Fall Webworm Treatment in North Texas Trees

Fall webworms are a fixture of the North Texas summer and fall landscape, with their large silken webs appearing on the branch tips of pecans, persimmons, sycamores, and scores of other tree species from midsummer through October. The webs are visually alarming, often growing to several feet in diameter as the season progresses, and the sight of brown dead foliage enclosed in silk is enough to prompt urgent calls even when the actual threat to the tree is relatively modest. Understanding when webworm pressure genuinely warrants professional treatment and when natural tolerance is sufficient is exactly the kind of judgment that requires a certified arborist with North Texas field experience. Trees Hurt Too, Inc. evaluates webworm infestations throughout the DFW area, assesses the actual impact on tree health in the context of any other stressors present, and provides targeted treatment when the situation warrants it.

"Webworms are one of those pests where I spend as much time helping people understand what not to do as what to do. Do not burn the nests. That approach damages the bark and branch tissue beneath the web and creates real fire risk. The other thing I see regularly is people spending money on treatment for late-season webworm infestations on large established trees that are not in any real danger. The evaluation determines whether you are dealing with a cosmetic annoyance or a genuine health threat, and that distinction matters for making the right decision." Ken, ISA Certified Arborist Tx-3265-A | Owner, Trees Hurt Too, Inc.

We provide free on-site evaluations throughout North Texas. Call (972) 521-1552 if you see large silken webs on your trees, or visit our Tree Health Care and Arborist Services page.

Understanding Fall Webworms in North Texas

Fall Webworm Biology in the DFW Climate

Fall webworms, Hyphantria cunea, are native North American caterpillars that overwinter as pupae in bark crevices and soil and emerge as adult moths in spring and early summer. North Texas's warm climate allows two or more generations per year, meaning webworm pressure can persist from midsummer through October in some years. Adult female moths lay egg masses on the underside of leaves, and the newly hatched caterpillars immediately begin constructing a communal silken web over the surrounding foliage. The colony feeds, grows, and expands the web through the season. Mature caterpillars leave the web to pupate in bark or soil and begin the next generation.

Why Webworms Are More Visible Than Dangerous

Fall webworms time their feeding to the latter portion of the growing season when trees have already completed most of their annual growth and nutrient production. Deciduous trees that lose foliage in fall can tolerate late-season defoliation better than spring defoliation because the energy production season is largely complete. This is why large, healthy, established trees in North Texas often sustain repeated webworm infestations without measurable long-term decline, despite the alarming appearance of the webs.

When Webworms Become a Genuine Concern

• Heavy infestations on trees that are already stressed by drought, soil compaction, disease, or other conditions compound the total stress load and can tip weakened trees toward serious decline
• Early-season infestations that begin in June or July and persist through multiple generations can defoliate trees during the peak production period
• Young or newly established trees with limited energy reserves are more vulnerable to repeated defoliation than mature established trees
• Pecan trees with heavy infestations affecting nut crop production have an economic impact beyond the tree health concern

Most Commonly Affected Species in North Texas

• Pecan trees throughout all DFW communities where pecans are grown
• Persimmons including both native and ornamental varieties
• Sycamores and plane trees
• Oaks of multiple species
• Walnuts and sweet gums
• Many ornamental trees planted throughout residential landscapes

Identifying Webworms and Distinguishing Them from Tent Caterpillars

Fall Webworm Identification

• Large, loosely constructed silken webs enclosing foliage at the outer tips of branches
• Webs typically start small in early summer and expand through the season as the colony grows
• Brown, dirty appearance with frass and eaten leaf material visible inside the web
• Caterpillars are pale yellow to greenish with long silky hairs visible on inspection
• Multiple nests on the same tree are common especially later in the season

Key Difference from Eastern Tent Caterpillars

• Tent caterpillars appear in early spring while webworms appear in summer and fall
• Tent caterpillars build tents in branch crotches and forks, not at branch tips
• Tent caterpillars leave their tent to feed on surrounding foliage, while webworms feed inside their web
• Tent caterpillars have a distinctive blue, black, and yellow striped pattern

For a complete visual guide visit our shrub and tree pest control page.

Webworm Treatment Options in North Texas

Bacillus thuringiensis Applications

Bacillus thuringiensis kurstaki (Btk) is a biological insecticide highly effective against young actively feeding webworm larvae when the application contacts them during feeding. Applications work best against early-instar larvae before webs become large and the caterpillars are mature. Btk is selective for caterpillars and has minimal impact on beneficial insects including pollinators when used correctly.

Targeted Insecticide Sprays

For larger infestations or advanced colonies where Btk is less effective, our certified arborist selects appropriate contact insecticides that penetrate the web to reach the feeding colony. Application volume and pressure must be sufficient to contact the caterpillars through the silken web structure.

Physical Nest Removal

Early-season removal of small accessible nests on smaller trees is effective when the colony is young and the nest size is manageable. Removed nests should be destroyed away from the tree. Burning nests is strongly discouraged as it damages the tree and creates fire risk.

Supporting Tree Health

Trees with robust root zone health tolerate webworm feeding pressure more effectively than stressed trees. Our deep root feeding program supports the overall tree vigor that helps North Texas trees maintain tolerance to late-season pest pressure.

Where We Treat Webworms in North Texas

We diagnose and treat webworm infestations throughout the DFW metroplex. Pecan webworms are common throughout communities where pecans are planted including Mansfield, Burleson, Midlothian, and Fort Worth. General webworm infestations occur throughout all communities in Tarrant County and Dallas County.

Frequently Asked Questions About Webworms in North Texas

What are fall webworms and are they dangerous?

Fall webworms are caterpillars that construct large silken webs at branch tips and feed on enclosed foliage from midsummer through fall. They are rarely fatal to established healthy trees because they feed late in the season when most growth is complete. However, heavy infestations on already-stressed trees or young trees can cause serious cumulative damage.

What do webworm nests look like?

Large, loosely constructed silken webs at the outer tips of branches, often brown and containing frass and eaten foliage inside. Webs start small and expand through the season. Multiple nests may appear on the same tree. For a visual guide visit our shrub and tree pest control page.

What is the difference between webworms and tent caterpillars?

Fall webworms appear in summer and fall, build nests at branch tips enclosing foliage, and feed inside the web. Eastern tent caterpillars appear in early spring, build tents in branch crotches, and leave the tent to feed on surrounding foliage. They are distinct species with different timing and behavior.

Which North Texas trees are most susceptible to webworms?

Pecans, persimmons, sycamores, oaks, walnuts, and sweet gums are most commonly infested. Pecan trees are particularly frequently affected throughout DFW wherever pecans are grown.

How are webworms treated?

Treatment options include Btk biological insecticide applications against young larvae, targeted insecticide sprays for larger infestations, and physical removal of small early-season nests. Treatment is most effective early in the infestation against young colonies. Our certified arborist evaluates whether treatment is warranted based on infestation level and tree health status.

Should I burn webworm nests?

No. Burning webworm nests damages the bark and branch tissue beneath the web and creates fire risk. Physical removal of small accessible nests or professional insecticide treatment are the recommended approaches.

Do you offer free webworm evaluations in DFW?

Yes. Trees Hurt Too provides completely free on-site tree evaluations throughout the DFW area with no obligation. Call (972) 521-1552 or request your evaluation through our contact page.

Webworm Treatment Service Area

Trees Hurt Too provides ISA Certified Arborist webworm diagnosis and treatment throughout North Texas. View our complete service area or call (972) 521-1552. For additional information on webworm research visit the Texas A&M AgriLife Extension.