• Home
  • About Us
  • We’re Hiring!
  • Our Services
  • Resources
    • Tree Species
    • Common Problems
    • Additional Resources
  • Articles
  • Request a Consultation
  • 303.554.7035

303.554.7035

"Keep a green tree in your heart and perhaps a singing bird will come."

- Chinese proverb

Get in touch for a Free consultation We can save your ASH!

Your friends and neighbors trust Taddiken for expert tree care service. Let's talk about your trees.

Search

Articles

  • Pinyon Pine, A Colorado Tree
  • Wu Shipher, National Taiwan University; Aphid giving live birthCold Spring, Trees and Aphids
  • Spring Is Transpiring
back to tree problems

Leaf Miner-Tunnels in Leaves

Leaf miners produce two main types of mines: serpentine and blotch. Serpentine mines look snake like as they trail back and forth through the leaf whereas blotch mines bleed together and form a irregularly-shaped spot.

Leaf Miner- Tunnels in Leaves

Leaf miners describe a group of insects that range across multiple insect orders including moths, sawflies, flies, and beetles. Typically only a nuisance, leafminers are more aesthetically displeasing to humans than harmful to the trees. The most common trees affected by these pests are Siberian Elm, Bur Oak, and Hawthorn.

Identification

From a distance, the tree canopy will appear to be browning out. Upon closer investigation, the individual leaves will look clear or almost translucent. When the leaf is examined in the hand it will be noted that it is actually hollowed out in the middle like an envelope. When held to the light, it is noticeable that the top and bottom of the leaf will be intact, but clear, and the center will be filled with little black granules and worms if it is June or early July. A very common statement from our customers is that, “Worms are raining down on us!” This can also happen with Brown Headed Ash Sawfly. However, those larvae are generally fatter and greener and only attack the Fraxinus (ash) species of trees.

Clifford Sadof, Purdue Entomology; Blotch leaf mine
Blotch leaf mines
Clifford Sadof, Purdue Entomology; Elm flea weevil leaf mine

Life Cycle

Females lay eggs on leaves of host plants. The larvae hatch and immediately begin tunneling under the epidermis of the leaf. They feed until just before the pupal stage when they exit the leaf and drop to the ground. After the pupal stage, they emerge as flying adults and begin the cycle again.

Damage

Typically, the damage is minor. Because the larvae consume the photosynthetic machinery of the plant (chloroplasts), severe infestations can be stressful on trees since food production for the tree is diminished. If left untreated for several years of severe attacks, trees can become vulnerable to other pests and diseases.

Management

Conventional

Identification of the leafminer pest is crucial for most control options. A systemic treatment with imidacloprid is the most effective treatment on most leafminer pests (except for moths). Because the larvae are inside the leaves they are well protected from most methods of control. Systemic treatments act through the vascular system of the plants themselves and become available to feeding insects in the cells where they feast.

Moth leafminers are not affected by applications of imidacloprid. A systemic application of acephate, chlorantraniliprole, or acetamiprid can be made. However, insecticidal intervention is typically not necessary as natural enemies tend to catch back up with the high populations.

Cultural Practices

Proper watering and annual soil treatments can reduce the likelihood of outbreaks.

Print Friendly, PDF & Email

Professional Affiliations



  • Int'l Society of Arboriculture


  • Tree Care Industry Association
  • © 2020 Taddiken Tree Company
  •  1726 North 63rd Street, Boulder, CO 80301
  • office@taddikentree.com
  • 303.554.7035