Toxicity Evaluation of Dittrichia viscosa L’s Aqueous Extracts in Combination with Bio-Adjuvant Silene fuscata on Chaitophorus leucomelas Koch. (Hom., Aphididae) and on Biocenotic Resumption of Functional Groups

Phytosanitary interventions present harmful effects on environment and favour development of noxious insects resisting to active materials. Copious works took an interest to research of alternative methods to pesticides. Our study aim is to increase extracts toxicity of plant with insecticide activity and to evaluate global efficiency of bio-active molecules. Results have shown important effect of aqueous extracts from Dittrichia viscosa on the availability of Chaitophorus leucomelas (Hom., Aphididae) with a moderate resumption under the effect of extracts compared to the action of active substance. Analyses showed that aqueous extract ratio of Dittrichia viscosa / Silene fuscata had an effect more toxic on C. leucomelas compared to aqueous extract of the whole D. viscosa plant and extracts of different organs. Results pointed out the great discrepancy related to the structuring and arrival order of functional groups under different stress. Biocenotic resumption of functional groups was important under biologic stress effect compared to chemical stress.