Activités biologiques des feuilles de Peganum harmala (Zygophyllacea) en floraison sur la mortalité et l'activité génésique chez le criquet pèlerin Biological activities of Peganum harmala (Zygophyllacea) leaves at floral stage on the mortality and reproductive activity of the desert locust

The effects of Peganum harmala leave extracts at floral stage of the plant on desert locust mortality, feeding behaviour and reproductive activity were studied under laboratory conditions. Results indicate that this extract caused a mortality rate of 75% on the fifth hopper instars, reached on the 14 day after beginning of treatment and 45% on the adults females on the 16 day at the imaginal life. Furthermore, we have noted in all treated insects (hoppers and adults females) a loss of weight, a decrease of food intake and loss of water, which consequently, caused a delay of sexual maturity. A reduction in both fecundity and hatching rate were noted in females surviving the treatment. Equilibrium problems were observed in all treated individuals. The observed disturbances were caused by harmaline and harmine, tow major indolic alkaloids identified in the extract of Peganum harmala leaves at floral stage.