Assessment of a more conservative stink bug economic threshold for managing stink bugs in Brazilian soybean production

• Decreasing stink bug ET for soybean management increased insecticide applications.
• Reduced stink bug ET use did not increase yield, net income or bean quality.
• Current stink bug ET is safe, regardless of soybean cultivars (different growth).

The objective of this study was to assess the stink bug economic threshold for soybean integrated pest management decisions. For this purpose, a replicated experiment was implement in a commercial soybean crop located in Arapongas, Parana State, Brazil, during two crop seasons: 2010/2011 and 2011/12. Treatments consisted of different stink bug densities triggering the application of insecticides, ¼ of the economic threshold (ET) (= 0.5 stink bugs m−1) and ET (= 2 stink bugs m−1), and without applying an insecticide (control). The stink bugs were quantified weekly and all specimens were identified to the species level. At harvest, yield and quality of the seeds were also measured. In all crops, Euschistus heros was the most abundant species. The highest yield and percentage of viable seeds were found in the 'BMX Power RR′ cultivar (indeterminate growth cultivar), indicating a better seed quality. At the end of the experiment, there was no observed difference in yield between different stink bug management thresholds, indicating the effectiveness of the control when adopting ET. This study demonstrates that decreasing the economic threshold increased the number of required insecticide applications, but did not increase yield or bean quality neither the net income when an economic analysis was performed.

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