Skip to main content

Aphids Identification & Eating Habits

family sitting at the table eating dinner

Aphids are tiny insects that suck on the sap in temperate regions of the world. They are well-known pests in these areas going by other names such as greenflies, blackflies, or whiteflies. They are also known colloquially as plant lice in Britain. These small bugs can do a lot of damage to crops and gardens throughout the world. Zoologists regard aphids are particularly successful much because some species are able to reproduce asexually. There are over 4,000 species of aphids of which 250 are destructive agricultural pests. They can be a serious annoyance to gardeners who may use ladybugs or other biological control mechanisms to keep populations under control.

How to Identify Aphids

The aphid ranges in size from 0.04 inches to 0.39 inches in length. They have two compound eyes. They can be found throughout the world, but are most diverse in temperate regions. By riding the wind, aphids can migrate long distances although sometimes these tiny insects are spread via human transportation of plants that are infested. Their bodies are soft and their color varies. They may be green, brown, pink, black, or even colorless. They eat via sucking mouthparts and have long, thin legs. Many aphid species have a pair of abdominal tubes that they can use to excrete a special fluid that can help them defend themselves. The fluid contains triacylglycerols and it is known as cornicle wax. The wax quickly hardens once it is excreted. There are other types of defensive liquids that can be produced by other types of aphids.

Do Aphids Have Wings?

When a host plant becomes overcrowded or the environmental conditions become less than ideal, many aphid species will begin to produce winged offspring. These offspring are then able to find other plant resources. However, winged offspring may be compromised in other respects with mouthparts or eyes that are small or missing as a result of the genetic changes.

What do Aphids Eat?

A number of species of aphids will only feed on one type of plant. Others are willing to feed on many different types of plants. They actively seek out sap from the phloem vessels of living plants. By merely puncturing the phloem vessel, the sap is forced into the aphid’s mouth due to the high pressure that it is under inside the vessel. It is possible and sometimes prudent for aphids to also eat xylem sap, though it is more diluted than the nutritious substances they can get through the phloem of a plant. Xylem sap also isn’t as easy to obtain. Aphids must actively suck at the plant in order to get the sap from the xylem. Some experts speculate that aphids will drink the dilute sap of the xylem in order to replenish their water needs.

Aphids not only suck nutritious substances out of living plants, but they are also responsible for transmitting diseases to the plants that they inhabit. In particular potatoes, sugarbeets, citrus plants, and cereals can all become host to disease as a result of aphid infestation. Viruses that are transmitted as a result of the aphid’s feeding habits can sometimes even kill the plants.