Parasitism of secondary-stage juvenile of Heterodera glycines and four larva stages of Caenorhabditis elegans by Hirsutella spp

The fungi Hirsutella rhossiliensis and Hirsutella minnesotensis generally parasitize only plant-parasitic nematodes in nature but parasitize the bacterivorous nematode Caenorhabditis elegans on agar plates. To establish a model system for studying the interaction between fungi and nematodes, we compared the parasitism of the first- to fourth-stage larvae (L1-L4) of C elegans and second-stage juvenile (J2) of Heterodera glycines by twenty isolates of Hirsurella spp. Although parasitism differed substantially among isolates, both H. minnesotensis and H. rhossiliensis parasitized a higher percentage of H. glycines J2s than of C. elegans larvae. Parasitism of C. elegans L1s was correlated with parasitism of H. glycines J2s. Parasitism of C elegans by H. rhossiliensis and H. minnesotensis was negatively correlated with larva size and motility, i.e., parasitism was higher for the younger stages. The C elegans L1 is recommended for studying parasitism of nematodes by H. rhossiliensis and H. minnesotensis. (C) 2013 Elsevier Inc. All rights reserved.