Evaluation of Aphytis melinus De Bach (Hymenoptera: Chalcidoidea: Aphelinidae) in Citrus Orchards as a Biocontrol Agent of Black Scale, Parlatoria ziziphi (Lucas) (Hemiptera: Coccoidea: Diaspididae) in Egypt

Abstract

The black parlatoria scale, Parlatoria ziziphi (Lucas) (Coccoidea: Diaspididae), is one of the most important pests attacking citrus trees in different parts of the world including Egypt. This work deals with rearing, release and evaluation of the parasitoid, Aphytis melinus De Bach (Hymenoptera: Aphelinidae) to control P. ziziphi biologically. In all, 250000 adult parasitoid individuals were released monthly on citrus at five locations in Cairo, Giza and Qalyubiya governorates during 2006 and 2007. At Heliopolis (Cairo), where A. melinus was present prior to the augmentative release, the per cent parasitism in the control block was 15 and 75% while it was 73 and 87% in the treatment block during the two years under consideration. At Dokki (Giza) also, A. melinus was present prior to the augmentative releases and the peak of parasitism reached 18 and 82% in the control block, compared to 86 and 91% in the treatment block. At El-Qanater El-Khriya and Tukh in Qalyubiya, A. melinus was present prior to the augmentative releases. In El-Qanater El-Khriya, the peak of parasitism reached 41 and 67% in the treatment block, compared to 8 and 46% in the control block. In Tukh, the peak of parasitism reached 31 and 65% in the treatment block, compared to 4 and 35% in the check block. At Qalub, where the parasitoid was not present prior to the augmentative releases, the peak of parasitism reached 22 and 36% in the treatment block, compared to 0 and 22% in the control block during the two years, respectively.