<p><strong>Population dynamics and trophic interactions between <em>Oligonychus afrasiaticus</em> (Acari: Tetranychidae) and its predator <em>Stethorus punctillum</em> (Coleoptera: Coccinellidae) on date palms in the north</strong><strong>-</strong><

Drought is causing Algerian palm groves to suffer an increase in date palm acariasis, which is caused by the mite Oligonychus afrasiaticus (McGregor, 1939). This mite feeds on the fruit's epidermal cell, giving it a rough appearance and making it unfit for consumption. The study was carried out in the Souf region, north of the Grand Erg Oriental in Algeria over 12 months from July 2020 to June 2021. Our study aimed to determine the infestation of the date dust mite O. afrasiaticus, and to understand the population dynamics of this mite and its predator Stethorus punctillum (Weise, 1891) in the Deglet Nour and Ghars varieties, within different types of palm groves (El Bayadha 33° 19' 40'' N, 6° 55' 33'' E, Oued Alanda 33° 17' 25'' N, 6° 46' 39'' E and Sandarous 33° 13' 18'' N, 6° 58' 40'' E). Two sampling methods were used, direct collection of dates using the date branch sampling method and the date palm branch striking method. The result showed that the beginning of O. afrasiaticus infestation of dates coincided with the green phenological stage of dates (Kimri) and ended with the beginning of the Bser stage (Khalal). Our results showed that the Ghout palm grove was the least affected by this pest compared with the other groves. Dates of the Deglet Nour variety have the highest infestation rates compared with the Ghars variety. We also observed that the ladybird, S. punctillum, acts as a key predator of the date palm spider mite highlighting a significant trophic interaction between the two species. Our results showed that the population dynamics of these acarophagous insects vary according to the degree of presence of their trophic preferences and the ecological factors of the biotope.