The effect of augmentative releases of indigenous parasitoid, Coccophagus scutellaris (Hymenoptera: Aphelinidae) on populations of Pulvinaria tenuivalvata (Hemiptera: Coccoidea) in Egypt

摘要

The sugarcane soft scale, Pulvinaria tenuivalvata (Homoptera: Coccidae) has recently become a pest and caused serious damage to sugarcane in Egypt. This paper examines the potential of biological control of P. tenuivalvata with an indigenous parasitoid, Coccophagus scutellaris (Hymenoptera: Aphelinidae). In a field experiment conducted in the Qena and Aswan governorates in Egypt, in 2003, a total of 350 000 adult parasitoid individuals were released monthly in cane fields at 16 sites. The findings indicated that the releases more or less doubled the parasitism on P. tenuivalvata. This ranged from 11-24% in the controls compared to 28-56% in the treated blocks in Qena governorate. The respective figures in the Aswan governorate were 9-14% and 25-47%. It was concluded that the indigenous parasitoid, C. scutellaris, is a promising biological control agent for controlling P. tenuivalvata in Egypt.