Young tomato plants are susceptible to flea beetles and cutworms, but once past the early growth stage, tomatoes are not as vulnerable to insect damage. Here are some of the most common insect pests and control measures for each. Aphids Aphids come in a variety of colors. Black aphids infest green beans late in the summer. Green aphids infest cabbage family plants and are especially annoying on broccoli and cabbage, where they hide within the head.
Aphids weaken plants by sucking juices from their tissues and can spread disease.
Resident ladybugs and other predators can substantially reduce aphid populations. Take care to protect and encourage these predators. Also limit damage by removing aphids with a stream of water from a garden hose or by smashing them. Insecticidal soap, malathion, and diazinon will control aphids. Cabbage maggot These underground larvae inflict damage on cabbage family varieties and radishes.