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.