Interactions between aphids and aphidophages in citrus orchards in the Chlef region (North West of Algeria)

Abstract

The objective of this study is to inventory and identify the different species of aphids and aphidophages associated with them in citrus orchards in the Chlef region (Algeria) in order to promote predation and parasitism interactions for the ultimate purpose of biological control of these formidable pests. Surveys are conducted twice a month for an entire year. For sampling, we used yellow sticky traps, yellow pans, and visual determination. This study allowed us to identify seven species of aphids and 34 species of aphidophages, including 30 predator species and 4 parasitoid species. The most abundant aphids are Aphis spiraecola (Patch, 1914) and Aphis gossypii (Glover, 1877), while the most common aphidophages are Episyrphus balteatus (De Geer, 1776), Chrysoperla carnea (Stephens, 1836), Coccinella septempunctata (Linné, 1758), Aphidoletes aphidimyza (Rondani, 1847) and Lysiphlebus fabarum (Marshall, 1896). In terms of frequency, aphidophages are dominated by ladybugs, followed by lacewings, then syrphids, then bugs, and aphid midges in last place. The diversity of the aphidophages fauna is not very important, but the highest values are observed towards the end of April. Predation activities in the study area extend from the end of March to November. Aphidophages associated with aphids are divided into generalists and specialists. Specialist aphidophages show preferences for certain prey over others, in the case of aphid diversity according to both intrinsic and extrinsic factors.

Keywords

• aphids
• aphidophages
• citrus
• natural enemies
• Chlef region