Chemical Composition of Essential Oils from Rosmarinus officinalis L and Acridicide Activity on Dociostaurus maroccanus Thunberg, 1815 in Morocco [ ]

This work aims to study the chemical composition of essential oils from Rosmarinus officinalis L. samples collected in spring in Moyen-Atlas (Morocco) and to test their insecticide activity on survival of the pest locust Dociostaurus maroccanus. These essential oils are characterized by the presence of 1,8-cineole (42,24%), α-pinene (16,31%), camphor (10.81%), sabinene (8,64%) and myrtenol (5,01%) as major compounds. Comparative analyses among plants collected in different countries evidenced 4 well defined chemotypes, associated to more or less extended territories. Our extract was active against locusts, as estimated by the determination of the LT50 (lethal time 50). LT50 obtained was around 2.25 days for females and 1.9 days in males. This effect can be attributed to one or several compounds of the extract. Given the high humidity of produced faeces, disturbance of water intake by rectum seems to be the most probable cause of mortality.