Skeletonizing Leaf Beetle
Observed on sweet potato foliage in a subsistence farm at Kitale, Kenya. Oct. 2016.
Some species of leaf beetles feed as larvae (grubs) on the roots of various plants. One of the most notorious for agriculture is the corn rootwoom. As adults they feed on a wide variety of plant leaves, but normally their feeding intensity is of little consequence. Whether this is indeed a rootworm I don't know certainly.