Life Cycle of Bacterial Wilt
Caused by Erwinia tracheiphila
Bacteria enter xylem
vessels of leaf veins
and move down the
petiole and vine.
Bacteria multiply in sap at the
margins of wounds.
Bacteria spread to adjacent vessels
through dissolved cell walls,
clogging vessels of the plant and
causing discoloration of xylem
vessels.
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.
Beetles feed on and
contaminate cucurbit
plants with bacteria.
Bacteria are deposited
with the insect feces on
leaf wounds.
Bacteria continue to multiply,
forming visible masses of ooze.
Bacteria spread to other vines and
plant begins to wilt. Entire plant
wilts and dies.
T. A. Zitter & M.M. Kennelly
Dept. of Plant Path
Cornell University
Ithaca, NY 14853
Photo credits L-R: Author, B.
Bruton, R. Latin, M.
Hoffmann
Bacteria overwinter in the striped and spotted cucumber
beetles. Beetles usually appear when plants emerge in spring.