VIEW ARTICLE

Ecology and Epidemiology

Passage of Verticillium albo-atrum Propagules Through the Alimentary Canal of the Bulb Mite. Douglas W. Price, Assistant Entomologist and Lecturer, Division of Entomology and Parasitology, University of California, Berkeley 94720; Phytopathology 66:46-50. Accepted for publication 9 July 1975. DOI: 10.1094/Phyto-66-46.

Specimens of the bulb mite, Rhizoglyphus echinopus (Acarina: Acaridae), reared on laboratory cultures of Verticillium albo-atrum (microsclerotial strain) in pectate-guanidine agar, produced fecal pellets containing conidia and fragments of microsclerotia. Fecal pellets collected aseptically were used to inoculate agar plates. New V. albo-atrum colonies developed from 76 percent of fecal pellets containing both kinds of propagules, while 92 percent of pellets containing only conidia tested positive for that fungus. Treatments of fecal pellets with dilute sodium hypochlorite solutions and ultraviolet radiation killed conidia in pellets containing both conidia and microsclerotia. Development of V. albo-atrum from treated pellets indicated that the microsclerotial fragments were viable. Mites fed on laboratory preparations of pure microsclerotia produced fecal pellets free of conidia and composed almost entirely of microsclerotial fragments. New V. albo-atrum colonies developed from about 23 per cent of these pellets.