Eriosoma

Eriosoma

Classification

Pronunciation

How to pronounce Eriosoma: //ˌɛr.i.oʊˈsoʊ.mə//

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

Images

Eriosoma strobi by the Smithsonian. Used under a CC0 license.
Eriosoma querci by the Smithsonian. Used under a CC0 license.
Eriosoma pyricola by the Smithsonian. Used under a CC0 license.
Eriosoma strobi by the Smithsonian. Used under a CC0 license.
Eriosoma rosetti by the Smithsonian. Used under a CC0 license.
Eriosoma pyri by the Smithsonian. Used under a CC0 license.

Summary

Eriosoma lanigerum, commonly known as the woolly apple aphid, is a sap-sucking aphid primarily affecting apple trees, causing significant damage through gall formation and honeydew secretion. It has a complex life cycle with predominantly asexual reproduction and is disseminated through multiple generations per year.

Physical Characteristics

Small to medium-sized aphids, up to 2mm long, elliptical shape, reddish brown to purple color typically obscured by white cotton-like secretion from specialized glands. Newly moulted individuals lack the wax coating. Sooty-brown antennae with six segments; tibias vary from dark brown to yellowish. Nymphs are salmon pink with dark eyes and circular cornicles; can appear dark green to almost black when hibernating.

Identification Tips

The presence of a woolly substance distinguishes Eriosoma lanigerum from other aphids on apple trees. When crushed, they leave a blood red stain.

Habitat

Eriosoma lanigerum typically inhabits apple trees and other hardwoods, with a preference for sited infestations at the axils of leaves on terminal shoots.

Distribution

Originally native to North America, now found worldwide in regions where apples are grown; first recorded in Great Britain in 1787.

Diet

Sucks sap from host plants, predominantly apple and various other hardwood species.

Life Cycle

Undergoes a life cycle with up to 8-12 generations per year, includes both sexual and asexual reproduction. In cooler climates, survives winter as nymphs or eggs.

Reproduction

Primarily asexual reproduction through parthenogenesis, with occasional sexual reproduction resulting in egg laying on Ulmus americana.

Predators

Predators include the bug Anthocoris nemoralis, ladybirds, hoverfly larvae, lacewings, and earwigs (Forficula auricularia).

Ecosystem Role

Key herbivore of apple and related species in ecosystems, influencing plant health and nutrient cycling.

Economic Impact

Causes galls on apple trees, damaging roots and reducing tree growth; can lead to lower fruit quality due to honeydew excretion.

Collecting Methods

  • Direct collection from host plants
  • Tree banding
  • Visual inspection for galls and aphids

Preservation Methods

  • Dried specimens in insect display cases
  • Alcohol preservation for genetic studies

Evolution

Part of the Eriosomatinae subfamily, showing adaptations for living in various host plants and environments.

Misconceptions

Some misidentifications exist, with specimens collected from elms that may actually belong to different species than E. lanigerum.

Tags

  • Eriosoma
  • woolly apple aphid
  • Aphidoidea
  • sap-sucker
  • plant pest