A pest is an organism that has characteristics that are regarded by humans as injurious or unwanted, usually because it causes damage to agricultural practices. The concept of a pest is based on human perceptions. It is possible for an organism to be domestic and beneficial in one environment, and a pest in another.
Some of the pests found in Great Basin National Park are part of the natural ecosystem and regularly become more apparent when the ecosystem is stressed (like during drought). Others are non-native. The following insects and funguses have been found in the park: