Vigilância etmológica e controle biológico de Lutzomyia longipalpis na Cidade de Mossoró, Rio Grande do Norte. / Surveillance etymological and biological control of Lutzomyia longipalpis in the town of Mossley, Rio Grande do Norte.

AUTOR(ES)
FONTE

IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia

DATA DE PUBLICAÇÃO

15/07/2009

RESUMO

The use of biological control with entomopathogenic fungi is a viable alternative to control the vector of visceral leishmaniasis (VL). This study aimed a phlebotomine sandflies survey in Mossoró, Rio Grande do Norte, and its relation with the environmental variables, as well as to evaluate the effects of the fungi, Beauveria bassiana and Metharizium anisopliae var. acridum on the different stages of Lu. longipalpis. Sandfly were captured monthly during one year, in the intra and peridomicile of the houses. The Lu. longipalpis infected by fungi was evaluated in five concentrations from 1x104 to 1x108 conidia/mL, accompanied by negative control (Tween 80 0.05%) and positive control (cypermethrin 196 mg/ml). The unhatched eggs, larvae and dead adults exposed to fungi were sown to reisolate the fungi, analysis of parameters of growth and revalidation by PCR and sequencing. The overall sandflies captured, were 7,347, 94% were Lu. longipalpis. Only temperature affected negatively the density this insects. Infection with B. bassiana reduced by 59% the egg hatch, while M. anisopliae var. acridum reduced in 40%. The larval mortality of sandflies after fungal infection was significantly increased and the longevity of adults was lower than the negative control (p <0.001) for both fungi. The effects of the fungal infection on the hatching of eggs laid by infected females were also significant and inoculum-dependent (p <0.05). On the fungal post-infection growth parameters, for B. bassiana only the germination and sporulation were significantly higher than the fungus before the infection (p <0.001). While for M. anisopliae var. acridum only the vegetative growth was not significant when compared to the fungus before the infection (p >0.05). The revalidation of the identification of the reisolated fungus was confirmed by sequencing post-passage in all insect stages for B. bassiana and only from adult insect for M. anisopliae var. acridum. Thus, Lu. longipalpis the predominant sandflies in Mossoró, represents a serious public health problem because it is the vector of a zoonotic disease endemic in the city. Moreover, B. bassiana was effective against Lu. longipalpis and in terms of infected females fecundity with M. anisopliae var. acridum the results were significant, proving the vector of the VL is susceptible to infection with the entomopathogenic fungi. Consequently, the use of these fungi in phlebotomine control programs has potential as a means of reducing the use of chemical insecticides, resulting in benefits to humans and the environment.

ASSUNTO(S)

leishmaniose visceral lutzomyia longipalpis sazonalidade do vetor controle biológico do vetor fungos entomopatogênicos reproducao animal visceral leishmaniasis lutzomyia longipalpis seasonality of the vector biological control of the vector entomopathogenic fungus

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