Predation potential of flower fly Eupeodes nuba (Wiedemann, 1830) (Diptera: Syrphidae) on black bean aphid Aphis fabae Scopoli (Hemiptera: Aphididae) and the parasitoids species on its host in the field

The flower fly species, Eupeodes nuba (Wiedemann, 1830) (Diptera: Syrphidae) is crucial for agroecosystems as it provides various ecosystem services such as pest control through the use of predatory larvae and crop pollination by adults. In this research, the consumption rate of different instars of Aphis fabae (Scopoli, 1763) by E. nuba larvae has been studied under laboratory conditions at 25±2 °C, 60±10% humidity (RH). Fifty aphids and one larva of flower fly were present in each replicate. The results showed that the maximum number of A. fabae consumed by the larvae of E. nuba was 49.13 individuals at the third instar, followed by 35.73 individuals of aphids at the second instar and 16.26 individuals for the first instar of the predator. The highest daily consumption of aphids occurred during the third instar of the predator. A. fabae was heavily parasitized by different aphid parasitoids, Binodoxys acalephae (Marshall, 1896), Lysiphlebus fabarum (Marshall, 1896), and Aphelinus asychis (Walker, 1839) on the broad bean. Parasitization rates of these parasitoids increased during the broad bean plant season. The first recording of A. fabae as a new host for A. psychic. The survey of three parasitoids indicated that L. fabarum had the highest population in December, the parasitoid B. acalephae was the highest in January, and the highest population of A. asychis was recorded in February. It seems that biological control can be used as an alternative to chemical pesticides to control A. fabae.