Évaluation du pouvoir bio-insecticide des extraits bruts d’une espèce halophyte Hammada scoparia de la famille des Amaranthaceae face au Tribolium castaneum de la famille des Ténébrionides.

Abstract

This study investigates the insecticidal potential of phenolic extracts from Hammada scoparia, a desert plant adapted to extreme conditions, collected from two arid regions of Algeria: Ouled Djellal and Ghardaïa. Such harsh environments promote the synthesis of secondary metabolites, especially phenolic compounds known for their diverse biological activities.

A phytochemical screening was conducted to detect the main families of secondary metabolites. Extracts were obtained using various methods: aqueous maceration, hydroalcoholic extraction, infusion, and decoction, followed by quantification of total polyphenol content. Extracts prepared from the aerial parts of the plant via aqueous and hydro methanolic maceration showed a high antioxidant content, particularly rich in flavonoids and gallic acid.

The results showed that the Hammada scoparia species has a total polyphenol content, reaching 99.33 mg EAG/g MVS for sample 01 from Ouled Djellal and 85.87 mg EAG/g MVS for sample 02 from Ghardaia, for the aqueous extract and a higher content for the hydro methanolic extract: 496.89 mg EAG/g MVS for sample 01 from Ouled Djellal and 626.24 mg EAG/g MVS for sample 02 from Ghardaia

The biological activity of the extracts was evaluated against Tribolium castaneum, a beetles of stored food products. Initial toxicity tests, performed via direct contact and spraying on adult insects, resulted in low mortality rates. However, larval bioassays, using contact application, showed significant mortality, dependent on dose and exposure time.

These findings highlight the insecticidal potential of Hammada scoparia extracts, particularly against larvae, and suggest the plant as a promising alternative in biological pest control strategies, potentially reducing the harmful effects of synthetic insecticides on human health and the environment.