(Not what you're seeing? Check hornworms.)
While the bug (shown above) looks like a worm, it is actually the immature larva of the Colorado Potato Beetle. The larva come in a variety of different colors (red, yellow, orange). I suspect that the color changes based on the age/stage of the larva.
NOTE: These little insects have a great appetite and can inflict massive damage on your tomato plant's leaves and stems.
Named for their taste for potato plants, potato beetle larva are also quite happy to make a tasty meal of your tomato plants (or other plants of the same family).
As shown above, Colorado Potato Beatle Larva tend to have rows of black dots along their sides.
Adult version shown below
The adult version of the Colorado Potato Beetle (also known as potato bugs) is a yellow beetle with black stripes. The adults will also dine your tomato plants.
Note: If left to themselves, they'll reproduce and lay eggs that will exponentially increase the bug infestation.
You'll find their orange eggs in rows on the undersides of leaves. Once the eggs mature, you'll have another hatch of Potato Beetle larva. The life cycle of this pest tends to complete in a month. Depending upon the length of your gardening season, you can have multiple generations in any one gardening season.
NOTE: These bugs will not only dine on your tomato and potato plants, but also any others in the same family, such as peppers, eggplants, etc.
Organic Potato Beetle Control:
Pick the bugs by hand. (Note: you'll need to be dilligent and enthusiastic in your effort.) I place the larva / bugs in a container with water mixed with liquid soap.
If you find any leaves with eggs, be sure to destroy and dispose of them.
It's also thought that a very thick layer of mulch around the base of the plants might help thwart potato beetles in their reproductive efforts.
Spray once a week, until the potato beetle infestation is gone. Consult your local garden authority, but they'll most likely recommend a pesticide such as SEVIN, or diazinon.
- Organic insect control ideas
- Companion Planting for Insect Control
- Incorrect Soil pH Could affect plant health. How to Test Soil pH
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Note: the advice and information contained herein is based upon our experience and study.
As with any advice, please apply at your own discretion.