Occurrence of Erwinia amylovora on insects in a fire blight orchard

In order to screen for natural dissemination of fire blight under field con ditions, insects were caught in an experimental orchard and assayed on semi -selective agar plates and by BIO-polymerase chain reaction for their conta mination with Erwinia amylovora, the causative agent of the bacterial disea se. The pathogen was detected on 15 out of 348 insects collected (4.3%). Th e insects contaminated with E. amylovora have different living habits and b elong to four different orders (Homoptera, Coleoptera, Hymenoptera and Dipt era) and at least eight insect families (Aphididae, Psyllidae, Coccinellida e, Curculionidae, Ichneumonidae, Formicidae, Apidae, and Muscidae) and to o ther Brachycera. After contact of insects with E. amylovora, the pathogen c ould survive at least 5 days in/on the green lacewing (Chrysoperla carnea) and 12 days on aphids (Aphis pomi).