| Leaf miners are a nuisance that are more | | | | larvae hatch and immediately begin tunneling under |
| aesthetically displeasing to humans than harmful to | | | | the epidermis of the leaf. They feed until just |
| the trees. The most common trees effected by | | | | before the pupae stage when they exit the leaf |
| this pest are: | | | | and drop to the ground. After pupae stage they |
| Siberian Elm | | | | emerge as flying adults and begin the cycle again |
| Bur Oak | | | | DAMAGE |
| Hawthorn | | | | Typically the damage is minor. Because the |
| IDENTIFICATION | | | | worms feed on the chlorophyll in the leaf cells |
| From a distance the tree canopy will appear to be | | | | severe infestations can be stressful on trees |
| browning out. With a closer look the individual | | | | since food production for the tree is diminished. If |
| leaves will look clear or almost translucent. When | | | | left untreated for several years of severe |
| the leaf is examined in the hand it will be noted | | | | attacks trees can become vulnerable to other |
| that it is actually hollowed out in the middle like an | | | | pests and diseases. |
| envelope. The top and bottom of the leaf will be | | | | MANAGEMENT |
| intact, but clear, and the center will be filled with | | | | Conventional: The most effective treatment is a |
| little black granules and worms if it is June or early | | | | systemic insecticide called imidicloprid. Because the |
| July. A very common statement from our | | | | worms are inside the leaves they are well |
| customers is that, "Worms are raining down on | | | | protected from most methods of control. |
| us!" This can also happen with Brown Headed Ash | | | | Systemic treatments act through the vascular |
| Sawfly, however those worms are generally | | | | system of the plants themselves and become |
| fatter and greener and only attack the fraxinus | | | | available to feeding insects in the cells where they |
| (ash) species of trees. | | | | feast. |
| LIFE CYCLE | | | | Organic: None known. |
| Females lay eggs on the leaf of host plants. The | | | | |