Ciência Rural (Jun 2003)
Ação do fungo Beauveria bassiana (Balsamo) Vuillemin, 1912 sobre a fase parasitária do carrapato Anocentor nitens (Neumann, 1897) Schulze, 1937 (Acari: ixodidae) Action of the fungus Beauveria bassiana (Balsamo) Vuillemin, 1912 on the parasitic phase of the tick Anocentor nitens (Neumann, 1897) Schulze, 1937 (Acari: ixodidae)
Abstract
A patogenicidade do fungo Beauveria bassiana (isolado 986) foi avaliada no desenvolvimento da fase parasitária do Anocentor nitens, acompanhando o desenvolvimento de larvas não alimentadas até o estágio adulto. Foram utilizados dois tratamentos e um grupo controle com cinco repetições cada. No tratamento 1 (T1), as orelhas dos bovinos foram banhadas com a suspensão fúngica de 10(8) conídios ml-1; no tratamento 2 (T2), as orelhas foram banhadas com água destilada e espalhante adesivo. No grupo controle (C), as orelhas foram banhadas com água destilada. Após 24 horas dos tratamentos, as orelhas de cada animal foram infestadas com 100mg de larvas. Os parâmetros analisados, em cada tratamento, foram: número e peso de fêmeas recuperadas; períodos de pré-postura, postura, incubação, eclosão e longevidade; percentual de eclosão; peso da massa de ovos e da quenógina; índices de eficiência reprodutiva e nutricional. Verificou-se que, no T1 e T2, o número de fêmeas recuperadas, após 35 dias, foi significantemente menor (PThis study evaluated the pathogenicity of the fungus Beauveria bassiana (Isolate 986) on the development of the parasitic phase of Anocentor nitens by accompanying the development of unfed larvae until the adult stage. Two treated and one control group were used with five repetitions each. In the first treated group (T1), cattle ears were bathed with a fungal suspension of 10(8) conidia ml-1, second treated group (T2), the ears were bathed with distilled water and Tween 80 1% and the control group (C), the ears were bathed with distilled water. One day after treatment, the ears of each animal were infested with 100 mg of larvae. The parameters analyzed in each treatment were: number and weight of females recovered; periods of pre-oviposition, oviposition, incubation, eclosion and longevity; percentage of eggs hatched; weight of the egg mass and of females after oviposition. We found that in the two treated groups the number of females recovered was significantly lower (P<0.05) than in the control group. 35, 70 and 117 females were recovered from the T1, T2 and C, respectively. The females obtained from the surviving larvae of the treated groups did not suffer any deleterious effects from the entomopathogen studied.
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