Elm leaf beetle
Xanthogaleruca luteola
8 host plants
Last updated
Elm leaf beetle larvae skeletonize American elm leaves, leaving a lacy, brown pattern as they consume tissue while veins remain. You will see yellow-green adult beetles with dark spots and a broad stripe along each wing edge feeding on leaves. Larvae are black or black-and-yellow, covered with tiny bumps. Damage appears in spring as larvae feed on new foliage; heavy infestations can defoliate entire trees.
Promote natural parasitoids and predators that control beetle populations. Prune out and destroy infested branches if caught early. Horticultural oil applied in dormancy reduces overwintering beetle numbers. Chemical control is rarely necessary for landscape trees due to generally low pest pressure. Most elm trees in home gardens tolerate moderate leaf loss without serious harm. Focus management on maintaining tree vigor through proper watering and avoiding unnecessary wounding.
Quick Reference
Adults chew entirely through the leaf, often in a shothole pattern. Larvae skeletonize the leaf surface, causing damaged foliage to turn brown to whitish (Figure 4). Elm leaf beetles, when abundant, can entirely defoli- ate large elm trees, which eliminates summer shade and reduces the aes- thetic value of trees. Repeated, exten- sive defoliation weakens elms, caus- ing trees to decline.
Cultural Controls
- Plant resistant cultivars of American elm (Ulmus americana) including 'Dynasty', 'Princeton', 'Prospector', 'Frontier', and 'Pathfinder' (NOTE: Many American elm cultivars are highly susceptible to Dutch elm disease.) Other elms reported to be somewhat resistant to elm leaf beetle feeding include Chinese (U.
- parvifolia) and the elm-like zelkovas (Zelkova spp.) Provide proper culture to maintain plant health.
- Healthy plants are more tolerant of insect damage.
- Prune dead and dying branches in late fall or winter.