Light sandy soils may require mid-season fertilization, especially after long periods of rain. Apply three to four inches from the stems and water the fertilizer into the soil. Common Tomato Insect Pests Flea beetles make large numbers of small feeding holes in the leaves. This may seriously weaken transplants but is less damaging to larger plants. Lightweight floating row covers make good insect barriers which can be removed after plants reach the six leaf stage.
Cutworms can be a serious problem for transplants.
Barriers several inches high can be made by wrapping paper, aluminum foil, thin cardboard or similar materials around the base of transplant stems. Tomato hornworm caterpillars may consume large quantities of foliage and green fruit. Hand picking and destruction of the caterpillars, and tillage after harvest to destroy soil-borne pupae are effective controls. Aphids are small soft-bodied, often greenish, insects which feed by sucking on the undersides of leaves and the tender terminal growth. Their feeding can cause curling of the foliage.