Effect of temperature on differential persistence and insect transmission ofErwinia carotovora var.atroseptica andErwinia carotovora var.carotovora

Adult fruit flies (Drosophila melanogaster Meig.) transmittedErwinia carotovora var.carotovora (Jones) Dye (ECC) andErwinia carotovora var.atroseptica (van Hall) Dye (Eca) from vegetative material inoculated with equal proportions ofEcc andEca to uninoculated potato plants and from inoculated potato plants to sterile vegetative material at 15° and 27°C. The insects transmittedEcc andEca with approximately equal frequencies over an 18 hr period at 15°C. At 27°C the proportion ofEcc transmitted was significantly greater thanEca. At 27°C moreEcc thanEca was present in the inoculated vegetative material and potato stems, on fruit flies visiting these sites, and in injured potato tissues to which flies transmitted the bacteria. Results indicate that temperature is important in determining success ofEcc andEca transmission by insects and the relative persistence of the two organisms in plant tissues after transmission.