Elm Leaf Beetle

ELB is a beetle that is about 1/4 inch long, slender, yellow-green with black stripes (Image 1). There are also two black spots on the head and thorax (Image 2). These beetles feed on almost all elms, but Siberian and American elms are their favorite.

Adults overwinter in protected outdoor areas as well as indoors if they can find a way in. This is when they are a nuisance pest, in both the fall and the spring when they become active again. As temperatures rise the adults are attracted to elms where they feed, mate and lay eggs. The eggs hatch and the larvae emerge (Image 4), Both adults and larvae feed on the leaves causing a skeletonizing of the leaf (Images 3 & 4). There are two generations per year, and both adults and larvae may be present at the same time. Larvae crawl down and pulpate in the soil at the base of the tree.

Two other pests common on elms are the Larger Elm Leaf Beetle (Image 5) and Elm Flea Weevil (Image 6). These both have only one generation per year and similar controls should be effective.


Multiple strategies may be necessary to achieve the desired amount of control.

First is ferti•lome® Tree & Shrub Systemic Insect Drench. This product can reach the highest leaves of the tree and is effective on both adults and larvae as they feed on them. One application can last up to a year.

Spraying can be done in many different locations. On small trees an application of Natural Guard® Brand by ferti•lome® Spinosad orNatural Guard® Brand by ferti•lome® Spinosad Soap can be very effective on larvae and the adults. Hi-Yield® Garden & Farm Insect Control, formerly Hi-Yield® Lawn, Garden, Pet & Livestock Spray can also be applied on small trees and trunks.

Trunk applications can be made before larvae travel down to pupate. Make at least a one foot band of Hi-Yield® 38 Plus or ferti•lome® Broad Spectrum Insecticide, spraying the trunk thoroughly. Repeat 2 to 3 weeks later.

In the fall, treat the foundation of the house and buildings to prevent ELB from coming in. Use Hi-Yield® 38 Plus or Hi-Yield® Bifenthrin Bug Blaster II for the longest lasting residue. Repeat application in 2 to 3 weeks if warm weather persists.

Inside the home, apply ferti•lome® Indoor/Outdoor Multi-purpose Spray around doors, windows and baseboards where insects are present.


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