Endangered Arthropod - Mechanisms of Arthropod Endangerment

Mechanisms of Arthropod Endangerment

There are several pathways of endangerment for arthropods; however, most of them stem from the pressures of an expanding human population and resulting actions humans take to produce food, housing, transportation and recreation. Probably the greatest hazard to arthropod survival is agriculture, due to the ever increasing demand of the human population to feed its expanding numbers. Agriculture typically results in a monoculture that cannot support the biodiversity nurtured by the predecessor natural environment. Normally arthropods represent the largest number of species that are displaced by such farming. In tropical regions the major threat is slash-and-burn agricultural techniques pursued by indigenous peoples in their sometimes only available method of subsistence.

Pesticide use is also a major threat to arthropod species survival. Pesticides may have an intended effect of killing specified insects in a farming environment; however, considerable pesticide applications kill unintended species by the lack of specificity of most chemical formulations; moreover, much of the insect mortality arises from pesticide runoff entering surface waters or from transporting toxic chemicals to downgradient environments.

Habitat fragmentation has special methods of endangerment beyond the amount of land consumed by the fragmenting agent. As an example, consider the construction of a highway, whose width is an effective barrier to arthropod migration. Many arthropods never migrate more than about 200 feet from their place of birth, so a freeway or dual carriageway effectively fragments many arthropod colonies such that they cannot interact. Studies have shown the greater vulnerability to extinction where habitats are fragmented.