RELATIONS ENTRE LA COCHENILLE BLANCHE Parlatoria blanchardiTargiono-Tozzetti (Homoptera-Diaspididae) ET QUELQUES VARIETES DE DATTES A OUARGLA

Abstract

The white cochineal of the date palm Parlatoria blanchardi TARG. is probably the biggest enemy of the date palm in Algeria. The results showed that: In the conditions of the region Ouargla, the cochineal white evolves according to different varieties of dates. Varieties are the most infested Hamraya, Deglet-Nour and Ghars with 19.68, 15.50 and 15.13 coch./cm2, followed by Degla-Beida, Bayd-Hmamand Tamsritinfested with respective degrees of infestation 9.71, 8.37 and 6.99 coch./cm2. This difference may be relation to variable carbohydrate composition of six varieties. Furthermore, the density of white cochineal varies according to factors such as variety, age and position of palm leaf crown. On the leaf crown, infestations are higher at the outer ring in all varieties of palm. In terms of age, young palms are most infested with respect to older palms. Temperature is an important factor that influences the duration and extent of generations. Cochineal prefers areas protected from direct sunlight to grow, actually directions North and East have higher rates of infestation highest. For a reasonable fight, the ideal method is to use the cleanest and most efficient especially biological control using insect predatorsin conjunction with other types of control.