Their young usually feed inside the insect host, killing it and emerging in the adult parasite form. Follow this link to see some common predators and parasites of insect pests. Life cycles of some insects useful in biological control. Another important group is hunting wasps . These wasps capture and paralyze insects and take them to their nests, which may be dug in the ground, cut into wood or are constructed of wood or paper.
Insects can be very important in controlling plant pests.
For example, lady beetles may eat several hundred aphids during the two or three weeks they are growing-and many more after they become an adult beetle. Parasitic wasps may lay dozens of eggs, each developing into an insect that kills a pest, and a new generation may occur every three weeks, allowing them to become very abundant in a short period. Often, the benefit of these useful insects is not realized until their activity is disrupted by use of insecticides, which sometimes has more severe effects on the beneficial insects than it does on the pests. The use of predators and parasites of insect pests is known as biological control. Although some insects damage desirable plants, others feed on plants we consider to be weeds.