Insect pests frequently have natural enemies that are beneficial to the landscape. These beneficial insects often exist in the landscape naturally, but they also can be introduced. One common example of a beneficial predator is the lady beetle. Both the larvae and adult lady beetles eat aphids and other soft-bodied insects. Other predators include lacewings, spined soldier bugs, flower flies, and spiders.
Parasites live on and often kill another organism, called the host.
Some parasitic wasps use caterpillars, whiteflies, aphids, and soft scales as hosts. Bt contains a protein that is poisonous to specific insects, yet harmless to other organisms. Bt can be sprayed on plants. When the sensitive insect pest feeds on the sprayed leaves, it will ingest the protein and be killed. Chemicals Conventional chemicals are used only as a last resort in an IPM program, but sometimes are the most effective means of control.