Aphids – Identification and Control

Last updated March 1, 2023

Aphids - Identify and Control — Aphids – Identify and Control

Identification

Aphids are small sap-sucking insects, about 1/8 inches (3 mm) long.
They vary in color from green, peach, brown, black, and sometimes colorless.
These garden pests have a pair of antennae on the tip of the head region and short legs.
Most species have a pair of tubes emerging from their abdomen.
Aphids have long slender sap-sucking mouthparts.
Most of them live on the undersides of the leaves or the top part of the plant’s stems.

Lifecycle

Aphids have incredible reproductive capabilities. In spring, females hatch from overwintering eggs and soon give birth to nymphs.

Aphids can reproduce so quickly because female aphids give birth to live young that are already pregnant. In just a couple of weeks, the young reach maturity and gives birth to other pregnant nymphs.

Most aphids do not even have to mate to reproduce, and they produce live nymphs rather than eggs. This process is repeated several times. A short cycle of reproduction results in exponential population growth. There are many overlapping generations per year.

These insects are wingless. However, as the population increases, some females develop wings and fly out to colonize other plants. At the end of the summer, males and females develop, mate and lay overwintering eggs. These will be the following years’ generation.

Damage They Cause

Aphids feed in clusters on new plant growth or the undersides of leaves, resulting in the stem’s curling, distorting, or discoloring. Well-established plants can tolerate some damage, but young growth may be stunted.

Aphids excrete a sticky, glossy liquid called honeydew that discolors leaves and causes an unsightly black sooty mold to grow.

In small numbers, aphids do minor damage. Still, they can reproduce rapidly and quickly become a more severe problem.

Plants They Attack

As there are a lot of species of aphids, each species can attack different types of plants. However, garden plants most susceptible to their attack are:

Apple Trees
Beets
Beans
Cucumbers
Lettuce
Melons
Mint
Nasturtium
Pumpkins
Peppers
Potatoes
Roses
Squash
Tomatoes

Live Biological Control

A lot of predatory insects will feed on aphids. Attract beneficial insects to control them:

Aphidius Wasp
Assassin Bugs
Big-eyed Bugs
Damsel Bugs
Hoverfly Larvae
Ladybugs
Lacewings
Minute Pirate Bugs
Parasitic Wasps
Praying Mantis.
Spiders

Organic Control

Soap and Water
Neem Oil
Garlic Extract
Horticultural Oil
Insecticidal Soap

Preventive actions

Remove. Keep monitoring your plants regularly and remove infested plant growths.
Dislodge. Use a fine jet stream of water to blast the aphids off.
Trap. Plant various plants that will trap aphids, preventing the important crops from being damaged.
Select plant varieties for your garden that can withstand pest damage.
Cover susceptible plants with lightweight floating row cover to block the access. Ensure to remove the cover when your plants begin to flower.

More About Aphids

If you see aphid cream in color and motionless, do not remove it. It means that it was infected by an aphidius wasp. The wasp will hatch from this aphid and will further control the aphid population.

Sometimes you will see ants walking among aphids. Aphids secrete a sugar-rich fluid called honeydew which the ants harvest to feed on. Ants also protect aphids from predators by either driving away enemies or killing them.

The relationship between aphids and ants is an example of symbiosis, where two different species live together in a way that benefits both parties. This is called mutualism because the two species depend on each other for survival.

Also, watch this fun video about aphids, presented by TED-Ed.