Mandarin Yield Loss and Pupal Density Assessment of Chinese Fruit Fly at Citrus Pockets of Gandaki Province, Nepal

To ascertain the mandarin yield damage and pupal-density based future damage potential due to recent invasion of Chinese fruit fly (CFF) Bactrocera minax (Enderlein), a semi-structured questioning with commercial citrus growers of Gandaki Province and a field level assessment of the pupal density were carried out. Results revealed that the mandarin growers were facing sever CFF-infestation since 3-4 years, the fruits drop starting in July-August and reaching peak in September of the season leading into an average yield loss of 16.63±1.68% in Gandaki Province. Though 64% of the respondents were adopting collection and disposing of the fallen infested mandarin fruits leading into a significant decrease (78.95 ± 5.69% and 72.48 ± 3.17%, respectively in 2021 and 2022) in CFF pupal population, there were plenty of larvae gone for pupation which could be sufficient to infest the next-season mandarin. Therefore, an area-wide control measure focusing on orchard sanitation is imperative.