Stem-girdler
Guides
Spissistilus festinus
threecornered alfalfa hopper, three-cornered alfalfa hopper
Spissistilus festinus is a treehopper species in the family Membracidae, commonly known as the threecornered alfalfa hopper. It is a significant agricultural pest of leguminous crops, particularly alfalfa, soybeans, and peanuts, causing damage through stem girdling. The species has gained additional economic importance as the confirmed vector of Grapevine red blotch virus (GRBV), a pathogen threatening North American viticulture. Two distinct genetic lineages exist in the United States—Southeastern and Californian—with documented differences in viral transmission efficiency. The species exhibits a hemimetabolous life cycle with temperature-dependent development rates and uses substrate-borne vibrational signals in mating communication.