Tomato plants are susceptible to pest damage. The leaves and fruit of the plant attract a variety of bugs, and these insects are capable of destroying your garden tomato crop. Some pests eat holes in the leaves and bore into the fruit, while others suck the juice from the leaves and stems, weakening them. Still others feed on the roots of the tomato plant.
Aphids, Whitefly and Stink Bug
This group of pests sucks the sap from your tomato plants. Aphids gather in large groups on the stems and leaves and sink fang-like protrusions into the plant. Aphids secrete a sticky substance onto the plant that renders the plant susceptible to mildews.
A swarm of whitefly may land on your tomato plants and drink the juices from stems and leaves. If you see the leaves on your tomato plant turning yellow and the stems drooping, shake the plant. You may see something that looks like a whispy white cloud rise up. That is a swarm of whitefly.
The stinkbug isn't as social as the other sap suckers, but you are likely to find more than one or two taking up residence in your tomato plants. These bugs are brown, black or green, are shield-shaped and give off a disagreeable odor when handled. If the leaves are wilting and the underside of your fruit exhibit hard white spots, look for stinkbugs on your plant.
Cabbage Looper, Fruitworm and Leafminer
The cabbage looper is a small green caterpillar with white stripes. It chews holes in the leaves, leaving only the veins. The fruit becomes vulnerable to sun scald due to the loss of foliage.
The fruit worm is moth larvae laid on the outer edges of the leaves of the tomato plant, usually near to tender green fruit. The fruit worm then burrows into the young tomato, leaving it damaged.
The leaf miner is a maggot that leaves winding white paths in its wake. These curving lines are evidence of the leaf miner's ability to tunnel into the leaf itself and feast on the soft tissue.
These fat worms hang around the base of the plant, chewing on the lower, tender stems. By day, they burrow into the ground, and in the dank and darkness, chew on the uppermost roots. The cutworm enjoys the lower seedling stems, from which new fruit-bearing branches of the plant grow, causing the plant to be thin and weak. The damage to the roots leaves the plant susceptible to rotting.