Aphididae

Latreille, 1802

Aphids

Subfamily Guides

is a very large of sap-sucking insects in the order Hemiptera, containing several thousand described . Members are soft-bodied, pear-shaped insects commonly known as aphids. The family includes the majority of plant virus among insects, with approximately 200 known vector species. Many species are significant agricultural pests, causing direct damage through feeding and indirect damage through virus transmission.

Illinoia rubicola by no rights reserved, uploaded by Jesse Rorabaugh. Used under a CC0 license.

Capitophorus by no rights reserved, uploaded by Jesse Rorabaugh. Used under a CC0 license.

Brachycaudus helichrysi by (c) Susan Marley, some rights reserved (CC BY), uploaded by Susan Marley. Used under a CC-BY license.

Pronunciation

How to pronounce Aphididae: /əˈfɪdɪˌdiː/

These audio files are automatically generated. While they are not always 100% accurate, they are a good starting point.

Identification

Distinguished from other Hemiptera by the combination of soft pear-shaped body, cornicles on the , and . The presence of cornicles separates from other aphidoid . Within Hemiptera, aphids differ from scale insects (Coccoidea) by their mobile nature and distinct body segmentation, and from whiteflies (Aleyrodidae) by body shape and wing venation when winged.

Images

Appearance

Soft-bodied, pear-shaped insects ranging from 1–2 mm in length. Most possess a pair of abdominal tubes called cornicles that produce fatty when attacked. Winged forms () have forewings with four to six attached to a major vein-like structure ending in a stigma; hindwings bear a that engages the forewing during . All have small , long segmented , and a relatively long segmented rostrum for piercing-sucking feeding. Coloration varies: commonly green, but also red, brown, or black.

Habitat

Found on virtually all types of vascular plants including trees, shrubs, herbaceous plants, and agricultural crops. Colonies form on leaves, stems, and sometimes roots. Abundant in spring and autumn on deciduous trees when transport in phloem is highest; decline during summer on mature leaves that export mainly sugars.

Distribution

distribution with on every continent except Antarctica. Native to all major biogeographic regions; some species have achieved worldwide distribution through human-mediated transport on nursery stock and imported plants.

Seasonality

Activity patterns vary by strategy. In temperate regions, parthenogenetic occurs throughout the growing season with peak in spring and autumn; and production occurs in autumn. Some pest overwinter as nymphs or rather than eggs, enabling earlier spring population establishment.

Diet

Phloem sap from vascular plants. To obtain sufficient nitrogen from this -rich, protein-poor resource, aphids ingest large volumes of sap and excrete excess carbohydrates as honeydew.

Host Associations

Virtually all vascular plant families - primary -level generalization; specific ranges vary enormously among from highly specialized to extremely

Life Cycle

Most exhibit cyclical : alternating between multiple parthenogenetic () and a single sexual generation that produces . Parthenogenetic females give live birth to genetically identical daughters, with embryos of the next generation already present within newborn individuals (telescoping of generations). Developmental times are extremely short, enabling rapid increase. Some pest species have lost the sexual phase and reproduce continuously by parthenogenesis.

Behavior

Form dense colonies on plants. When disturbed, individuals release from cornicles, causing colony members to disperse. Some engage in mutualistic relationships with ants, which tend aphids and consume honeydew in exchange for protection from . Winged forms disperse to new host plants when colonies become crowded or host quality declines. Move slowly and cannot jump or hop.

Ecological Role

Major herbivores in terrestrial and significant agricultural pests. Serve as prey for diverse including lady beetles, larvae, hoverfly larvae, predatory , and . Honeydew production supports and other insects, though it also promotes growth that can reduce plant . As the most important of plant virus , mediate transmission that reshapes plant dynamics.

Human Relevance

Among the most economically important insect pests worldwide. Cause direct damage through sap removal, honeydew secretion, and promotion; indirect damage through transmission of approximately 200 plant viruses. The green peach aphid (Myzus persicae) is particularly significant as a virus . Control relies heavily on , though resistance is common. Some are , including the soybean aphid (Aphis glycines) in North America.

Similar Taxa

Adelgidae (adelgids)Also in superfamily Aphidoidea but lack cornicles; often produce woolly wax secretions; primarily conifer
Phylloxeridae (phylloxerans)Also in superfamily Aphidoidea but have different wing venation, lack cornicles, and often cause galls on plants
Coccoidea (scale insects)Also sap-sucking Sternorrhyncha but typically as , often covered with waxy secretions or shells, and lack the mobile, soft-bodied form of aphids

More Details

Taxonomic controversy

Classification within Aphidoidea remains disputed. Conservative treatments recognize 24 within ; alternative classifications elevate many subfamilies to rank, creating up to 10 families within Aphidoidea.

Evolutionary history

Aphids originated in the late Cretaceous approximately 100 million years ago. The Aphidinae, comprising about half of extant described , underwent major radiation in the late Tertiary less than 10 million years ago.