The infectivity of eight strains of Steinernema feltiae (Filipjev, 1934) isolated from Southern Italian soils were compared in two laboratory bioassays against Galleria mellonella L. (Lepidoptera: Galleriidae) larvae. Infectivity was determined by larval mortality rate and penetration rate assays. The percentage of larval mortality was recorded after 72-h exposure to infective juveniles (IJs) ranging from 37.7 to 71.1%. In the penetration rate assay the percentage and sex ratio of nematodes invading the insects were determined; the average number of nematodes in cadavers exposed to 100 IJs ranged from 5.23 to 15.80. There were significant differences among the strains and four of them (IS-CL2, IS-GR1, IS-CO1, IS-SA1) were highly virulent to G. mellonella larvae. Bioassays’ results showed a correlation between levels of host mortality and levels of nematode establishment.
Confronto di patogenicità fra otto ceppi di Steinernema feltiae (Filipjev, 1934) (Rhabditida: Steinernematidae) rinvenuti in terreni dell'Italia Meridionale
TARASCO E.
1997-01-01
Abstract
The infectivity of eight strains of Steinernema feltiae (Filipjev, 1934) isolated from Southern Italian soils were compared in two laboratory bioassays against Galleria mellonella L. (Lepidoptera: Galleriidae) larvae. Infectivity was determined by larval mortality rate and penetration rate assays. The percentage of larval mortality was recorded after 72-h exposure to infective juveniles (IJs) ranging from 37.7 to 71.1%. In the penetration rate assay the percentage and sex ratio of nematodes invading the insects were determined; the average number of nematodes in cadavers exposed to 100 IJs ranged from 5.23 to 15.80. There were significant differences among the strains and four of them (IS-CL2, IS-GR1, IS-CO1, IS-SA1) were highly virulent to G. mellonella larvae. Bioassays’ results showed a correlation between levels of host mortality and levels of nematode establishment.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
