Aphidoidea

Pronunciation

How to pronounce Aphidoidea: /ˌæfɪˈdɔɪdiə/

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Summary

Aphidoidea, also known as aphids, encompasses small, diverse sap-sucking insects. They have complex life cycles and reproductive strategies, significant ecological roles as pests of plants, and unique mutualistic interactions with ants.

Physical Characteristics

Aphids have soft bodies, which may be green, black, brown, pink, or almost colorless. They possess a pair of compound eyes and antennae with two short, broad basal segments and up to four slender terminal segments. Their mouthparts are modified into sucking stylets, enclosed in a rostrum. Most aphids have a pair of cornicles on their fifth abdominal segment for excreting defensive fluids.

Identification Tips

Common names include greenfly and blackfly. Typically small in size, they may vary in color across different species. The presence of winged forms during certain times of the year is characteristic for many species.

Habitat

Aphids can be found worldwide, predominantly in temperate regions. They inhabit various plant species, often colonizing agricultural crops and ornamental plants.

Distribution

Aphids are distributed worldwide and are most common in temperate zones. Their species diversity is lower in tropical regions, and some species have been spread by human transportation of infested plant materials, making them nearly cosmopolitan.

Diet

Aphids primarily feed on the sap of phloem vessels in plants. Some species are monophagous, feeding on a single plant species, while others are generalists and can exploit various plant groups. They also ingest xylem sap under certain circumstances.

Life Cycle

The aphid life cycle typically involves flightless females giving live birth to female nymphs without male involvement (parthenogenesis). Many species exhibit telescoping generations, and they can produce multiple generations rapidly. Sexual reproduction occurs in autumn, usually leading to the production of eggs that overwinter.

Reproduction

Aphids can reproduce both sexually and asexually, depending on environmental conditions. They typically produce live young through parthenogenesis. In autumn, sexual reproduction occurs, resulting in the laying of eggs that survive the winter.

Predators

Natural enemies of aphids include predatory ladybugs, hoverfly larvae, parasitic wasps, lacewing larvae, crab spiders, and entomopathogenic fungi. Birds also consume high numbers of aphids.

Ecosystem Role

Aphids play a crucial role in the food web, serving as prey for various predators. They also engage in mutualistic relationships with ants, which protect them and farm them for honeydew.

Economic Impact

Aphids are significant agricultural pests, with around 400 species identified as serious threats to food and fiber crops. They weaken plants, transmit plant viruses, and can lead to reduced yields.

Cultural Significance

Aphids have been noted in historical records as pests, with mentions of their impact on gardens and agriculture throughout history. They are also involved in traditional medicine indirectly through the plants they infest.

Health Concerns

Aphids can trigger allergic inhalant reactions in sensitive individuals during large outbreaks.

Collecting Methods

• Yellow-pan traps
• Moericke traps
• Strong water jets

Preservation Methods

• Ethanol
• Drying

Evolution

Aphids and their relatives likely evolved from a common ancestor about 280 million years ago, displaying adaptations that have allowed them to exploit various ecological niches, especially in association with flowering plants during the diversification of angiosperms.

Similar Taxa

• Adelgidae
• Phylloxeridae

Misconceptions

It was once believed that aphids produced honeydew from their cornicles, while in reality, honeydew is excreted from the anus, and cornicles are more involved in the production of defensive chemicals.

Tags

• Aphids
• Insects
• Pests
• Agriculture
• Entomology