Effects de la réserpine sur le développement et la croissance de Schistocerca gregaria Forsk. au cours des quatrième et cinquième stades larvaires

Abstract

Various doses of reserpine were injected in the body cavity of fourth-instar nymphal Schistocerca gregaria. Treatment within 48 h from the beginning of the instar significantly increased its duration, whereas treatment at 72 or 96 h did not affect the duration of the fourth stage. However the length of the fifth stage was markedly increased irrespective of the time of treatment in the preceding stage. Fresh body weight of treated larvae increased almost as fast as in the controls. Thus food intake was affected little or not at all by the treatment. In contrast with isolation, reserpine treatment did not affect body pigmentation. Reserpine treatment, destruction of the pars intercerebralis, and isolation were compared with regard to their effects on the molting process