Most Common Rex Begonia Plant Pests:
Identification and Treatment Guide

Rex begonias are beautiful and popular plants known for their stunning foliage and vibrant colors. However, like any other plant, rex begonias are susceptible to various pests that can cause damage to their leaves and overall health. In this article, we will discuss the most common rex begonia plant pests, how to identify them, and effective treatment methods.

1. Spider Mites

Spider mites are tiny pests that belong to the arachnid family. They are named so because of their webbing behavior, which is similar to spiders. These pests feed on the sap of rex begonia leaves, causing yellowing, stippling, and eventual leaf drop.

Identification:

• Fine webbing visible on the undersides of leaves.
• Yellow or white speckling on the upper surface of leaves.
• Leaves may appear dull and discolored.
• Small brown or black dots (fecal matter) on leaves.

Treatment:

1. Isolate affected plants to prevent the spread of spider mites.
2. Remove heavily infested leaves and dispose of them properly.
3. Regularly wash the remaining leaves with a gentle stream of water to dislodge mites.
4. Apply insecticidal soap or neem oil spray to kill remaining mites.
5. Repeat treatments every 7-10 days until all signs of infestation have disappeared.

2. Mealybugs

Mealybugs are small, soft-bodied insects that feed on rex begonia plants by sucking sap from the leaves and stems. They are covered in a white, cotton-like substance, which makes them easily noticeable.

Identification:

• White, cottony clusters on the undersides of leaves and along stems.
• Sticky residue on leaves caused by honeydew excreted by mealybugs.
• Stunted growth and yellowing of leaves.
• Ants may be attracted to the honeydew.

Treatment:

1. Isolate infested plants to prevent the spread of mealybugs.
2. Remove mealybugs manually using a cotton swab dipped in rubbing alcohol or soapy water.
3. Prune heavily infested parts of the plant and dispose of them properly.
4. Apply insecticidal soap or neem oil spray to kill any remaining mealybugs.
5. Repeat treatments every 7-10 days until there are no signs of infestation.

3. Aphids

Aphids are small, soft-bodied insects that come in various colors, including green, black, brown, and yellow. They feed on the sap of rex begonia plants, causing distorted growth, yellowing leaves, and the production of sticky honeydew.

Identification:

• Clusters of small insects on new growth, undersides of leaves, and stems.
• Curling or distortion of leaves.
• Sticky residue on leaves caused by honeydew excreted by aphids.
• Ants may be attracted to the honeydew.

Treatment:

1. Isolate affected plants to prevent the spread of aphids.
2. Spray affected areas with a strong stream of water to dislodge aphids.
3. Introduce beneficial insects like ladybugs or lacewings to control aphid populations naturally.
4. Apply insecticidal soap or neem oil spray to kill remaining aphids.
5. Repeat treatments every 7-10 days until all signs of infestation have disappeared.

4. Scale Insects

Scale insects are small, immobile pests that attach themselves to the stems and leaves of rex begonias. They have a protective shell-like covering that makes them hard to detect and remove.

Identification:

• Small, round bumps resembling scales on stems and leaves.
• Sticky residue on leaves caused by honeydew excreted by scales.
• Yellowing or wilting of leaves.
• Ants may be attracted to the honeydew.

Treatment:

1. Isolate infested plants to prevent the spread of scales.
2. Use a cotton swab dipped in rubbing alcohol to remove and kill individual scale insects.
3. Prune heavily infested parts of the plant and dispose of them properly.
4. Apply insecticidal soap or neem oil spray to control remaining scales.
5. Repeat treatments every 7-10 days until there are no signs of infestation.

5. Fungus Gnats

Fungus gnats are tiny flies that infest the soil of rex begonia plants. Although they do not directly damage the leaves, their larvae feed on the roots, causing stunted growth and yellowing.

Identification:

• Small, black flies hovering around the plants.
• Presence of larvae in the soil (tiny white worms with black heads).
• Yellowing and wilting of foliage.

Treatment:

1. Allow the soil to dry between waterings to discourage fungus gnat larvae.
2. Use sticky traps to catch adult fungus gnats and reduce their population.
3. Apply beneficial nematodes to the soil to control larvae.
4. Avoid overwatering and ensure proper drainage to discourage fungus gnat breeding.
5. If infestation persists, use Bacillus thuringiensis var. israelensis (BTI) products specifically designed for fungus gnat control.

By being vigilant and regularly inspecting your rex begonia plants, you can catch these common pests early and prevent severe damage. Remember to always follow the recommended treatment methods and consult with a local garden center or professional if you encounter persistent pest problems. With proper care and attention, your rex begonias will thrive, bringing beauty and joy to your indoor or outdoor garden.