03410naa a2200241 a 450000100080000000500110000800800410001910000250006024500750008526000090016030000110016952026470018065000110282765000190283865000170285765000090287465300110288365300230289465300200291765300120293770000200294977301990296914617852004-10-15       1999    bl uuuu     u00u1 u    #d1 aHOFFMANN-CAMPO, C.B.  aGrowth and survival of pest noctuid caterpillars fed on dietary rutin.  c1999  ap.642.  aThe deleterious effect of the flavonol rutin (quercetin3-0-rutinoside) on insects is well known. This flavonol was identified from the soybean genotype PI 227687, one of the most used sources of resistance against several defoliator insects, in a concentration of 0,641% of dry weight. Three experiments were conducted to asses the role of rutin on the growth of Heliothis virescens, Trichoplusia ni, and Anticarsia gemmatalis. Diets, containing different concentrations of rutin, were offered to the larvae from egg hatching to pupation. Rutin negatively affected the survival of H. virescens only when larvae were fed on diet with 2% rutin, being 3.1 times higher than the level found in the PI 227687. The addition of rutin to the diets also effected the feeding time, especially for those larvae fed on diet with 2% rutin, as well as pupal weight decreased significantly. In contrast, after removing the effect of feeding time, statistical differences on pupal weight were no longer observed. Elongation of feeding time was probably the survival strategy used by the larvae, eating small amounts of food, each meal, thus avoiding taking a large amount of toxic compound. Survival of T. ni statistical differences on pupal weight were no longer observed. Elongation of feeding time was probably the survival strategy used by the larvae, eating small amounts of food, each meal, thus avoiding taking a large amount of toxic compound. Survival of T. ni ranged from 100% in the control (no rutin) to 79%, in the highest concentration (2%). A significant main effect of diet was observed on dry pupal weight larvae fed on control and on diets containing 0.25% rutin were heavier than those fed on diets with 0.50% or higher concentrations of flavonol, even after removing the effect of feeding time. Survival of A. gemmatalis was affected by concentrations of rutin. Larvae of A.gemmatalis fed for longer time on a diet containing 1.30% rutin and a significant interactive effect of diet (treatment) and feeding time (covariate) was observed on insect growth. The relationship of pupal weight and feeding time was positive when the larvae consumed contro-diet, indicating that the longer they fed, they became heavier however, the trend was different for insects fed on diet containing rutin; larvae ate for the same time (rutin 0.65%) or longer (rutin 1.30%) but any increase in the pupal weight was observed. These results indicate that. A. gemmatalis, a major defoliator legume specialist, apparently more adapted species, may not be more resistant to rutin than H. virescence and T. ni both poliphagous and circumstantial pests of soybean.  aBrazil  ainsect control  apest control  aSoja  aBrasil  aControle de inseto  aManejo de praga  aSoybean1 aOLIVEIRA, L. J.  tIn: WORLD SOYBEAN RESEARCH CONFERENCE, 6., 1999, Chicago. Proceedings: invited and contributed papers and posters. Chicago: University of Illinois / Soybean Research & Development Council, 1999.