Incidence and Distribution of Peach Mosaic and Its Vector, Eriophyes insidiosus (Acari:Eriophyidae) in Mexico. G. N. OLDFIELD, Department of Plant Pathology, University of California, Riverside 92521. R. CREAMER, Department of Plant Pathology; C. GISPERT, Department of Entomology, University of California, Riverside 92521; F. OSORIO and R. RODRIGUEZ, Colegio de Postgraduados, Montecillo, Mexico 56230; THOMAS M. PERRING, Department of Entomology, University of California, Riverside 92521. Plant Dis. 79:186-189. Accepted for publication 4 November 1994. Copyright 1995 The American Phytopathological Society 186. DOI: 10.1094/PD-79-0186.

Foliar and fruit symptoms of peach mosaic disease were observed in peach trees during a study of commercial peach orchards and dooryard peaches in 11 states in Mexico during 1991-1993. Symptomatic trees were discovered in the central highlands of Mexico extending from northern Chihuahua southward to Michoacan and Puebla. Greenhouse-grown Rio Oso Gem seedlings grafted with pieces of bark collected from symptomatic peach trees from seven states developed foliar symptoms of mosaic. The bud-inhabiting mite vector of the mosaic virus, Eriophyes insidiosus, was discovered for the first time in Mexico from buds of wild Prunus munsoniana in Chihuahua and from buds of criollo peaches in the central highland peach-growing areas. On criollo peaches, mites were commonly found in unopened buds along small branches distributed throughout the canopy of the tree, rather than in the adventitious buds typically found on infested commercial varieties of peach in the U.S. Mites from two central Mexican states were naturally inoculative based on positive transmission to greenhouse-grown peach seedlings. An isolate of the pathogen from southern California that causes severe symptoms on Rio Oso Gem peach was transmitted by naturally inoculative field-collected mites to greenhouse-grown criollo rojo, criollo bianco, and criollo naranja seedlings, causing symptoms similar to those found on criollos in the field.

Keyword(s): Prunus serotina capuli