidae) species from cucurbit crops

Background: The Tephritidae family, commonly referred to as true fruit flies, comprises of a substantial group within order Diptera. Numerous species within this family are major agricultural pests, with a tendency to infest a wide array of fruits and vegetables in tropical and sub- tropical regions, leading to considerable damage and consequent reductions in the market value of the crops.

Methods and results: The current study was aimed to propose a promising solution to the menace posed by fruit flies by offering rapid, accurate and reliable species identification by using character-based DNA barcode methodology. The Tephritid specimens were collected from Cucurbitaceous plants of southern parts of West Bengal, India, and a total of eight species from Tephritidae family were obtained belonging to three genera, namely Bactrocera (Macquart, 1835), Dacus (Fabricius, 1805) and Zeugodacus (Hendel, 1927). Their morphological features were meticulously studied based on available literature, along with genetic analysis based on mitochondrial COI and ND1 gene sequences. A total of 30 uniquely variable sites at nucleotide position 42,48,51,60,66,72, 105,111,144,198,207,243, 273,297,307,318,345,357, 375,378,381,387,399,400, 402,436,444,450,453 and 460 in COI gene were discerned among Tephritid species in the present study.

Conclusions: The character-based DNA barcode holds the potential to differentiate closely related species of fruit flies and morphologically look-a-like ones. The novel method will be very significant in terms of rapid, precise and reliable species identification and might be extremely essential for early detection during pest outbreaks by facilitating timely intervention strategies to mitigate crop damage.