Bacterial Wilt
Erwinia tracheiphila
A bacterial disease of cucumbers, melons, and squash that clogs the plant water-conducting tissue and wilts it to death, spread by cucumber beetles. There is no cure once a plant is infected, so the whole battle is keeping the beetles that carry it off the plants. It can wipe out cucumbers and muskmelons especially fast.
🔎 How to spot it
Look for individual leaves, then whole vines, that wilt and collapse, at first recovering overnight but soon wilting permanently and dying, while the rest of the plant may still look green. A simple field test: cut a wilted stem, touch the cut ends together, and slowly draw them apart; sticky, white, stringy ooze stretching between them points to bacterial wilt.
🥀 Damage it causes
The bacteria multiply in and plug the water-conducting tissue, so infected plants wilt and die, often just as they start to produce. Cucumbers and muskmelons are hit hardest and can be killed outright; squash and pumpkins are more tolerant. A few infected plants early can cost most of the crop.
🔬 What causes it
Bacterial wilt is caused by the bacterium Erwinia tracheiphila, which overwinters inside striped and spotted cucumber beetles. The beetles introduce it as they feed, dropping infected frass into the fresh wounds, and the bacteria then spread through the plant water-conducting tissue. Symptoms appear one to three weeks after the beetles feed, so the damage trails the insects.
🛡️ Prevent it
Since the disease rides on cucumber beetles, controlling them is the only real prevention: cover young plants with floating row cover until flowering, then remove it for pollination, and scout and manage beetles aggressively early in the season when plants are small and most attractive. Choose tolerant cucurbits, such as most squash, and resistant cucumber varieties where available.
🧯 If it is already here
There is no cure once a plant is infected, so remove and destroy wilting plants promptly, by burning where allowed or burying, and never compost them, so they do not feed more beetles. Sprays do not help an infected plant. All the leverage is in keeping beetles off healthy plants from the start.
💡 Good to know
The stringy white ooze from a cut stem is the classic confirmation of bacterial wilt and separates it from Fusarium or simple drought wilt. Because the pathogen lives in the beetles rather than the soil, the disease follows the insects, which is why early, thorough cucumber beetle control is the entire game.
🌱 Plants it affects
121 plants in the library can be affected by this problem
Annual Vinca
Celebrity Tomato
Cherokee Purple Tomato
Cinderella Pumpkin
Kabocha Squash
Norland Potato
Purple TomatilloFor educational and informational purposes only. Disease management advice is general guidance drawn from university cooperative extension sources; always identify a problem positively and read and follow the label on any product before use, especially around food crops, children, and pets.