Distribution, relative abundance, and level of infestation of the invasive peach fruit fly Bactrocera zonata (Saunders) (Diptera: Tephritidae) and its associated natural enemies in Sudan

Bactrocera zonata is a devastating invasive pest of tropical and subtropical horticultural crops. Since its detection in Sudan in 2011, almost no information has emerged regarding its bio-ecology. This study aimed to determine the pest’s range and potential distribution in Sudan, it’s relative abundance, infestation level, associated indigenous natural enemies and assess their role in its natural control. The infestation levels of B. zonata and B. dorsalis were assessed in fruit orchards between 2014 and 2016. MaxEnt software was used to predict the distribution of both species countrywide using occurrence points. Out of eighteen states, B. zonata was recorded coexisting with B. dorsalis in nine states, with relative abundance ranging between 0.2–100%. This co-occurrence was also confirmed by MaxEnt that showed high climate suitability in these states, with the mean annual temperature being the most important variable affecting the distribution of both species. Fruits infested with B. zonata included mango, guava, grapefruit, oranges and papaya. Three parasitioids; Tetrastichus giffardianus, Agonaspis sp. and Psytallia sp. were found associated with B. zonata. Our results provide evidence that the pest is widely spread across the country and poses a significant threat of invasion into neighboring countries and beyond unless early detection and eradication programs are applied.