Brazilian Helicoverpa armigera fought with more selective pesticides

Brazilian farmers should look more carefully for more selective pesticides for controlling of Helicoverpa armigera during early stages of soybean planting, said the researcher Daniel Ricardo Sosa Gomez, from EmbrapaSoja (Brazilian Enterprise for Agricultural Research) in Parana.
 
Studies indicate that the best result is obtained when using "products that do not affect other natural enemies. These products could be based on biological control, for example. The ideal is to make a detailed work in each region with different products in different doses in order to evaluate applications, whether they have an impact on natural enemies or not. Probably this study will be made by Embrapa next season,"he said in an interview at Agrodebate.
 
Gomez commented on products containing the active ingredient emamectin benzoate, long claimed by producers, but already used in other countries against Helicoverpa armigera.”It is a very toxic product that deserves to be treated very carefully. When applying broad-spectrum insecticides, an imbalance occurs , and secondary pests  may appear. If you use the defensive inappropriately it can cause negative side effects. Certain products favor the mite population, others caterpillars. You have to prefer more selective products.
 
The researcher further explains field handling producers need to have to prevent and mitigate plague impacts. "Initially, you should monitor. For soybean, you put a cloth between the plants rows and beat up on one side. The caterpillars that fall on the cloth are counted and it represents the density of insects in crops," he explains.
 
"But sometimes the caterpillar attacks early small plants and the farmer has to examine them, quantify the different sampling points and see how many are present per meter. After this test you have to decide if you need a control measure or not. It is important not to mix up the different types of caterpillars and it is necessary to identify them appropriately. If found four small larvae (less than 1.5 cm) per meter of row, it is time to start the control," he explains.