This work was carried out in the 1991, 1992 and 1994 growing seasons, in Cruz Alta, Rio Grande do Sul State. The objective was to evaluate the infestation levels and damage of Diloboderus abderus (Sturm) in wheat under no-tillage. Infestations above 5.0 larvae/m² caused significant reductions on yield when compared to uninfested plants. Increasing number of larvae/m² increased damaged plants with decreased plant population, number of ears, plant biomass and yield. Control levels were of 5.4 in 1991, 3.0 in 1992 and 6.1 larvae/m² in 1994. Significant negative correlations were observed between number of larvae and plant population, number of ears, plant biomass and yield. Significant positive correlations were obtained between yield and plant population, number of ears and plant biomass. Results of the insect damage suggested the control level of 5.0 larvae/m² as indicator for wheat seed treatment with insecticides.
Insecta; larvae; damaged plants; Triticum aestivum
