Tag hackberry leafrollers

Hackberry Leafrollers are Back!

by Texas Tree Surgeons Tree Health Care

 In September 2022, we saw an infestation of small, green worms and their webs on hackberries in North Texas. With the reappearance of the hackberry leafroller moth larvae in August 2023, our recommendations for how to deal with them are a little different.

What’s Changed?

While we usually see hackberry leafroller caterpillar activity in the fall, in 2023, we are beginning to see them while we are still in the heat of summer. Additionally, many hackberries in the DFW are are still recovering from leafroller activity last year and have damaged canopies as a result. The intense heat and drought conditions of 2023 have resulted in an urban forest that is already under extreme stress. Hackberry trees that would normally handle leafrollers easily are now less capable of resisting the pests’ damage. Additionally, there are new recommendations for chemical controls.

What Can We Do about Hackberry Leafrollers in 2023?

While there are no insecticidal treatments that are effective against hackberry leafrollers once the webs appear, it is important to take steps now to ensure that trees bounce back from an infestation and are better prepared for next year.

  • Do not apply a spray insecticide to try to kill the caterpillarsThis is not generally effective and will offer no long-term benefits
  • DO NOT USE HIGH NITROGEN FERTILIZERS.
    • These products cause trees to rapidly put out new growth which can use up the energy stores the trees need to resist pest activity
  • NEVER USE “WEED AND FEED” PRODUCTS near your trees
    • Especially during times of drought and reduced moisture, adding herbicides to the soil can be deadly to trees that are already suffering from a lack of nutrients and other resources
  • If possible, remove any visible caterpillars and their webs
    • Properly dispose of leafroller larvae by burning or by bagging in plastic and putting in the garbage.
  • WATER, WATER, WATER!
    • Proper watering, and even aggressive watering during extended dry periods, is the most important step you can take to bolster your trees’ health
  • Apply soil amendments to help increase the amount of nutrients in dry, desiccated soil
    • Organic products can be utilized that do not contain an excessive amount of nitrogen and will not cause unsustainable growth
    • Installing mulch and compost around your trees is always a good idea, as it helps the soil maintain a constant temperature and moisture level, and it adds nutrient-rich organic material
  • Consider applying systemic insecticides in the late winter or early spring that can help inoculate your trees
    • It is important to introduce insect control measures into the tree’s circulatory system at the appropriate time
  • Contact a local ISA Certified Arborist® to evaluate your trees and make specific recommendations
    • Hackberry trees are prone to a fungal root rot caused by Kretzschmaria deusta and are made more susceptible when stressed by other factors
  • In the spring, evaluate trees to remove any dead wood and assess health

Treat for Leafrollers in the Late Spring or Early Summer

Hackberry leafrollers only have one generation per year, laying eggs on tree leaves in the fall, which hatch the following year. In North Texas, this occurs around May. Within a few weeks of the hatching, a soil-injected product containing acephate can be used, with a possible second application after a few weeks if activity is still seen. If you see leafroller webs this year, contact an arborist to get on the schedule for pesticide application next spring.

At Texas Tree Surgeons, we love trees and we love our community! This summer has been rough on all living things in North Texas and we are saddened to see another threat to Hackberry trees has become active while we are still dealing with drought and heat. Our team of certified arborists is ready to come out and assess your hackberries and all your trees to provide recommendations for soil amendments and insect control tailored to their specific needs. Contact us today!

What are These Small, Green Worms Hanging Off My Trees?

by Texas Tree Surgeons Resources, Tree Health Care


In the spring and fall, we often get calls about small, green worms or caterpillars hanging on web-like threads from trees and structures. While they may be off-putting, and can be rampant some years, they should not be a cause of serious concern.

So, What are They?

While there are many similar-looking small caterpillars and worms, the variety most commonly seen in North Texas is the cankerworm. These inchworm-like caterpillars are the larvae of moths, usually the hackberry leafroller moth (Sciota celtidella). While the leafroller caterpillars usually emerge in the spring, depending on the weather they can also be active in the fall. The caterpillars spin thin strands of web-like filament that they use to move from tree to tree and to aid in feeding.

Should I be Worried?

While the hackberry leafroller can cause defoliation, there is little cause for concern. Healthy trees in good soil can withstand extensive defoliation. While trees that are under stress may suffer more from unseasonal leaf loss, hackberries are hardy, native trees in North Texas and will likely recover during the next growing season. In areas of high activity, the ground may be temporarily discolored, but this should clear up after the next heavy rain.

All About Hackberries

Hackberry trees are a common sight in DFW, and have even lent their name to several areas and neighborhoods! What we call hackberries may be of a few distinct tree species, but are all in the genus Celtis. Hackberries are fast-growing softwood trees that can often be found as volunteers along fences and hedgerows, grown from seeds dropped by birds and other animals that feed on the trees’ berries. Because of their fast growth and structure, and because they are often overlooked, hackberries can be prone to limb and trunk instabilities. One particular danger is root rot caused by the Kretschmaria deusta fungus.

Should I Do Anything?

Unfortunately, once the caterpillars emerge and begin feeding there are no effective insecticidal treatments. Using a water hose or other method to remove caterpillars from trees and structures can help some, but it is important to make sure that the removed caterpillars are disposed of so that they don’t simply re-infest the tree. Proper maintenance, especially of stressed trees, is usually all that is needed to ensure a hackberry recover from leaf rollers. Water correctly and avoid high-nitrogen fertilizers, opting instead for organic soil amendments to improve the tree’s microenvironment. As the population of leafroller caterpillars varies from year to year depending on environmental and other factors, preventative treatment is usually not recommended, due to low success rate and risk of over-usage of insecticidal chemicals.

At Texas Tree Surgeons, we love trees and we love our community! While it’s always a little startling to see unseasonal leaf drop, losing leaves doesn’t necessarily mean a tree is doomed! We are always happy to have one of our ISA Certified Arborists out to look at your hackberries (or any other trees) and let you know if what you are seeing needs to be addressed. Get in touch today!