Happy news amidst the panic that terrible Helicoverpa armigera can spread through crops in Brazil . The dynamics Embrapa Soja , Londrina , Paraná , has just reported that one of its studies show that natural enemies are acting on pest control . It was found , which is even more important .
These studies allow researchers to better understand the behavior of the caterpillar in soybean and perform collections to map the occurrence and increase its inception for scientific purposes .
Part of the collected caterpillars , announces the organ suspected to Helicoverpa armigera were infected or attacked by parasitic nematodes . " The presence of these natural enemies , much like the parasitic nematode , is very important for the balance of the crop , as the crop will develop , because with proper management , the trend is the natural enemy populations grow," explains researcher Clara Beatriz Hoffmann - Campo, Embrapa Soja . " That's why we are strengthening the guidance for the producer to monitor their crops , has criteria for the decision of control and not spray insecticides indiscriminately whether biological or chemical ," adds the researcher .
The survey showed that in some regions , such as the Sierra Maua , in northern Paraná , about 30 % of the collected caterpillars were infected by nematodes , but one nematode well . " At some point , we do not know exactly how it works , the caterpillar is infected by this nematode , which is not the same that attacks the roots of plants ," explains the researcher . In the region of Roncandor the proportion of infected larvae can be further increased. " This alerts us to the importance of good management in the early stage of soybean , for these natural enemies are preserved and kept alive in the field ," he adds .
Warning : Embrapa researchers are cautious about the development of the crop and ensure that , without the action of natural enemies , the situation can be much worse in the field . " In areas where there is an imbalance , the occurrence of pests is much greater , so the existence of natural enemies is important and its preservation is essential because it helps keep pest populations below the action level and delays the occurrence of resistance pest chemicals , "says Beatriz .
The parasitoids are mainly found flies in the family Tachinidae , which develop inside the caterpillar , and the complete development , kill the insect promoting a natural control of the pest . " We found 1-4 per caterpillar parasitoids , which indicates potential multiplier effect of this natural enemy in the field ," he explains . These parasitoids observed in the laboratory are already known to the researchers . They provide the same service environment attacking other species of caterpillars , as Anticarsia and Spodoptera .
According to Clara Beatriz , is very important to have a paradigm shift in the control of pests in agriculture . " It is necessary to review the strategies of control and have a broader view of the production system . We have witnessed pests migrate from one culture to another , increasing rates of insects with chemical resistance , secondary pests becoming a critical issue . There is no other way but to a profound change in posture . Pest control has to be made from recommendations of integrated pest management , ie , from the monitoring and evolution of its occurrence , and never , in a scheduled way , "warns .
Info : www.embrapa.br / Helicoverpa - soy icon publications .
Source : Globo Rural Magazine ( Brazil ) .
Nenhum comentário:
Postar um comentário