How does agricultural intensification impact insect diversity and abundance in the palm groves of Algeria's Sahara?

This study investigated the impact of agricultural intensification (AI) on insect diversity and abundance in date palm orchards (<i>Phoenix dactylifera</i> L.) in north-eastern Algeria under a Saharan climate. Insect sampling was conducted using various traps from September 2020 to August 2021 in three orchards along a gradient of agricultural intensification (low, medium and high). The study involved the examination of 5,633 insect specimens representing 267 species spanning 11 orders, 93 families and 195 genera. The results indicate that the diversity and abundance of insects are highest in moderately managed palm groves, followed by highly intensified groves and are lowest in non-intensified groves. The species composition is significantly more similar between moderately and highly intensified palm groves. The degree of agricultural intensification has a diferential affect on various insect groups, favouring the diversity or abundance of some, while limiting that of others. This is the case of Diptera and Hymenoptera, which are sensitive to agricultural intensification. Globally, moderate intensification has a more positive impact on the diversity and abundance of various insect orders. This highlights the need for the rational and controlled use of chemical inputs in order to preserve the diversity of insects in palm groves where they provide vital ecosystem services.