THESIS & RESEARCHES
Influence of different citrus cropping systems on insect diversity, and preliminary survey of Citrus tristeza virus and its aphid vectors in Mina and Chlef valleys (North-West Algeria)
Year:
2021
Author:
Benelhad-Djelloul Mouna
Over the last few decades, the Algerian citrus industry has received considerable public subsidies for the renewal of old plantations. As a result, some growers have turned to a new intensive production system instead of conventional extensive cropping. The management systems adopted have a significant impact on insect diversity and abundance and they therefore affect ecological stability and biodiversity. In this context, a comparative study was conducted on two citrus orchards in the Mina and Chlef Valleys to assess insect diversity and abundance in those areas. Analysis of recorded data revealed that extensive cropping systems preserve a greater insect diversity and allow different functional groups of insects such as predators and parasitoids to live and interact, (e.g., Coccinella septempunctata, Harmonia axyridis) in contrast to intensive systems. 717 insects belonging to 62 species were identified in the extensive orchard with a Shannon diversity index of 2.93. On the other hand, only 394 insects belonging to 32 species were reported from the intensive orchard. As regards the flora, 10 species were identified in the extensive orchard, allowing several insect species to become established as opposed to the intensive orchard. Finally, the preliminary monitoring of CTV and its vectors in the same orchards led for the first time to detect CTV in the Mina Valley.
Supervisor:
S. Ali Arous and K. Djelouah
Collaboration:
CIHEAM