COMPARATIVE EFFECTS OF ARISTOLOCHIC ACIDS, PHENANTHRENE, AND 1,3-BENZODIOXOLE DERIVATIVES ON THE BEHAVIOR AND SURVIVAL OF SPODOPTERA-LITURALARVAE

In a leaf disk choice bioassay against Spodoptera litura larvae, arist olochic acids 2 and 4 showed the strongest antifeedant activity when c ompared to phenanthrene, 1,3-benzodioxole, and reduced aristolochic ac id derivatives. Of the phenanthrene analogs, only phenanthridine had a significant feeding-deterrent activity ata 1% concentration. The resu lts of the diet incorporation bioassay of these compounds at a concent ration of 1000 ppm showed that growth inhibition and survival of S. li tura larvae varied according to the structure and that modifications o f the aristolochic acid structure significantly reduced the anti-insec t activity of the derivatives. Only 3,4-(methylenedioxy)-10-nitrophena nthrene (5) showed severe growth inhibition, while 5-nitro 1,3-benzodi oxole (12) from the 1,3-benzodioxole series had the strongest toxicity . Phenanthridine (14) and phenanthrene (16) were very toxic, while 1,1 0-phenanthroline (15) showed strong growth inhibition. The observed re sults suggest that the differences might be due to different modes of action and that neither the phenanthrene analogs nor the 1,3-benzodiox ole is as active as the natural aristolochic acids.