Other arthropods such as spiders and certain mites also are beneficial. There are two main types of beneficial arthropods, predators and parasitoids . Predators , such as ladybugs and spiders, will attack several different kinds of insect, and will consume several prey throughout their life cycle. The egg hatches and the immature parasitoid feeds on the victim, called a host , eventually killing it. Each developing parasitoid kills only one host in the course of its life cycle, but parasitoids are more specific in the insects they attack than predators.
Insects also suffer from diseases.
Insect diseases, or entomopathogens, are micro-organisms that attack insects, and include bacteria, fungi, viruses, and nematodes. With few exceptions, the diseases that attack arthropods do not afflict warm-blooded animals. Sometimes insects and plant disease agents are used to control weeds. Controlling Pests Biologically Biological control is an approach to reducing populations of harmful organisms with natural enemies. Organisms introduced from other parts of the world are called exotic or nonindigenous , as opposed to native or indigenous organisms.