How to Tell Aphids from Spider Mites

Schyler Thibodeaux, LSU AgCenter, Assistant Agriculture and Natural Resources Agent

Many plant problems are caused by pests that are so small that they are difficult to see with the naked eye. Two of the most confused plant pests are aphids and spider mites. While both are tiny and often found in large numbers, they differ in appearance, behavior and the type of damage they cause. Learning to recognize these differences can help gardeners and growers diagnose problems accurately and choose effective management strategies.

Aphids

Aphids are soft-bodied insects with a characteristic pear-shaped body. Just as all other insects do, they have six legs. They come in a variety of forms (winged or wingless) and colors (white, brown, black, pink, yellow, red and gray).

Aphids feed by sucking sap from leaves, stems and buds, especially tender new growth. As they feed, aphids excrete a sticky substance called honeydew, which can lead to sooty mold on plant surfaces.

Common aphid damage symptoms include:

• Stunted or distorted plant growth

• Yellowing, wilting or curling leaves

• Sticky honeydew on leaves and stems

• Black sooty mold developing on honeydew-covered surfaces

In addition to direct feeding damage, aphids can also transmit plant diseases.

Spider Mites

Spider mites are not insects, but arachnids, making them relatives of spiders and ticks. They have an oval-shaped body and eight legs, which helps distinguish them from aphids. Spider mites are typically red-brown, but may also appear yellow, green or orange. Spider mites never have wings.

One of the most noticeable signs of spider mite infestation is the presence of fine webbing on leaves and stems. Webbing usually begins on the undersides of leaves and can spread over the entire plant in severe infestations.

Spider mites feed by piercing individual plant cells and sucking out their contents.

Common spider mite damage symptoms include:

• Tiny yellow or white speckles (stippling) on leaves

• Bronzed or scorched-looking foliage

• Leaf drop in severe infestations

• Fine webbing on leaves and stems

Correctly identifying these troublesome pests is the first step toward effective pest management. Because aphids and spider mites differ in biology and behavior, successful control depends on proper diagnosis. When managing pests, consider using multiple tactics in harmony. Integrated pest management (IPM) emphasizes prevention, regular monitoring and the use of the least disruptive control options to manage pest populations effectively and sustainably.

Integrated Pest Management (IPM) for Aphids and Spider Mites

Monitoring and Early Detection

• Inspect plants regularly, especially undersides of leaves and new growth.

• Look for symptoms such as curling leaves, stippling, honeydew or webbing.

• Use a hand lens or gently tap foliage over white paper to detect small pests.

Cultural Controls

• Maintain proper plant health through adequate watering, fertilization and spacing. Insects are attracted to stress just as easily as they cause stress.

• Remove heavily infested plant parts.

Biological Control

• Avoid unnecessary broadspectrum insecticides that can reduce beneficial insect populations and worsen pest outbreaks.

• Many beneficial insects naturally suppress aphids, including lady beetles, lacewings and spider mites, including predatory mites.

• Predatory mites are natural enemies of spider mites.

Mechanical and Physical Controls

• Strong streams of water can dislodge aphids and spider mites from plants.

• Prune and destroy heavily infested plant tissue to reduce pest numbers.

Chemical Control

• Use pesticides only when monitoring indicates populations exceed acceptable levels.

• Insecticidal soaps or horticultural oils are often effective against aphids and spider mites when applied thoroughly.

• Follow label directions carefully and ensure products are labeled for the intended plant and pest.

• Rotate products when repeated treatments are needed to reduce resistance development.

Summary

Although aphids and spider mites are similar in size, careful observation can reveal important differences. Counting legs, looking for wings or webbing, and noting plant damage symptoms are all useful tools for correct identification. Proper identification is the first step toward effective pest management. Combining monitoring, cultural practices, biological control and targeted treatments provides the most effective and sustainable pest management.

Spider mite feeding sites and leaf speckling. Photo by Heather Kirk-Ballard

P4040
3/25/26
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