Toxicity of insecticides for adults of Diceraeus melacanthus Dallas, 1851 (Hemiptera: Pentatomidae) in three exposure modes
¹Universidade da Grande Dourados, Entomologia e Conservação da Biodiversidade, Departamento de Entomologia. Rodovia Dourados – Itahum, km 12, Cidade Universitária, Mato Grosso do Sul, Brasil
²Embrapa Agropecuária Oeste, Rodovia BR 163, km 253, Dourados, Mato Grosso do Sul, Brasil
*Correspondence: elizete.cavalcanteufgd@gmail.com
Abstract:
Phytophagous stink bugs are considered the important pest in second-crop corn cultivation in Brazil, especially when they occur during the early stage of plant development. This study aimed to evaluate the efficiency of insecticides in controlling adults of the Diceraeus melacanthus (Dallas, 1851) stink bug when applied separately in three different modes of exposure. The treatments were evaluated in three modes of exposure of insecticides to D. melacanthus adults as described below: direct contact (direct application of the insecticide to the insects); tarsal contact (exposure through their walking on the treated surface) and ingestion (contact through their feeding on previously treated fresh bean pods). Mortality was assessed at 1, 5, 24 and 48 hours post-exposure. We observed that the percentage of accumulated mortality of D. melacanthus adults was significant through direct contact with chemical treatments. However, if the target insect does not receive direct spraying on its body, indirect contact through its tarsus walking on the treated surface can guarantee a significant final mortality of the stink bugs. In addition, although the mode of exposure through ingestion has shown low mortality, it may also contribute to the final mortality of stink bugs in the field depending on the chemical treatment applied to the crop.
Key words:
chemical control, green belly stink bug, mortality, neonicotinoids