Evaluation of the insecticidal properties of Terminalia arjuna ethanolic extracts against Drosophila melanogaster

In this investigation, the dried bark of Terminalia arjuna was extracted with ethanol using Soxhlet extraction and concentrated by vacuum. This crude extract was incorporated into the diet of Drosophila melanogaster larvae in concentrations of 25, 50, and 100 mg/ml to assess any biological effects. At the 100 mg/ml level, a 75 % reduction in larval growth with respect to control larvae was recorded. Additionally, at this dosage, a doubling of time-to-pupation and an average of 90 % mortality was observed. Increased effects were achieved at lower dosage levels by sequentially extracting the bark with hexane, ether, and then ethyl acetate prior to final ethanol extraction. The presence of the suspected active triterpenoids: arjunolic acid, arjunetin, arjungenin, and arjunglucoside were detected by ESI-HRMS.