Mineral nutrition as a lever for the control of Parlatoria ziziphi (Hemiptera: Coccomoprha: Diaspididae) in Algeria (Rouiba region)

This work focuses on the comparative study of Parlatoria ziziphi (Hemiptera: Coccomorpha: Diaspididae) on citrus trees and the influence of mineral nutrition on its variation. The results demonstrate that infestations of P. ziziphi on lemon trees are more significant than on clementine trees (10078/6842 individuals), especially on older leaves (6850/5250 individuals). The periods of strong infestations occur in January and March. The differences in potassium, sodium, calcium, magnesium, and iron levels are highly significant (p=0.001) and vary depending on the variety, leaf age, and time of year. Potassium plays a limiting role in the proliferation of P. ziziphi on clementine and lemon trees. It is notably higher on clementine trees, especially in young leaves (2.11% in May), where the infestation has declined. The same applies to sodium, with higher concentrations on clementine trees (1.28% in March) and lemon trees (1.02% in May). The highest levels correspond to a low proliferation of this scale insect, regardless of leaf age in both varieties. However, there is a synchronization between calcium levels and the abundance of P. ziziphi populations on both young and old leaves of both varieties. Magnesium, with higher concentrations (0.79%) in lemon trees and in older leaves (0.77%), is inversely correlated with the abundance of the scale insect. Copper and iron have no marked influence on the scale insect, but lemon trees have a higher copper content (0.40 ppm) compared to clementine trees (0.39 ppm), suggesting that these factors promote infestation.