Summer in San Diego is prime time for outdoor enjoyment—but it’s also peak season for many plant-damaging pests. Whether you’re growing a backyard vegetable garden or tending to your landscape, these pests can quickly wreak havoc on your greenery. Knowing what to watch for can help protect your plants and avoid costly damage. Here are some of the most common plant pests in San Diego during the summer months, how to identify them, and what to do about them.
Common Plant Pests in San Diego
1. Aphids
These tiny, pear-shaped pests are soft-bodied and come in green, black, or gray varieties. Aphids feed on plant sap and reproduce rapidly, often forming large colonies on new growth.
- Damage: Curling or yellowing leaves, stunted growth, and sticky honeydew that attracts ants and sooty mold.
- Common Hosts: Roses, tomatoes, citrus, and milkweed.
2. Caterpillars (Including Tomato Hornworms and Cabbage Loopers)
Caterpillars can be highly destructive, chewing through leaves, stems, and fruit overnight.
- Damage: Large, irregular holes in leaves, stripped foliage, and visible droppings (frass).
- Common Hosts: Tomatoes, peppers, broccoli, citrus, and other leafy greens.
3. Whiteflies
Whiteflies are small, moth-like insects that congregate on the undersides of leaves. When disturbed, they scatter in a cloud-like burst.
- Damage: Sap feeding causes leaf yellowing and wilting. Like aphids, they excrete honeydew, leading to mold growth.
- Common Hosts: Hibiscus, cucumbers, squash, tomatoes, and ornamental plants.
4. Spider Mites
Spider mites are tiny arachnids that thrive in hot, dry weather—making San Diego summers ideal for outbreaks.
- Damage: Speckled yellow or bronze leaves, fine webbing on the undersides, and leaf drop.
- Common Hosts: Citrus, tomatoes, strawberries, beans, and ornamentals.
5. Leafhoppers
Leafhoppers are wedge-shaped insects that jump from plant to plant, feeding on sap and spreading diseases.
- Damage: Yellow or white spots on leaves, stunted growth, and curling foliage.
- Common Hosts: Grapes, tomatoes, beans, and many shrubs.
6. Grasshoppers
Grasshoppers can be a bigger problem in drier inland areas but still show up near coastal landscapes.
- Damage: Ragged-edged leaves, chewed flowers, and exposed stems.
- Common Hosts: Lettuce, corn, flowers, and various grasses.
7. Mealybugs
These soft-bodied insects are covered in a white, cottony substance and love to hide in plant crevices.
- Damage: Sticky residue, yellowing leaves, stunted growth.
- Common Hosts: Succulents, citrus, tropical plants, and houseplants.
8. Scale Insects
Scale insects look like small bumps on plant stems and leaves. They’re often overlooked until damage is noticeable.
- Damage: Yellowing foliage, sticky honeydew, and a weakened plant.
- Common Hosts: Citrus, ficus, ornamental shrubs, and succulents.
9. Argentine Ants
While they don’t feed on plants directly, Argentine ants protect and farm sap-feeding pests like aphids and whiteflies in exchange for honeydew. This symbiotic relationship increases plant damage and pest populations.
- Damage: Encourage other pest infestations, reduce effectiveness of natural predators.
- Common Hosts: Any plant infested with sap-feeders.
Protecting Your Plants from Summer Pests
- Inspect plants regularly for pests and damage.
- Use yellow sticky traps to catch flying insects.
- Apply horticultural oils or insecticidal soaps to control aphids, whiteflies, and mites.
- Attract beneficial insects like ladybugs and lacewings to help control pest populations naturally.
- Call a professional pest control company if an infestation becomes severe or widespread.
Get Professional Plant Pest Control in San Diego
If you’re seeing signs of pest damage in your yard or garden, don’t wait. A certified pest control expert can identify the culprit and provide eco-friendly, effective treatment options tailored to your landscape.
Looking for trusted pest control near you for plant pests? Our San Diego pest control specialists are ready to help you protect your plants and restore your peace of mind.
