Role of hymenopterous parasits Aphelinidae in the regulation of levels of Lepidosaphes beckii (Newton, 1869) (Homoptera Diaspididae) populations on orange trees in Rouiba area (Algeria)

摘要

This present study put in evidence the dynamics of the populations of Lepidosaphes beckii(Newton, 1869) (Homoptera Diaspididae), and the study of the impact of its hymenopterousparasites Aphytis lepidosaphes Compere, 1955, Aphytis chrysomphali Mercet, 1912, Aphytisproclia Walker, 1839 and Aspidiotiphagus citrinus (Craw, 1831) on orange tree in the area ofRouiba. This diaspine develops three generations: one in autumn-winter, one in spring and onein summer. This scale insect presents a very marked affinity in the middle of the tree and theinferior faces of the leaves where the suitable conditions for its development seems to beoffered. The natural mortality of L. beckii is of two types: climatic for young stages andphysiological for the adult females. The parasitic incidence is almost the same for the youngstages and the adult with respectively 22.24% and 23.89%. The global rate of parasitism is23.24% insufficient to control its host.