Cottonwood Leaf Beetle (Chrysomela scripta)
Detailing the identifying qualities of the Cottonwood Leaf Beetle, including physical features and territorial reach.
Updated: 8/1/2017; Authored By Staff Writer; Content ©www.InsectIdentification.org
True to its name, the Cottonwood Leaf Beetle can be found in groves and forests of cottonwood trees where its caterpillar will feast into maturity.
Cottonwood Leaf Beetles have thick black stripes and spots on their elytra (wing covering). They have similar coloring to the pesky Colorado Potato Beetle, but a very different pattern making it easy to differentiate between the two. Adults are active in the spring when females begin laying groups of yellow, tubular fertilized eggs on the new leaf growth of cottonwood and willow trees. The larval caterpillars will feed on the leaves until they are developed enough to pupate. They then cocoon themselves right-side-up on leaves and emerge as adults in a relatively short span of time. In warmer regions, as many as 4 or 5 generation can be produced each year.
Caterpillars are yellow with segments and side ridges that almost resemble the texture of alligators. Each ridged segment has a black dot and the tips share a black line that runs from head to rear. They chew the green parts of a leaf, leaving behind the veins, giving the leaf a skeleton-like appearance. Large numbers of Cottonwood Leaf Beetle caterpillars can defoliate young trees, harming their health and growth. Removing weeds in the vicinity of the trees where adults overwinter can help reduce the amount of reproduction that occurs in the spring. Spraying chemical insecticides on the affected tree can also control populations of this beetle.