Interaction between the entomopathogenic nematode Heterorhabditis sonorensis and the soilborne fungus Fusarium oxysporum f. sp asparagi: effects on two different insect hosts

The entomopathogenic nematode (EPN) Heterorhabditis sonorensis (Nematoda: Heterorhabditidae) was isolated from Diceroprocta nymphs in an asparagus field in the State of Sonora, Mexico, for future use in an augmentative biological control program. However, 70% of the cicadas collected in the field were found infected with the soil-borne fungus Fusarium oxysporum f.sp. asparagi. The objective of this study was to determine the interaction between H. sonorensis and the soilborne fungus in two different insects hosts, the wax moth Galleria mellonella (Lepidoptera: Pyrallidae) and the corn earworm Helicoverpa zea (Lepidoptera: Noctuidae), and to compare the performance of H. sonorensis in both insect hosts when the soilborne fungus was present. Insect host mortality, EPN establishment in the insect cadaver and EPN progeny production were assessed. Mortality data was corrected using Abbott’s formula. EPN penetration and progeny production were analyzed using ANOVA. Means were compared using Tukey’s test.