Invasive tree pests are out in the landscapes

Roger Boddaert

Special to the Village News

Beware of these bugs in your trees out in the garden setting, for they are invading more ornamental trees these days. The word “bug" has been around since ancient times, but as the climate and weather change, new insects are moving northward with the warming climate and attacking a wide range of ornamental trees and plants out in our gardens.

While there are new insects, diseases, and environmental threats today, the invasive bugs are gaining a foothold in the Southern California landscape, so be vigilant and observant of what is out there, and practice proper and safe horticultural management.

Gold spotted oak borer: This insect has immigrated from Central America and is invading our California native oak trees. This beetle can attack and kill mature oak trees. When oaks are attacked in massive numbers by these beetles, they set up huge colonies and are found in the cambium tissue of oaks just under the bark.

When trees go into a stress mode, their immune system starts to break down, and the tree becomes susceptible to invasive bugs of assorted types.

Oak trees in Fallbrook are one of our true native heritage trees and create the green fiber that makes our town so attractive and environmentally unique and special.

A coastal live oak, which is extremely valuable, can be valued at $300 for every year of its life. A 100-year old oak tree killed by this borer, can be conservatively worth $30,000.

The entry hole into the bark from this beetle is like a capital D, as a key indicator to its presence, and not like the traditional round circle like other beetle holes.

Keeping oaks and other trees in a healthy state is one of the key components of good stewardship.

Trees are like people and need check ups from time to time, so be a good steward and pay attention in your garden to the various bugs and diseases invading the landscape.

South American palm weevil: The South American palm weevil is attacking certain palm species in Southern California. The adult moth lays its eggs inside the top of the new fronds. When the larvae hatch, they feed on the tender new palm fronds in the center of the tree.

When these palms die from the invasion of these weevils, they can be very costly to remove. Look for the yellowing of emerging palm fronds. Large holes at the base of fallen fronds can be another indicator of the grub presence.

Do not shave the trunks of the Canary palms into a large pineapple shape. This causes stress to the tree, and has become popular with tree trimmers, who do not know the aftermath of this injustice to the palm tree.

Invasive shothole borers: One in three urban trees in Southern California is susceptible to this invasive bug. If left unchecked, this pest can cause devastating effects in our urban forest and cause huge economic damage.

Look for signs and symptoms like wet staining oozing from the trunks of the trees. Pay attention to small round holes and boring dust on the outer bark from borers.

The movement of firewood and tree trimmings infested with invasive insects is the most significant pathway for introducing the bugs from one area to another.

Fire-blight on ornamental pears: This bacterium can cause considerable damage to ornamental pear trees and can be spread by infected pruning tools from one tree to another. This fungal disease can attack other plants in the rose family like pyracantha, cotoneaster, apples, crabapple, loquat, spirea, and others.

Citrus greening: This is a devastating plant disease that is plaguing the entire citrus family. It is known as Huanglongbing or HLB, which originally entered this country from Asia. It has spread from Florida, Texas, Arizona, and some locations in California.

Symptoms of HLB are blotchy mottled leaves, stunted growth, reduced fruit size, fruit drop and potential tree death. The carrier of this disease is the citrus psyllid, which can transmit pathogens from tree to tree; 100,000 acres have been lost to date, primarily in Florida, from this disease.

Tips on how you can help curtail this disease in California:

· Keep your backyard citrus fruit at home.

· Keep your citrus trees healthy, well-watered and fed.

· Do not move citrus fruits or nursery trees out of your area.

· Report any suspected trees with HLB to your local Ag inspectors and go online to learn more.

· Spread the word of this disease to neighbors and friends.

Shifting weather patterns are moving the bug world around these days, and it is important to understand the big picture on how the flora and fauna, including bugs, are affected by the weather globally.

Trees are a living organism just like people, and we should care for them with periodic attention, and proper care.

Why not make a New Year's commitment in caring for our earth with passion, stewardship, and awareness.

The Tree Man of Fallbrook can be reached at [email protected] or 760-728-4297 for consultations and inspections of your trees.