Résumé:
This study aims to determine the efficacy of the treatment of Tuta absoluta (Meyrick) known as tomato leafminer with the bio-insecticide of plant origin derived from zonal pelargonium extraction in the Mostaganem region. The extraction yield obtained is 3.6%. The experiment revealed that the aqueous extract of P. zonal can constitute a very interesting means of control because it recorded a high toxicity of more than (80%) against the larvae L1 of T. absoluta in a short time and with low concentration. On the other hand, the studied plant requires an LD50 which exceeds 32% and an LD90 exceeds 52.71% to kill 50 and 90% of the treated insects.