Some pesticides such as pyrethroids insecticides used to fight Helicoverpa armigera are more harmful than helpful because they make their natural predators back away, according to the agronomist Ricardo Heinz.
"The producer needs to be aware that the use of heavy substances, based on pyrethroids, must be stopped. This is because these applications affect not only the caterpillars, but the whole complex of organisms that are living in this area, this means it ends up eliminating the natural enemies", explains the expert.
"I witnessed (in research) several natural enemies that help fight these caterpillars. I saw some of the Helicoverpa infected by these predators that were being eliminated just by the action of these 'enemies' that are present in crops, favoring the producer," concludes Heinz.
A pyrethroid is a synthetic chemical compound similar to natural substances pyrethrins produced by the Pyrethrum phylum flowers (Chrysanthemum cinerariaefolium and C. coccineum). They are common in products such as household insecticides and repellents, as axon poisons that work by keeping sodium channels open in neural membranes of insects.