Taux d’infestation par la cochenille blanche (Parlatoria blanchardi Targ.) sur quelques variétés des dattes dans la région de Metlili (Ghardaïa)

Abstract

The white cochineal of date palm or in its term Parlatoria blanchardi TARG it’s the biggest enemy of date palm lands in Algeria. Our work presents a contribution to the evaluation of infestation rate by the white cochineal on three varieties of the date in three palm groves of Metlili (Guemgouma, Souareg and Chabet Sid sheik). The gotten results are: .The density of white cochineals varies according to several factors, we mention, the variety, orientation of the palm and according to the floor leaf. The variety of Ghars is the more infested by report the other varieties with a strength 62.52cochenille/cm² to the level the palm grove of Chabet Sid sheik and orientation is and the more infested that the other. Concerning the floor leaf, the infestations are raised more to the level of the lower floor with densities of 43,29 cochenille/cm² to the level the palm grove of Chabet Sid sheik .For the evaluation of degree of white cochineal infestation has been estimated by 0.5-1 for the majority of the varieties that corresponds to a debit of infestation. Only, a population (notation 2) the month of March in the Chabet palm grove Sid sheik. In definitive, he/it is to signal that this evolution is influenced by climatic factors (wind, humidity…) and physical orientation, altitude…)