As your tomatoes ripen, you may notice something is amiss. The first hint may be yellowing of leaves, missing leaves or half eaten fruit. You may see small insects attacking your tomato plant before your very eyes. How to prevent or eradicate pests depends on their type.
Handpick horn worms off the tomato plants. This is the safest method of removing these large green caterpillars, which are easy to identify by the green "horns" on their backs. By the time you see horn worms, it is too late in the season to spray insecticide. Handpicking may take some time, but you can get the whole family involved.
Drop the horn worms in a bucket full of soapy water. This will kill them. Dispose of the water far from the garden area.
Spray a Bacillus thuringiensis solution on your plants. The horn worms eat this bacteria, stop eating your tomatoes immediately and die.
Wash aphids off your tomato plants using a garden hose. These small insects may be green, yellow or pink. They suck the sap from that tomato plant and spread disease.
Apply insecticidal soap if plain water does not solve the problem.
Wash aphids off every day. They are tenacious insects.
Remove beetles by handpicking during the day. Be careful not to squish the beetles in your hand. Some have toxic liquids that can cause blisters on your skin. The most common beetles are Blister beetles and Colorado potato beetles.
Spray plants with insecticide if handpicking is not efficient. Two types that work best are Bacillus thuringiensis "San Diego" and pyrethrum.
Monitor plants closely. If the beetles return, take action immediately, before damage occurs.
Place newspaper around tomato stems when you plant them. The paper should extend 1 inch above the soil and 2 inches below the soil. This blocks cutworms from getting to the plant.
Monitor plants weekly.
Replace newspaper as needed.
About this Author
Cate Rushton has been a freelance writer since 1999, specializing in wildlife and outdoor activities. Her published works also cover relationships, gardening and travel on various websites. Rushton holds a Bachelor of Arts in English from the University of Utah.