Diversity and abundance of insect’s community associated to Argania spinosa (L.) Skeels foliage

Abstract

Argan tree (Argania spinosa) is the unique representative of Sapotaceae family in North-Africa. This family is commonly growing in pantropical areas. The current study focused on the diversity of foliage insect associated to A. spinosa, and their seasonality in four sites in Souss region. Insects were trapped using sticky yellow traps installed on each sampled Argan tree. Consequently, 241 morphospecies were identified represented by seven orders. Hemiptera was the most abundant, followed by Diptera and Hymenoptera. However, the remains orders represented only less than 4%. A high taxonomic richness was recorded for Hymenoptera (100 morphospecies) followed by Diptera (70) and Coleoptera (39). Data analysis shows a quantitative dominance of some insects’ families. Within Hemiptera, Aleyrodidae represented up to 80% of total captures. Coccinellidea was the most abundant family of Coleoptera representing over 62%. Among Diptera and Hymenoptera, more than 60% of total abundance was represented only by five families. Argan foliage insects exhibited seasonal variations. Therefore, high significant diversity parameters were recorded during spring. However, the lowest diversity was recorded during summer in Belfaa and during autumn for the other sites. Five trophic guilds were reported. Their abundance was influenced by seasonal variation. Herbivores abundance was highly significant compared to the others trophic guilds throughout all sampling seasons. Except Ceratitis capitata Wiedemann, which infests argan fruits during the two latest stages of maturity, none of its herbivores is known as economic interest to the argan tree. On the other hand, argan trees host a complex structure of functional taxa, including pest regulating (predators and parasitoids) and pollinators.

Keywords

• Coccinellidea
• herbivores
• Hymenoptera
• insect’s diversity
• parasitoids
• pollinators