Treehoppers are interesting looking insects that resemble thorns (see photo above) or buds of plants. They are sucking insects and feed on plant sap by inserting their long, thin mouthparts into plant tissue. Some of the herbaceous plants they may feed on include Dahlia, aster and many others. Female treehoppers insert their ovipositor into the plant tissue to deposit her eggs. She may be observed guarding them. After hatching, the nymphs feed on the plant but cause little injury. The nymphs are very spiny in appearance. These insects rarely cause noticeable injury and do not require control.