Population of Scaptocoris castanea Perty (Hemiptera: Cydnidae) in a crop-livestock integration system

The population of the brown root stink bug, Scaptocoris castanea Perty, was studied in a crop-livestock integration system. This integrated system consisted of corn crop associated with Brachiaria decumbens pasture at the Unidade de Pesquisa e Desenvolvimento, in São José do Rio Preto (49°26' W; 20°49' S), state of São Paulo, Brazil. In each plot of the integrated crop-livestock system, which was consisted of six treatments and four replicates, four 0.25 m(2) and 0.30-m-deep samples of soil and roots were taken for analysis. These samples were stratified in 0.10-m layers, in which the number of nymphs and adults of S. castanea were assessed. These evaluations occurred monthly, from November 2008 to April 2009. The number of brown bug nymphs and adults was higher in areas where corn was cultivated for two consecutive years and in plots where pasture was renewed every 2 years. Lower insect population densities were observed in plots that remained as Brachiaria pasture. Therefore, S. castanea population is larger in integrated crop-livestock system (corn crop associated with B. decumbens), with no tillage.