VIEW ARTICLE

Vector Relations

Conversion of Comovirus Electrophoretic Forms by Leaf-Feeding Beetles. M. A. C. Langham, Department of Plant Pathology, University of Arkansas, Fayetteville 72701; R. C. Gergerich, and H. A. Scott. Department of Plant Pathology, University of Arkansas, Fayetteville 72701 Phytopathology 80:900-906. Accepted for publication 27 March 1990. Copyright 1990 The American Phytopathological Society. DOI: 10.1094/Phyto-80-900.

In vitro and in vivo conversion of comovirus electrophoretic forms by regurgitant of leaf-feeding beetles was demonstrated by agarose gel electrophoresis of virus particles. Converted and unconverted electrophoretic forms of three comoviruses-bean pod mottle, cowpea mosaic, or squash mosaic virus-consistently occurred in either infected tissue or purified virus preparations. Incubation of each virus with regurgitant from Mexican bean beetles, bean leaf beetles, or spotted cucumber beetles changed the form of each virus. Only the converted form was found in regurgitant from beetles that were fed on infected tissue or on purified bean pod mottle virus in 5% sucrose. This conversion is similar to the change that occurs when the virus is incubated with protease solutions. Beetle regurgitant contained approximately ten times more protease activity than bean sap. Bean leaf beetle regurgitant contained more protease than that of the Mexican bean beetle or spotted cucumber beetle.