Archives April 2020

Another installment in our series of posts where Texas Tree Surgeons answers your tree questions. Are you having problems with your trees and want to know what’s wrong? Let us know!

My cedar tree has bagworms. Can you treat for that?

Bagworms are a common pest in North Texas, especially on cedars, junipers, cypresses, and other evergreens, although they can attack broad-leaf trees (like oaks, maples, and elms) as well. While they are common, they may not always be noticeable, especially on evergreens, as they use material from the trees they infest to camouflage their casings. Like other insects, bagworms have a year-long life cycle, and control measures depend on the growth stage of the pest.

What Are Bagworms?

• Bagworm is the common name for several different species of insect which are actually a type of moth (order Lepidoptera, family Psychidae).
• The bagworm caterpillars are very small (about 1/25 of an inch long), and spin silk thread which they use to attach themselves to plants and to weave into their bags.
  • Unlike a typical cocoon, the bagworm’s casing functions as a moveable shelter, with the caterpillars exiting to find food and climb up the plant.
• Once the caterpillar has matured, it undergoes a metamorphosis period before emerging as an adult.
  • Male bagworms resemble small moths while the females are flightless.
• Male bagworm moths seek out females during mating season, and the female uses her bag to lay eggs.
  • The exact times of caterpillar and adult emergence varies from species to species and is dependent upon the weather.

Can You Treat For Bagworms?

While bagworms are not prevalent every year, once they have infested a tree, they will continue to live there unless controlled.

• The simplest control method is to remove the bags.
  • They can be pulled off by hand or sprayed off with high-powered water.
  • It it important to dispose of the bags or destroy them, and not just leave them lying on the ground, as the eggs they contain can hatch and re-infest the tree.
• Insecticide sprays can be used to control bagworms, but are most effective when the caterpillars are small, and can be completely ineffective if the bagworms close their bags, as they do to molt or over the winter.
  • Systemic insecticides may be used in some cases as a preventative measure. Consult a certified arborist to see if this may be a good option for you.

At Texas Tree Surgeons, we love trees and we love our customers! Bagworms are a widespread nuisance and, while one or two may not harm a mature tree, can cause large-scale defoliation if left unchecked. It is a good idea to remove any bags that you see, whenever you see them. If you have bagworms, and want to see if there might be a chemical treatment option, contact us to set up a visit from a certified arborist. We offer full-service plant health care, including fertilization to help trees stressed by bagworms recover. We look forward to hearing from you!

Another installment in our series of posts where Texas Tree Surgeons answers your tree questions. Are you having problems with your trees and want to know what’s wrong? Let us know!

The leaves on our oak trees are looking diseased, with bumps all over them. Is this oak wilt?

Oaks are the most common trees in our North Texas urban forest, and they can suffer from many different health issues. If your oak is showing misshapen leaves with bright green bulges on them, it is most likely a fungal disease that may look bad, but is not usually harmful to the overall health of the tree.

Oak Leaf Blister 

• Oak leaf blister is caused by the fungus Taphrina caerulescens, which enters the new leaf buds during cool and moist spring weather.
• The fungus causes the young leaves to develop blister-like bumps on their surfaces, with coloration ranging from light green to brown.
  • In more severe cases, the leaves may fall off altogether.
  • The fungus does not affect mature leaves, only new growth.
• Like other fungal diseases, oak leaf blister is more prevalent during periods of cooler weather with increased rainfall in the spring, and cannot survive the summer heat.

Does Oak Leaf Blister Kill the Tree?

Oak leaf blister and the T. caerulescens fungus do not pose a serious risk to the health of affected trees.

Can Oak Leaf Blister Be Treated?

• The spores which carry the oak leaf blister fungus are present on the bud sites over the winter, and once the tree begins showing infected leaves, chemical treatment is not effective.
  • It is possible to apply a preventative fungicide, but this must be done before bud break and while the young leaves are maturing.
• If you have a tree with oak leaf blister, the best course of action is to clean up fallen infected leaves and dispose of them in plastic bags.
  • Do not place leaves in compost, as this may encourage further fungal growth.
• Keeping a tree healthy with proper mulching and fertilization, as well as maintaining soil drainage, will help it resist future health issues.

At Texas Tree Surgeons, we love trees and we love our customers! While oak leaf blister can be unsightly, it is mostly harmless and is not a serious concern to the health of the tree. Of course, there are many oak health issues that can cause long-term damage and tree death. Oak wilt is a major concern. Trimming oaks should be avoided between February and July if possible, and proper precautions taken if trimming cannot be postponed. Oak decline is also a problem, especially in areas where many of the trees were planted around the same time, and are reaching the end of their lifespan. If you have any questions about the health of your oaks, or any other tree care issues, let us know!