VIEW ARTICLE

Ecology and Epidemiology

Ingestion-Egestion and Aerial Transmission of Pythium aphanidermatum by Shore Flies (Ephydrinae: Scatella stagnalis). N. P. Goldberg, Graduate research associate, Department of Plant Pathology, University of Arizona, Tucson 85721; M. E. Stanghellini, professor, Department of Plant Pathology, University of Arizona, Tucson 85721. Phytopathology 80:1244-1246. Accepted for publication 21 May 1990. Copyright 1990 The American Phytopathological Society. DOI: 10.1094/Phyto-80-1244.

Aerial transmission of Pythium aphanidermatum by shore flies (Scatella stagnalis) is documented for the first time. Shore flies, which were thought to feed only on blue-green algae and diatoms, also fed on cucumber roots colonized by the fungus. Ninety-seven percent of the first and second instar larvae, 20% of pupae/third instar larvae, and 10% of adult flies carried mature oospores in their gut. Oospores excreted by larvae and adults were capable of germinating. P. aphanidermatum was transmitted to healthy cucumber plants by naturally infested larvae and adult flies. Adult flies infested with P. aphanidermatum may account for pathogen introduction and spread within commercial greenhouse facilities.