Important predaceous insects of citrus aphids (Hemiptera: Aphididae) in the north of Iran

Several species of aphids cause severe damage to citrus in the north of Iran. Predatory insects play an important role in biological control of the pests in citrus orchards. In this study, potential predatory insects of citrus aphids, Aphis spiraecola, A. gossypii and Toxoptera aurantii, were identified and their seasonal population dynamics on Citrus unshiu and C. sinensis were investigated during 2016-2017. Overall, four species were identified as dominant predatory insects of citrus aphids in Mazandaran province including Xanthogramma pedissequum (Syrphidae), Scymnus subvillosus, Coccinella septempunctata (Coccinellidae), and Aphidoletes aphidomyza (Cecidomyiidae). Among these species, X. pedissequum and S. subvillossus were more abundant predators in the C. sinensis and C. unshiu orchards compared to the two other species. The predatory insects were observed when means of environmental temperature was about 15-20ºC. Population fluctuations, population densities and presence periods of the predatory insects were different on the two host plants. Results of this study can be used in integrated pest management programs of citrus aphids in citrus orchards in the north of Iran.