Control of the german cockroach Blattella germanica with Metarhizium anisopliae and insect growth regulators. / Controle de Blattella germanica (L.) com Metarhizium anisopliae e inseticidas reguladores de crescimento.

AUTOR(ES)
DATA DE PUBLICAÇÃO

2005

RESUMO

It was evaluated the effect of Metarhizium anisopliae and the insect growth regulators triflumuron and pyriproxifen for adults and nymphs of the German cockroach Blattella germanica, and the efficacy of its association in the control of this urban pest. High doses of the pathogen caused high mortality of adults and nymphs. There was no mortality of B. germanica nymphs exposed for 72 hours to the food contaminated with M. anisopliae. The mortality of adults and nymphs was of 93.7% and 82.3%, respectively, when exposed to a surface that had been contaminated with the fungus formulation (5%), as early as 9 days after the application. The LC25 for nymphs exposed for a 72-hour period to the triflumuron-bait was 0.19% (active ingredient) and for pyriproxifen-baits 0.45%, after 15-day period. Both inseticides decreased the production of viable oothecae and the number of nymphs in this cases. Untreated colonies presented 6.55 fold in the number of insects after a 60-day period, with 233.9 average insects per colony. The colonies exposed to triflumuron and pyriproxifen had an average of 60.8 and 81 insects, respectively. The insecticides and fungus association presented populations of 41.8 and 57.7 insects for triflumuron + M. anisolpiae and pyriproxifen + M. anisopliae, respectively. Two applications of the association of M. anisolpiae and triflumuron+pyriproxifen-bait, in an infection chamber, eliminated a cockroach colony in the field. Gregarine-infected insects were more susceptible than healthy ones when treated with the entomopathogenic fungus M. anisopliae and the insect growth regulator triflumuron. More detailed studies on how the insecticides could interfere in the disease process caused by M. anisopliae, and aspects related to the fungus formulation and its contribution to the mortality of German cockroach field populations are still necessary.

ASSUNTO(S)

growth regulators regulador de crescimento baratas urban pest entomopathogenic fungus fungo entomopatogênico controle químico biological control controle biológico praga urbana quimical control cockroach

ACESSO AO ARTIGO

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