Controle biológico de imaturos de Bactrocera carambolae (Diptera: Tephritidae) por Metarhizium spp. no Estado do Amapá

Abstract

One of the economically important insect species for the Brazilian fruit production is the carambola fruit fly (Bactrocera carambolae Drew & Hancock), quarantine pest restricted to the time the states of Amapá and Roraima. This pest causes direct damage to the fruits, elevates cost production, besides being considered a phytosanitary barrier to export fresh fruit. In Amapá, fruit production is carried out mostly by farmers and the presence of this pest makes it difficult to place marketing, affecting the generation of employment and income. The objective was evaluate the pathogenicity of isolates of the entomopathogenic fungus Metarhizium spp. on immature B. carambolae under laboratory conditions. Soil samples were collected in the municipalities Oiapoque and Macapá and from these samples were isolated entomopathogen Metarhizium anisopliae and Metarhizium robertsii. In the analysis of which culture medium species of Metarhizium are more sporulation, were tested means Potato-Dextrose-Agar (PDA), Sabouraud-Dextrose-Agar (SDA) and Malt-Extract-Agar (MEA or EMA). To verify mortality 3rd instar larvae of B. carambolae, solutions containing 1x107 conidia/mL of each isolate were used in treatments containing vermiculite, sterile and non-sterile soil. Data were submitted to analysis of variance and Tukey test at 5% probability by the statistical software "R". The isolate of M. anisopliae had highest number of spores in the mean SDA (25,13x107 conidia/mL), while M. robertsii had higher sporulation in PDA (15,53x107 conidia/mL). Regarding mortality of immature B. carambolae, M. anisopliae was higher than M. robertsii for all three substrates. M. anisopliae and M. robertsii, the highest mortality occurred in vermiculite, 54% and 30%, respectively. The results indicated differences in both sporulation and in pathogenicity of isolates of Metarhizium against immature B. carambolae