What evidence do lacebugs leave behind?

Lacebugs are known for their distinctive feeding habits that leave behind specific signs on infested plants. One of the most telling pieces of evidence is the small, black, varnish-like spots of excrement found on the undersides of leaves. This excrement results from their sap-sucking feeding process as they extract nutrients from the plant tissues. The dark color and glossy appearance of these droppings are characteristic markers of lacebug presence, making them a reliable indicator for identification.

The other options, while they might relate to different pests or conditions, do not specifically pertain to the evidence left by lacebugs. Sticky plant sap is more commonly associated with other sap-sucking insects. Webbing is indicative of spider mites or web-spinning insects, and holes in leaves often suggest feeding by larger pests, like caterpillars or beetles. Understanding the specific signs left by lacebugs can help in diagnosing and managing pest issues effectively in horticultural practices.