Aphids

Aphids are small sap-sucking insects and members of the superfamily Aphidoidea. Common names include greenfly and blackfly, although individuals within a species can vary widely in color. The group includes about 5,000 species, with several hundred that are serious pests for agriculture and forestry as well as an annoyance for gardeners. They vary in size from 1 to 10 mm.

Description

Aphids are soft-bodied insects with a pair of cornicles (siphunculi) projecting from the posterior of their abdomen. They have long, slender mouthparts called stylets, which they use to pierce plant tissues and suck out the sap. Aphids are often found in large groups on the undersides of leaves, where they feed on plant sap.

Life Cycle

Aphids have complex life cycles, often involving both sexual and asexual reproduction. Many species can reproduce asexually through a process called parthenogenesis, where females give birth to live young without mating. This allows for rapid population growth. In some species, sexual reproduction occurs in the autumn, producing eggs that overwinter and hatch in the spring.

Ecology

Aphids are found worldwide, but they are most common in temperate zones. They feed on a wide variety of plants, including many important agricultural crops. Aphids are known to transmit plant viruses, which can cause significant damage to crops. They also excrete a sticky substance called honeydew, which can lead to the growth of sooty mold on plants.

Natural Enemies

Aphids have many natural enemies, including ladybugs, lacewings, and parasitic wasps. These predators and parasitoids can help control aphid populations in natural and agricultural ecosystems.

Management

Managing aphid populations often involves a combination of cultural, biological, and chemical methods. Cultural methods include practices such as crop rotation and the use of resistant plant varieties. Biological control involves the use of natural enemies to reduce aphid populations. Chemical control includes the use of insecticides, although this can lead to resistance and negative impacts on non-target organisms.

Related Pages

• Insecta
• Hemiptera
• Parthenogenesis
• Honeydew (secretion)
• Ladybug
• Lacewing
• Parasitic wasp