Selectivity of agrochemicals used in São Paulo State citriculture to Trichogramma atopovirilia Oatman &Platner, 1983, for the control of citrus fruit borer, Gymnandrosoma aurantianum Lima, 1927 / Seletividade a Trichogramma atopovirilia Oatman &Platner, 1983 de agroquímicos utilizados na citricultura paulista para o controle do bicho-furão-dos-citros, Gymnandrosoma aurantianum Lima, 1927

AUTOR(ES)
DATA DE PUBLICAÇÃO

2008

RESUMO

This study sought to evaluate in the laboratory the selectivity of chemical products used in citriculture to the egg parasitoid Trichogramma atopovirilia Oatman &Platner (Hymenoptera: Trichogrammatidae), the natural enemy with the greatest potential for use in the biological control of Gymnandrosoma aurantianum Lima (Lepidoptera: Tortricidae), one of the main pests of citrus. Assays were conducted following the standards established by IOBC/WPRS to evaluate the harmful effects of agrochemicals to natural enemies of insects. Distilled water was used as a control and five insecticides (imidacloprid, deltamethrin, Bacillus thuringiensis, mineral oil, and triflumuron), three miticides (abamectin, dicofol, and spirodiclofen), and four fungicides (copper oxychloride, pyraclostrobin, difenoconazole, and mancozeb) used to control the citrus fruit borer and other pests and diseases of citrus were selected as treatments. Assays were conducted to study adult (the most susceptible stage of the parasitoid) exposure to the products; direct contact with immature forms (egg-larva, prepupa, and pupa) inside eggs of the natural host G. aurantianum and of the factitious host, Anagasta kuehniella; and acceptance, by females of the parasitoid, of eggs treated with the products. The products were then classified with regard to the reduction caused in parasitism or emergence percentage, into: 1, harmless (<30%); 2, slightly harmful (30 to 79%); 3, moderately harmful (80 to 99%); and 4, harmful (>99%). The insecticides, miticides, and fungicides tested affected T. atopovirilia parasitism. No differences were observed in T. atopovirilia behavior reared either on the natural or on the factitious host. The least selective products to parasitoid adults were deltamethrin, abamectin, mineral oil, and imidacloprid. As to the immature stages of the parasitoid, all products were harmless, except for mineral oil, which caused a 100% reduction in emergence percentage; abamectin, triflumuron, and imidacloprid were slightly harmful to the egg-larval period. Abamectin and triflumuron had the greatest effect on the parasitism capacity of individuals emerged when the treatment was applied during the parasitoids pupal stage. The products Bacillus thuringiensis, difenoconazole, copper oxychloride, pyraclostrobin, dicofol, spirodiclofen, considered harmless or slightly harmful in all steps of the laboratory assays, can be used in Integrated Pest Management programs, in association with biological control, without being harmful to the parasitoid, and can contribute toward citriculture sustainability.

ASSUNTO(S)

iobc bicho-furão inseticidas biológicos. integrated pest management. controle químico egg parasitoid controle biológico citricultura

ACESSO AO ARTIGO

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