CEPAVE   05420
CENTRO DE ESTUDIOS PARASITOLOGICOS Y DE VECTORES
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Pathogenicity, Biology and Production of the new isolate of Heterorhabditis bacteriophora (Poinar, 1976) (Nematoda: Heterorhabditidae) from Argentina
Autor/es:
ACHINELLY, MARIA F.; ELICECHE, DAIANA P.; CAMINO, NORA
Lugar:
Halifax
Reunión:
Congreso; 2011 International Congress on Invertebrate Pathology and Microbial Control, OECD Symposium on Disease in Aquatic Crustaceans, &44th Annual Metting of the Society for Invertebrate Pathology; 2011
Resumen:
Entomopathogenic nematodes belonging to the Heterorhabditidae are parasites that are lethal to soil-dwelling insects. They are commonly used as biological control agents of insects in cryptic habitats. Entomopathogenic nematodes are cultured in vivo or in vitro. The meal worm Tenebrio molitor has been suggested as an alternative model insect for production and determination of nematode virulence due to the high protein content of the larvae and the fact that this insect is easy to rear and maintain in the laboratory. Here, we provide data from the first evaluation of the pathogenicity of a local strain of the entomopathogenic nematode Heterorhabditis bacteriophora against last instar larvae of Tenebrior molitor. Insects (n=10) were exposed to nematodes at ratio of 500 infective juveniles (J3) per larva. The assays were conducted in petri dish (6 cm diameter) at 25°C. Insect mortality was recorded after 4 days and dead insects were dissected to determine if nematodes were present. Also T. molitor larvae were dissected daily to determine the stage of development of nematodes. Tests, were made in triplicate. Control groups with no J3 stages (10 ml of distilled water only) were included in the study to evaluate spontaneous mortality of the test insect . The time taken to leave the dead host and number of emerged J3 was also evaluated. The results clearly demonstrate the efficiency of. Heterorhabditis bacteriophora causing between 77%-80% mortality against larvae of yellow meal worm. The larvae died between 48 and 72 hours post-infection. We observed two generations of nematodes, a hermaphroditic females, which appeared on day 4 post-infection and anfimíctica day 8, where males and females appeared. Infective forms began to emerge from the bodies the day 11-21 post-infection and continued dating until the day 31-32. Infective forms varied between 3.000 and registered 37.500. On the basis of these results, H. bacteriophora was selected for further evaluation under more field-like conditions. This nematode could be a successful biological control agent by reducing chemical pesticides, the only options used to present to control some of economically important insect pest in Argentina.