Erwinia Chrysanthemi - Environment

Environment

D. dadantii is a pathogen that is spread through water with the splashing of water from infected plants or recycled irrigation water, insects and cultural practices, such as using contaminated tools and machinery or improper storage of vegetables or seeds with infected substances. Insects are an important vector for movement of the pathogen. Insects are able to carry the bacteria externally and internally and are normally unharmed by the bacteria. However, there is continued research in the area of D. dadantii as an insect pathogen to aphids. The pea aphid is able to contract the pathogen from an infected plant and is destroyed in a mode of action similar to Bacillus thuringiensis by producing cyt-like entomotoxins that cause septicemia. The most important factor to disease development is environmental factors consisting of high humidity and temperatures of 71° to 93°F (22° to 34°C). In greenhouses, D. dadantii can survive in potting media with or without a host plant for a year or more and in the leaves of host or nonhost plants for 5 to 6 months.