Mortalidade do ácaro predador Neoseiulus californicus (Acari: Phytoseiidae) em testes de toxicidade residual de inseticidas e acaricidas usuais em pomáceas
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Data
2008-12-01
Autores
Ruiz, Marcelo Gustavo [UNESP]
Moraes, Gilberto José de
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Editor
Sociedade Brasileira de Fruticultura
Resumo
Os ácaros fitoseídeos, especialmente Neoseiulus californicus (McGregor), são importantes agentes de controle biológico de ácaros tetraniquídeos-praga nas culturas de pomáceas no Alto Valle del Río Negro y Neuquén, Argentina. Neste trabalho, avaliou-se a mortalidade de N. californicus quando exposto a resíduos dos inseticidas azimphos-methyl, carbaryl e cyfluthrin, e dos acaricidas cyhexatin e propargite. Os produtos foram aplicados às concentrações recomendadas em plantas de pereira. Um, três, seis e dez dias após a aplicação (DAA), folhas tratadas foram retiradas das plantas para a preparação de unidades experimentais. Cinco adultos de N. californicus, provenientes de criação-estoque, foram transferidos para cada unidade, onde pólen de taboa foi fornecido como alimento. As unidades foram mantidas a 25 ± 2 ºC, 60 ± 10% de umidade relativa e fotoperíodo de 14 h. A mortalidade do ácaro foi avaliada 24 h após o confinamento. As médias de mortalidade foram comparadas pelo teste de Dunnett, a 5% de probabilidade. A progressão do declínio do efeito dos produtos testados foi submetida à análise de regressão. Nas duas primeiras datas de avaliação, todos os produtos apresentaram valores de mortalidade significativamente diferentes da testemunha tratada com água. Seis dias após a aplicação, propargite, cyhexatin e cyfluthrin apresentaram mortalidade de aproximadamente 30%, enquanto a mortalidade nos tratamentos azimphos-methyl e carbaryl apresentou níveis estatisticamente similares aos da testemunha. Dez dias após a aplicação, a mortalidade em todos os tratamentos não diferiu significativamente da testemunha. O efeito de todos os produtos apresentou declínio progressivo ao longo do período de observação, sendo significativa a 1% de probabilidade a regressão linear negativa para os valores obtidos. Os maiores efeitos negativos sobre a sobrevivência de N. californicus corresponderam aos acaricidas testados. Azimphos-methyl foi o produto que menos afetou a sobrevivência do ácaro predador. Os inseticidas testados, usados na região do Alto Valle del Río Negro y Neuquén para o controle de Cydia pomonella, praga-chave das culturas de pomáceas, apresentaram baixa toxicidade sobre N. californicus.
Phytoseiid mites, mainly Neoseiulus californicus (McGregor), are important biological control agents of Tetranychidae pest mites in pip fruit crops in the region known as Alto Valle del Río Negro y Neuquén, Argentina. We assessed the mortality of N. californicus when exposed to residues of the insecticides azimphos-methyl, carbaryl and cyfluthrin, as well as the acaricides cyhexatin and propargite. Pear plants were sprayed up to dip-point with pesticides in their recommended label concentrations. One, 3, 6 and 10 days after application (DAA), leaves were collected from treated plants and used to establish experimental arenas. Five adult laboratory-reared N. californicus specimens were transferred into each arena which contained Southern cattail pollen as food source. Experimental arenas were kept at 25 ± 2 ºC, 60 ± 10% RH and a photoperiod of 14 hours. Mite mortality was assessed 24 hours after the confinement. The completely randomized design was adopted for data statistical analysis, mortality means were compared by Dunnett's test (p < 0.05). Progression of pesticide's effect decline was submitted to regression analysis. on 1 and 3 DAA mean mortality in all of the treatments was significantly different from that of the water-treated control. on the sixth DAA, propargite, cyhexatin and cyfluthrin treatments caused about 30% mortality, while mortality levels in treatments with azimphos-methyl and carbaryl were statistically similar to that of control treatment. on the tenth DAA, mortality in none of the pesticide treatments differed from that of control. All of the pesticide treatments presented progressive decline throughout the experimental period, being significant (p < 0.01) the negative linear regression obtained. Tested acaricides produced the greatest negative effects on the survival of N. californicus. Azimphos-methyl was the pesticide that least affected the survival of the predatory mite. Tested insecticides, used in the Alto Valle del Río Negro y Neuquén region to control codling moth, C. pomonella, key pest of pip fruit crops, showed low toxicity to N. californicus.
Phytoseiid mites, mainly Neoseiulus californicus (McGregor), are important biological control agents of Tetranychidae pest mites in pip fruit crops in the region known as Alto Valle del Río Negro y Neuquén, Argentina. We assessed the mortality of N. californicus when exposed to residues of the insecticides azimphos-methyl, carbaryl and cyfluthrin, as well as the acaricides cyhexatin and propargite. Pear plants were sprayed up to dip-point with pesticides in their recommended label concentrations. One, 3, 6 and 10 days after application (DAA), leaves were collected from treated plants and used to establish experimental arenas. Five adult laboratory-reared N. californicus specimens were transferred into each arena which contained Southern cattail pollen as food source. Experimental arenas were kept at 25 ± 2 ºC, 60 ± 10% RH and a photoperiod of 14 hours. Mite mortality was assessed 24 hours after the confinement. The completely randomized design was adopted for data statistical analysis, mortality means were compared by Dunnett's test (p < 0.05). Progression of pesticide's effect decline was submitted to regression analysis. on 1 and 3 DAA mean mortality in all of the treatments was significantly different from that of the water-treated control. on the sixth DAA, propargite, cyhexatin and cyfluthrin treatments caused about 30% mortality, while mortality levels in treatments with azimphos-methyl and carbaryl were statistically similar to that of control treatment. on the tenth DAA, mortality in none of the pesticide treatments differed from that of control. All of the pesticide treatments presented progressive decline throughout the experimental period, being significant (p < 0.01) the negative linear regression obtained. Tested acaricides produced the greatest negative effects on the survival of N. californicus. Azimphos-methyl was the pesticide that least affected the survival of the predatory mite. Tested insecticides, used in the Alto Valle del Río Negro y Neuquén region to control codling moth, C. pomonella, key pest of pip fruit crops, showed low toxicity to N. californicus.
Descrição
Palavras-chave
Controle biológico, Manejo Integrado de Pragas, Seletividade, Pomáceas, Biological Control, Integrated Pest Management, Selectivity, Pip fruit
Como citar
Revista Brasileira de Fruticultura. Sociedade Brasileira de Fruticultura, v. 30, n. 4, p. 919-924, 2008.