Valorisation of the Effects of Bioactive Compounds of the Ethanolic Extract of Ramalina Farinacea (Ramalinaceae) on the Development, Eating and Pupation Behavior of Drosophila Melanogaster (Diptera: Drosophilidae)

Plants are rich in bioactive chemical secondary metabolites and have proven insecticidal activity by killing or repelling insects. In this work, we aim to evaluate the direct and delayed effects of ethanolic plant extracts on the vinegar fly (Drosophila melanogaster). The treatment was performed by ingestion on second instar larvae (L2) to evaluate the impact of the ethanolic extract on development for 15 days and subsequently on the feeding behavior of the larvae. The results of this study indicate a slowing down of pupal growth until the adult stage, at the three concentrations (0.25 µg/ml, 0.5 µg/ml, 1.5 µg/ml, 2 µg/ml) used. The results also showed that after three days of treatment, third instar D. melanogster larvae lost the ability to detect the odors of their nutrient environments. Other numbers of larvae (34 %) do not make a choice in the different tests performed. This study indicates that the ethanolic extract of Ramalina farinacea has a neurotoxic property our results confirmed the presence of toxic secondary metabolites which have bioinsecticidal activities in this extract.