Pathogenicity of Metarhizium anisopliae (Metchn.) Sorok .on the Blattella germanica (Linnaeus) (Blattodea: Blattellidae) and Periplaneta fuliginosa (Seville) (Blattodea: Blattidae) in Argentina

ALEJANDRA GUTIERREZ; LÓPEZ, P.M.; GARCÍA, J.J; LÓPEZ LASTRA, C

Buenos Aires

Congreso; International Congress on Invertebrate Pathology and Microbial Control, 45th Annual Meeting of the Society for Invertebrate Pathology; 2012

Society for Invertebrate Pathology

Cockroaches, have a worldwide distribution and survive well in association with any human settling. They are important vectors of pathogens that cause disease in animals and humans. Cockroaches are controlled primarily by synthetic organic insecticides. An alternative to chemical methods is the use of entomopathogenic fungi. The isolation of Metharizium anisopliae (Metschnikoff) Sorokin, (Ma) CEP 085 from the culture collection of entomopathogenic fungi of CEPAVE was use. This isolate originally proceed from an unidentified Hemiptera, Cercopidae from Argentina. Pathogenicity was assessed for adults and nymphs (III) of B. germanica and P. fuliginosa. The insects were exposed to conidia of M. a. by direct contact. The conidial suspension of 1x109 spores per milliliter, was applied in Petri dishes with filter paper and cockroach were collocated for 24 hs. The treated cockroaches were placed in plastic containers, were fed with dog food and tap water. The control insects were treated with Tween 80 0.01%, under the same conditions. The bioassay was conducted at 25 ± 2ºC and 70 ± 5% RH. Mortality was controlled daily for 20 day, and dead cockroaches were removed and placed into sterile Petri dishes. The emergence of hyphae was monitored for 8 days. Adults and nymphs of B. germanica were susceptible to Ma 085 infection, with mortality up to 50%. However P. fuliginosa mortality was lower than 25% in adults and nymphs. The differential susceptibility at Ma could be related with the composition of the cuticle in the different species.