Life Cycle of Bacterial Wilt
Caused by Erwinia tracheiphila Originally produced as a poster by T.A.Zitter and M.M.
Kennelly
Department of Plant Pathology, Cornell University, Ithaca NY
Bacteria
enter xylem vessels of leaf veins and move down the peitole and vine.
Bacteria spread to adjacent vessels through dissolved cell
wall, clogging vessels of the plant and causing discoloration of the xylem
vessels.
Bacteria
continue to multiply, forming visible masses of ooze.
Bacteria
multiply in sap at the margins of wounds.
Beetles
lay eggs near young plants and larva attack plant roots. Larvae pupate in soil
and emerge as adults usually in August. Emerging adults become contaminated
with bacteria upon feeding on infected plants.
Bacteria
spread to other vines and plant begins to wilt. Entire plant wilts and dies.
Beetles
feed on, and contaminate cucurbit plants with bacteria. Bacteria are deposited
with the insect feces on leaf wounds.
Bacteria
overwinter in the stripped and spotted cucumber beetles. Beetles usually appear
when plants emerge in spring.