A total of 21 natural regulators of aphids on apple (predators and parasitoids) were found in Plovdiv`s area in 2006 - 2008. The predators are more abundant. The ladybirds have greater importance at the beginning of the vegetation period, particularly Coccinella septempunctata and Adalia bipunctata. Later in the season the population density of hover flies and the predatory midge Aphidoletes aphidimyza increase. Four parasitoids were found on D. plantaginea, two on D. devecta and only one on A. spiraecola and E. lanigerum. The aphidophgous species are not capable to control the population density of aphids on apple under economic injury level during the period of their mass development.
Natural regulators of aphids on apple in Plovdiv`s area