4 Worst Garden Pests in Dallas

Aphids

The humid subtropical climate that makes Dallas such a great place for gardening enthusiasts, also makes it inviting to the bane of all gardeners – pests. “Big D” and its sprawling Metroplex get all the usual suspects when it comes to annoying and damaging insects. Texas A&M entomologist Dr. Michael Merchant lists the worst of them.

1. Aphids

These tiny insects (pictured above) are not at the top of the list because they start with the letter A. They can wreak havoc in a garden in no time. The female aphid can produce 50 to 100 offspring in her short life, most of which are daughters that start doing the same thing within a week of hatching.

Dr. Michael Merchant
Dr. Michael Merchant

They’re among the first bugs to show up in spring and go right to work, sucking the life out of tender shoots and leaves. Healthy trees and shrubs can withstand an aphid invasion, but the bugs will wilt and wither vulnerable young plants.

As an added annoyance, aphids produce a sweet waste called honeydew. It sticks to plants, outdoor furniture, cars, and windows and ultimately spawns a black mold that makes everything ugly. Ants love the honeydew, and in true Texas style, will wrangle herds of aphids to keep a supply of the sweet stuff. You’ll find aphids clustered under leaves. When you do, it’s imperative you get rid of them ASAP. Several beneficial bugs – such as the charming little ladybugs – feast on aphids but can rarely keep up with the species’ remarkable reproduction rate.

How to get rid of them

Merchant recommends treatments that contain imidacloprid, which kills aphids and other small, soft-bodied pests. “It has low toxicity levels and is available in commercial pesticides such as Bayer Tree and Shrub.” For a more environmentally friendly solution, he suggests neem oil or insecticidal soaps. “Whichever you choose, you have to zap the spray directly onto the bugs or it won’t do any good.” Plan on follow-up treatments until you no longer see signs of infestation.

2. Emerald Ash Borers

Emerald ash borer
Emerald ash borer

This is a relative newcomer on the list, first showing up in Texas in 2016. It’s a little shiny green beetle that feeds on and infects ash trees. “They’re in Tarrant County,” Merchant said. “They have the potential to wipe out all ash trees in the region within 10 years.” The early infestation is hard to spot, and some trees will be too far gone to save.

How to get rid of them

Pesticides containing imidacloprid, such as Bayer Advanced 12 Month Tree and Shrub and Bonide Annual Tree & Shrub Insect Control, can be effective if the infestation is caught early. If not, the tree should be removed.

3. Bagworms

Bagworm
Bagworm

If you have evergreen trees, you’ve probably seen these pests – or at least their nests. Adult males become hairy black moths in late summer, but these creatures do their damage in their caterpillar stage. They winter in easily recognizable cocoons woven from bits of grass and stems that hang from tree branches. The caterpillars that emerge in spring chew up the tree. Evergreens are most vulnerable, but other trees such as live oak, elm, maple, and sycamore can also become infected. Left untreated, evergreens can become so defoliated that limbs have to be amputated and in severe cases, the tree has to be cut down.

How to get rid of them

Timing is everything. If you spot the cocoons in winter or spring before the caterpillars have emerged, you can pluck them off the tree and smash them. But you won’t likely get all of them. If the caterpillars are mobile, commercial products containing pyrethroid and Bacillus thuringiensis (Bt) are effective and relatively nontoxic.

4. Spider Mites

Red spider mites
Red spider mites. Credit: Aleksy Gnilenkov, CC 2.0

These creatures are so small it’s hard to see them without a magnifying glass. They’re distant cousins of spiders but get their name from webs they spin on the plants they infest. They range in color from bright red to yellowish, and while they were first noted in Europe, they have spread worldwide to wherever they find a favorably warm climate. The presence of these webs and stippling they produce when they suck on leaves is the best way to spot them. Spider mites are not particularly choosy when it comes to eating, so many of your garden plants could be at risk. They also love hot, dry weather – which is abundant in Dallas.

How to get rid of them

Spider mites are tough to control. Their tiny size and preference for the undersides of leaves keep them hidden, and they tend to adapt to pesticides.  In fact, some pesticides actually increase the population. Insecticidal oils and soaps and neem oil can be helpful. Mites’ natural enemies, such as the ladybug, can help control them. The best way to eliminate them is to put a pressure nozzle on your garden hose and blast them away. Merchant says one way to ward off harmful pests is to keep your lawn and plants healthy. Regular mowing, watering and fertilizing are essential. “Plants that are healthy and vigorous are less vulnerable to pests,” Dr. Merchant said. “Choose plants that are well suited to the area or native plants. Native plants harbor native insects, birds, and lizards that can be beneficial.”

Lynn Walker

Lynn Walker

Lynn Walker has been writing for radio, TV and newspapers for more than 50 years, and has expertise in news, features, humor, history, weather, genealogy, science, archaeology and government.