Differential susceptibility of adults and nymphs of Blattella germanica (L.) (Blattodea: Blattellidae) to infection by Metarhizium anisopliae and assessment of delivery strategies
Neotrop. entomol
;
40(3): 368-374, May-June 2011. ilus, tab
Artigo
em Inglês
| LILACS
| ID: lil-591336
ABSTRACT
Microbial insecticides for cockroach control, such as those containing entomopathogenic fungi, may be an alternative to reduce contamination by chemicals in housing and food storage environments. Virulence of isolate ESALQ1037 belonging to the Metarhizium anisopliae complex against nymphs and adults of Blattella germanica (L.), and its infectivity following exposure of insects to a contaminated surface or to M. anisopliae-bait were determined under laboratory conditions. Estimated LD50 15 d following topical inoculation was 2.69 x 10(5) conidia per adult, whereas for nymphs the maximum mortality was lower than 50 percent. Baits amended with M. anisopliae conidia had no repellent effect on targets; adult mortality was inferior to 25 percent, and nymphs were not susceptible. All conidia found in the digestive tract of M. anisopliae-bait fed cockroaches were unviable, and bait-treated insects that succumbed to fungal infection showed a typical mycelial growth on mouthparts and front legs, but not on the hind body parts. As opposed to baits, the use of a M. anisopliae powdery formulation for surface treatment was effective in attaining high mortality rates of B. germanica. Both nymphs and adults were infected when this delivery strategy was used, and mycelia growth occurred all over the body surface. Our results suggest that the development of powders or similar formulations of M. anisopliae to control B. germanica may provide faster and better results than some of the strategies based on baits currently available.
Texto completo:
DisponíveL
Índice:
LILACS (Américas)
Assunto principal:
Controle Biológico de Vetores
/
Blattellidae
/
Metarhizium
Limite:
Animais
Idioma:
Inglês
Revista:
Neotrop. entomol
Assunto da revista:
Biologia
/
ZOOLOGIA
Ano de publicação:
2011
Tipo de documento:
Artigo
País de afiliação:
Brasil
Instituição/País de afiliação:
Embrapa Recursos Genéticos e Biotecnologia/BR
/
USP/BR
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