Southern Potato Wireworm

• Wireworms are wiry larvae that are whitish to yellow-gray in color with a reddish-orange head. They feed primarily on potato tubers, but will also attack tomato plants, leaving ragged holes in the plant roots. The southern potato wireworm originated in South America but is now found in many regions of the United States. Symptoms of an infestation include yellowing of leaves and wilting.
  
  

Root Knot Nematodes

• Root knot nematodes are white and very small, resembling tiny pearls. They can usually only be seen under magnification and spend the majority of their time in galls that they form on the root of a tomato plant. These galls are typically an inch in diameter, but may be smaller. The galls disrupt the flow of nutrients and water to the tomato plant, causing the plant to yellow and become weakened.
  
  

Cutworms

• Cutworms are the larvae of about 15 species of moths that may feed on tomato plants. These belong to the family Noctuidae and feed at night, remaining below the surface of the soil during the day. Cutworms are typically about 1 to 2 inches long and are gray, green or brown in color, marked with spots or striped. A few species live in the soil and feed on tomato plant roots and underground stems. Most spend winter months in the caterpillar stage and feed through the spring before going into the pupa stage in the summer. You may find them during the day curled up near damaged plants or hiding under dead plant material on the ground.
  
  

Prevention and Control

• Eliminating weeds and tall grass in the fall can reduce populations of cutworms the following spring. Cultivating the soil thoroughly each fall and before planting in the spring will also expose any hidden larvae in the soil. Weeding can also effectively control the development of root knot nematodes. There are also chemical treatments available such as carbaryl, which is intended for cutworm control. There are few known ways to effectively control the southern potato wireworm, as there are no known natural predators. Wireworms have also developed a resistant to some insecticides. However, rotating crops by planting non-host crops like soybeans after an infested crop may be effective in reducing their populations.