Aphid Ecology: Life Cycles, Polymorphism, and Population Regulation

Abstract

Aphids are plant sucking bugs which occur throughout the world. The greatest number of species are in the temperate regions, where few higher plants are free from aphids. They differ from other plant sucking bugs of the Aphidoidea in that the females of at least a few generations are parthenogenetic and viviparous. Although many species are small and inconspicuous, they frequently become abundant. As many as 2000 million per acre (0.4 ha) may live on the above-ground parts of plants, and the roots may support a further 260 million (46, 92, 117, 148). Aphids, like many other insects, are capable of migrating great distances (up to 1300 km) by means of wind (25, 48, 70). Polymorphism is characteristic of aphids. Asexual aphids of some species can either possess wings (in which case they are termed alatae), or lack wings (these morphs are called apterae). Typically there are several structurally different morphs in a species, including both sexual and asexual forms.