Top Ten Tree Problems

Lace Bug

Lace bugs target broad-leaf evergreens such as andromeda, azalea, and rhododendron. Early detection is the key to getting rid of an infestation. Look for yellow-silver stippling on the topsides of leaves.

Mites

Mites are common in landscapes and favor warm, dry climates. Some are plant feeders and some are beneficial. Natural predators can keep the population low, but because mites are small and if they go unnoticed damage will be apparent before they are found. Treatment includes correct watering so plants are not stressed and washing off affected plants or using insecticidal soaps.

Tent Caterpillars

Caterpillars can weaken many trees and shrubs, increasing the chance of a secondary infestation. Look for silken, yellow cocoons. Western tent caterpillar feed on Coast Live Oaks. Inspection and pruning of infected limbs or spraying with control insecticides is recommended.

Borers

Borers are attracted to unhealthy trees, burrowing in and laying eggs inside the trunk. The best defense against borers is to keep your trees healthy and unstressed with proper irrigation, fertilization and pruning.

Adelgid

One of the most common pests, these insects feed on conifers and can cause the death of a tree if left untreated. They leave behind a telltale white wax and target primarily older trees.

Eucalyptus Psyllids

Several species of Eucalyptus psyllids from Australia and New Zealand have been introduced to California. They cause defoliation and a clear liquid dripping from Eucalyptus. Treatment includes injections or spraying of targeted insecticide.

Anthracnose Disease

This fungal disease affects deciduous and flowering trees and especially California Sycamores. Look for a spotting of foliage in spring and summer.

Scale

Scale insects are numerous and common on trees. They cause sticky, blackened and sooty foliage. Acacias, Palms, Podocarpus, Olive, Magnolia and Pepper trees as well as fruit trees are affected. Lady bugs, some parasitic wasps and natural predators. For infestations foliar sprays, insecticidal soaps and narrow range oils are recommended.

Weevil Insects

Weevils are commonly found on flowers and fruits. Look for notches around the edge of leaves. Treatment includes targeted timely spraying of insecticide.

Aphid Insects

Aphids are small and pearl shaped. An infestation can cause yellow discoloration and defoliation. Natural insect predators are the best control, and when necessary targeting with an insecticidal soap and spray will provide control.