01679naa a2200181 a 450000100080000000500110000800800410001910000220006024500720008226000090015452011580016365000140132165000130133565300230134870000210137170000230139277300820141511070642002-04-30       1989    bl uuuu     u00u1 u    #d1 aSANTOS, W. J. dos  aEconomic Damage Caused by The Cotton Stem Borer in Southern Brazil.  c1989  aCotton stem borer, Eutinobothurs brasffiensis damage showed a graded distribution from the margin of the field to the middle. Infestation was considerably higher in the: border rows than in the center of the field. The study documented the beliavior of this pest during the period when it migrates from overwintering sites around the field to cotton. The results confirm fórmer observations that: the: levels of infestation are higher near humíd overwintering areas with permanent vegetation. Early planted blocks of cotton had the highest rates of infestation, often reaching 70% of plant mortality. In later plantings a 20% reduction in plant mortality was observed every time planting was delayed for ten days. The data suggest that this pest may be controlled with insecticide applications in border rows. This procedure would eliminate lhe need of chemical treatments which are environmentally unsoutid. The data also suggest that plantíng densitics of nine to tert plants per m would help to reduce: the impact of this pest on cotton yield, The relationship.between yield loss and plant mortality was assessed and the economic damage estimated.  aphenology  asampling  achernical control-1 aGUTIERREZ, A. P.1 aPIZZAMIGLIO, M. A.  tPesquisa Agropecuária Brasileira, Brasíliagv.24, n.3, p. 297-305, mar.1989