NC State Extension Publications

Description and Biology

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Sycamore leaf beetles, Neochlamisus platani, are case bearing leaf beetles that feed on the leaves of sycamore. The adults are small, chunky, and wrinkled but very attractive bronzy beetles shaped somewhat like a caterpillar dropping. Females lay up to 150 eggs from mid May through June. They encase their orange eggs in fecal material on the under side of leaves (sometimes on top and sometimes on petioles). Orange grubs hatch about two weeks later and feed by chewing small holes all the way through leaves that appear as "shot holes" as the leaf expands. Grubs each construct a case from plant material and recycled plant material (frass) into which they can retreat to molt four times as they grow. The case also provides some protection from predators. When molested, grubs hold tightly to the leaf with their claws and mandibles so that a predator sees only the case. When mature, grubs wander to the leaf stipules and cling there where they resemble buds. There they molt into pupae inside their cases, and from the pupal stages adult beetles emerge some days later.

Sycamore leaf beetle (headed right)

Sycamore leaf beetles are very small and only found on sycamore.

Lacy L. Hyche, Auburn University, Bugwood.org

A sycamore leaf beetle (headed left)

Another view of a sycamore leaf beetle.

Lacy L. Hyche, Auburn University, Bugwood.org

Sycamore leaf beetle grub taken from its case

Sycamore leaf beetle grubs are usually hidden inside their cases.

Lacy L. Hyche, Auburn University, Bugwood.org

A sycamore leaf beetle grub hidden by its case

The sycamore leaf beetle grub is completely hidden inside its case.

Lacy L. Hyche, Auburn University, Bugwood.org

Host Plants

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Sycamore leaf beetles feed only on American and London sycamores as larvae and adults.

Sycamore leaf with holes from beetle damage

Sycamore leaf beetles chew holes through leaves.

Lacy L. Hyche, Auburn University, Bugwood.org

Residential Recommendations

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Usually more than a third of sycamore leaf beetle eggs are parasitized by an exceedingly tiny wasp, Tetrastichus chlamytis. Should these beetles become abundant enough to warrant control measures, most of the insecticides sold for landscape use in the plant sections of big box stores and in nurseries and garden centers should give more than adequate control. As sycamores are often infested with sycamore lace bugs, treating for sycamore leaf beetles should help control the lace bugs as well.

Other Resources

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For assistance with a specific problem, contact your local N.C. Cooperative Extension Center.

This Factsheet has not been peer reviewed.

Author

Professor Emeritus
Entomology & Plant Pathology

Find more information at the following NC State Extension websites:

Publication date: March 6, 2019
Revised: Dec. 20, 2023

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