Bioatividade, dinâmica e residual de neonicotinóides e lambda cialotrina na alimentação de Euschistus heros (Fabricius) (Hemiptera: Pentatomidae) em soja
Data
2022-09-30
Autores
Nakaghi, Adilson Massami
Título da Revista
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
A cultura da soja [Glycine max (L.) Merrill] é a principal commoditie agrícola brasileira. Dentre as inúmeras pragas que podem provocar danos econômicos, o complexo de percevejos se destacam pelo enorme potencial de ocasionar prejuízos. Ao se alimentarem dos grãos, afetam diretamente o rendimento e a qualidade da cultura da soja. Entre as principais espécies está o percevejo-marrom, Euschistus heros (Fabricius) (Hemiptera: Pentatomidae) que possui ampla dispersão e é a espécie mais abundante no Brasil. Dentre os métodos utilizados para o manejo de percevejos na soja, o controle químico ainda é a forma mais eficaz e mais rápida para minimizar os danos à cultura. Ainda que o controle químico seja o mais eficaz no manejo de E. heros, a dinâmica desses produtos nas plantas e pragas ainda é pouco conhecida para várias moléculas. Neste estudo a proposta foi calcular a CL10 e CL25 de alguns inseticidas e entender os possíveis efeitos letais e subletais sobre a alimentação do E. heros. A partir do tempo total de alimentação em 180 minutos, o tempo por punctura dos percevejos foi reduzido em quase 2 vezes pela CL10 da Lambda cialotrina e em até três vezes para as CL10 e CL25 do produto Dinotefuran, superando todos os tratamentos. Quando observada a mortalidade aos 3 dias após a aplicação, destacou-se as CL10 e CL25 Dinotefuran e Tiametoxan apresentando 75,8 e 72,5% de controle, respectivamente. Também foi avaliada a translocação e o período residual de alguns inseticidas na planta de soja, utilizando o próprio E. heros como alvo biológico para as análises de mortalidade. Identificou-se provável movimentação dos inseticidas Dinotefuran + Lambda cialotrina e Tiametoxan + Lambda cialotrina tanto pelo xilema quanto pelo floema pois ambos mostraram controle tanto no estrato inferior como no superior das plantas de soja. Nas análises de cromatografia líquida juntamente com o espectrômetro de massas foi verificado nas folhas que não houve translocação para os estratos da planta onde não foram aplicados os tratamentos, sugerindo novos estudos de translocação em vagens pois é a principal fonte de alimentação dos percevejos. Bons resultados também foram apresentados pelos produtos Dinotefuran + Lambda cialotrina e Tiametoxan + Lambda cialotrina no ensaio de avaliação residual, juntando-se a eles o produto Sulfoxaflor que apresentou efeito de choque. No ensaio de danos aos grãos concluiu-se que todos os tratamentos utilizados foram superiores à testemunha, sendo viável a utilização deles no manejo de percevejo-marrom na cultura da soja.
The soybean crop [Glycine max (L.) Merrill] is the main Brazilian agricultural commodity. Among the numerous pests that can cause economic damage, the stink bug complex stands out for its enormous potential to cause damage. Feeding on the grains, directly affect the yield and quality of the soybean crop. Among the main species is the neotropical brown stink bug, Euschistus heros (Fabricius) (Hemiptera: Pentatomidae), which has a wide dispersion and is the most abundant species in Brazil. Among the methods used to manage stink bugs in soybeans, chemical control is still the most effective and fastest way to minimize damage to the crop. Although chemical control is the most effective way to manage E. heros, the dynamics of these products in plants and pests are still poorly known for several molecules. In this study, the proposal was to calculate the LC10 and LC25 of some insecticides and understand the possible lethal and sublethal effects on E. heros feeding. From the total feeding time of 180 minutes, the time per puncture of the bugs was reduced by almost 2 times for the LC10 of Lambda-cyhalothrin and by up to three times for the LC10 and LC25 of the Dinotefuran product, surpassing all treatments. When mortality was observed 3 days after application, LC10 and LC25 Dinotefuran and Thiamethoxan stood out, presenting 75.8 and 72.5% of control, respectively. The translocation and the residual period of some insecticides in the soybean plant were also evaluated, using E. heros itself as a biological target for mortality analyses. A probable movement of the insecticides Dinotefuran + Lambda-cyhalothrin and Thiamethoxan + Lambda-cyhalothrin was identified both through the xylem and the phloem since both showed control in the lower and upper stratum of soybean plants. In the analysis of liquid chromatography together with the mass spectrometer, it was verified in the leaves that there was no translocation to the strata of the plant where the treatments were not applied, suggesting new studies of translocation in pods as it is the main source of food for the bugs. Good results were also presented by the products Dinotefuran + Lambda-cyhalothrin and Thiamethoxan + Lambda-cyhalothrin in the residual evaluation test, adding to them the product Sulfoxaflor, which presented a shock effect. In the grain damage test, it was concluded that all treatments used were superior to the control, making it feasible to use them in the management of neotropical brown stink bugs in soybean crops.
The soybean crop [Glycine max (L.) Merrill] is the main Brazilian agricultural commodity. Among the numerous pests that can cause economic damage, the stink bug complex stands out for its enormous potential to cause damage. Feeding on the grains, directly affect the yield and quality of the soybean crop. Among the main species is the neotropical brown stink bug, Euschistus heros (Fabricius) (Hemiptera: Pentatomidae), which has a wide dispersion and is the most abundant species in Brazil. Among the methods used to manage stink bugs in soybeans, chemical control is still the most effective and fastest way to minimize damage to the crop. Although chemical control is the most effective way to manage E. heros, the dynamics of these products in plants and pests are still poorly known for several molecules. In this study, the proposal was to calculate the LC10 and LC25 of some insecticides and understand the possible lethal and sublethal effects on E. heros feeding. From the total feeding time of 180 minutes, the time per puncture of the bugs was reduced by almost 2 times for the LC10 of Lambda-cyhalothrin and by up to three times for the LC10 and LC25 of the Dinotefuran product, surpassing all treatments. When mortality was observed 3 days after application, LC10 and LC25 Dinotefuran and Thiamethoxan stood out, presenting 75.8 and 72.5% of control, respectively. The translocation and the residual period of some insecticides in the soybean plant were also evaluated, using E. heros itself as a biological target for mortality analyses. A probable movement of the insecticides Dinotefuran + Lambda-cyhalothrin and Thiamethoxan + Lambda-cyhalothrin was identified both through the xylem and the phloem since both showed control in the lower and upper stratum of soybean plants. In the analysis of liquid chromatography together with the mass spectrometer, it was verified in the leaves that there was no translocation to the strata of the plant where the treatments were not applied, suggesting new studies of translocation in pods as it is the main source of food for the bugs. Good results were also presented by the products Dinotefuran + Lambda-cyhalothrin and Thiamethoxan + Lambda-cyhalothrin in the residual evaluation test, adding to them the product Sulfoxaflor, which presented a shock effect. In the grain damage test, it was concluded that all treatments used were superior to the control, making it feasible to use them in the management of neotropical brown stink bugs in soybean crops.
Descrição
Palavras-chave
Percevejo marrom, Controle químico, Comportamento alimentar, Translocação, Piretróide, Neotropical brown stink bug, Chemical control, Eating behavior, Translocation, Pyrethroid