Scanning electron-microscopic evidence for attachment of a nonpersistently transmitted virus to its vector's stylets

Abstract

A nonpersistently transmitted virus, pea seed-borne mosaic virus (PSbMV) was localized by an indirect immunospecific latex label on stylets of its vectors, the New London and Madison biotypes of potato aphids, Macrosiphum euphorbiae Thomas. On the efficient New London biotype, large quantities of label were observed mostly on the inner surfaces of the mandibles at about 50 μm from the tip. No specific label was found on the mandibular ridges, maxillary projections, food duct, common food chamber, or extraneous materials carried externally on the stylets. The transmissible nature of the virus labeled at 5-min acquisition was confirmed by the decreased labeling with two different inoculation feedings. The sparse label observed on the Madison biotype aphids indicated that this vector was inefficient because insufficient amounts of virus were acquired for effective transmissions.