Among the three viruses of the genus Grablovirus in the plant virus family Geminiviridae, insect vector transmission is documented only for grapevine red blotch virus (GRBV), for which Spissistilus festinus (Hemiptera: Membracidae), the three-cornered alfalfa hopper, is identified as a vector. Transmission of GRBV by S. festinus is circulative, nonpropagative; it is also transstadial but neither transovarial, nor via seeds. Here, we thoroughly describe the S. festinus-mediated transmission process of GRBV with Vitis species, the natural hosts of the virus, and Phaseolus vulgaris plants, an experimental pseudo-systemic herbaceous host of the virus.