EFFETS BIOTOXIQUES DES EXTRAITS DE Cleome arabica L. (Capparidaceae) SUR LE CRIQUET PELRIN Schistocerca gregaria (FORSKÅL, 1775) (ORTHOPTERA, ACRIDIDAE)
The study of the toxicity of foliar extract from Cleome arabica L. with respect to the larvae L5 and the imagoes of desert Locust puts forward the biocide power of the extracts tested; a percentage of mortality of 100% is noted at the treated individuals. At the individuals nourished by rags treated by the acetone extract of C. arabica, a percentage of mortality of 76.67% and 86.67% is noted in the male and female larvae respectively, although it is of 100% at the male and female imagoes. In the L5 larvae supplied with rags treated by the alkaloid extract of C. arabica, a mortality rate of 70% is noted in the males and of 63.33% in the females. In the same way, a percentage of mortality of 90% and 100% brought back in respectively the male imagoes and females nourished by rags treated by the alkaloid extract of C. arabica respectively. It should be noted that the values of the percentage of mortality noted, are recorded during the period of experimental follow-up, although the surviving individuals die a few days after this period, following a delayed intoxication. Signs of intoxication are observed at the treated individuals, of which the reduction of the motor activity, intense defecation, water loss unusual in the form of the diarrhea, blocking and/or of the difficulties during moulting. These toxicological demonstrations are accompanied by the reduction by consumption by treated rags, difficulties of digestion and digestive conversion which result in losses of the weight. The study of the digestive histology of tract of the treated individuals shows a reduction of the circular musculature, a hypertrophy of the intestinal mucous membrane, the mesenteral epithelium has a granular appearance and ulcerations are observed.