Microbiological control effects on sucking insects in three citrus management pest systems / Efeito do controle microbiano em insetos sugadores em três sistemas de manejo de pragas de citros

AUTOR(ES)
DATA DE PUBLICAÇÃO

2007

RESUMO

This present work was developed with 22 sucking insect species and their controllers in citrus orchard, at Cambuhy Farm, Matão County, São Paulo State, Brazil., during the period of November 2004 - April 2006. At first, the ecological indexes were determined for that agroecosystem and the evaluation of species diversity in three control systems was performed: microbiological pest management (MPM) only with the entomopathogenic fungus use, ecological pest management (EPM) with selective pesticides use, and integrated pest management (IPM) with pesticides standard use. The higher diversity was found in MPM; EPM and IPM were similar (80%), and there were no environmental impact in all three systems, as a function of the periods of observation. Orthezia praelonga, in six season periods, was kept under control in MPM and EPM by Syngliocladium sp. and Lecanicillium longisporum fungi, with higher prevalence of both entomopathogens at different seasons. Dialeurodes citri was the mean host of Aschersonia aleyrodis with more than 80% incidence of the pathogen. In EPM system, it was observed the reverse association between O. praelonga population and the number of colony formation units (CFU) of Lecanicillium, when to a bigger pest population a lower colony number in soil was observed. For the MPM treatment a direct association was determined, being the biggest pest mortality correlated to the biggest CFU of Lecanicillium, indicating soil potential as inoculum reservoir to primary disease focus formation, not being influenced by pesticides application in the system. In IPM system, pest mortality caused by Syngliocladium had a inverse association with the potential CFU production of Lecanicillium, being pest management conditions favorable to the action of this fungus. Complete biological cycle of L. longisporum (ESALQ isolate-1300) in O. praelonga was 96-144 hours, as determined by electronic microscopy, causing death after 24 hours inoculation. Also, it was studied the influence of abiotic factors on the population and sucking insects mortalities, as a function of cultural practices and inoculums production by prevalent entomopathogenic fungi.

ASSUNTO(S)

insetos sugadores citrus pest management citricultura impactos ambientais pragas de plantas. syngliocladium sp cochonilhas controle biológico (fitossanidade) orthezia praelonga. environmental impact lecanicillium longisporum fungos entomopatogênicos

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