Biotemas (Dec 2007)
Pentatomidae bugs associated with sunflower crops in the northwest of Rio Grande do Sul state and the action of Euschistus heros (Fabricius, 1794) (Hemiptera: Pentatomidae) on sunfl ower seeds
Abstract
The goals of this study were to identify the species of bugs attacking sunflowers in the northwest of Rio Grande do Sul state and to estimate the damage caused during the R6 and R8 stages. The bugs present in ten sunflower crops were collected, and their feeding sites were determined. The species Euschistus heros (Fabricius, 1794) was used to determine the damage by individualizing the capitula using mesh cages in the R6 and R8 stages. Each caged capitulum was infested with one, two, or four bugs. Besides E. heros (47.67%), Dichelops furcatus (Fabricius, 1775) (44.18%), Piezodorus guildinii (Westwood, 1837) (4.65%) and Edessa meditabunda (Fabricius, 1794) (3.48%) were found. There were no significant differences among the treatments regarding the yield components (weight of 1000 sunflower seeds, germination power, oil and protein content). The tetrazolio test indicated that the bugs fed on the sunflower seeds.
