Assessing Panonychus ulmi (Acari: Tetranychidae) Infestations and Their Key Predators on Malus domestica Borkh in Varied Ecological Settings

Abstract

This study investigates the infestation dynamics of Panonychus ulmi McGregor 1916 and its associated predators in Malus domestica borkh orchards across three towns in Morocco: Midelt, Ait Sebaa, and Imouzzer-Kender, situated in the Fez-Meknes and Draa-Tafilalt regions. Ait Sebaa (Fez-Meknes region), characterized by high temperatures and a lower altitude, exhibited a substantial increase in P. ulmi and its predators. In contrast, Midelt (Draa-Tafilalt region), with the highest altitude, demonstrated lower mite counts. Imouzzer-Kender (Fez-Meknes region), at an intermediate altitude, showed moderate mite levels. Detailed findings reveal a positive correlation between P. ulmi and temperature, as well as with phytoseiid mites. Conversely, a negative correlation exists between P. ulmi and altitude. Additionally, a positive correlation between phytoseiid mites and temperature is identified. Overall, this study provides valuable information on the ecological interactions between mites, temperature, altitude and humidity in distinct Moroccan regions, highlighting the need to take regional specificities into account in pest management strategies.