Cucurbit yellow vine disease (CYVD), caused by the squash bug-transmitted bacterium Serratia marcescens, causes a vascular wilt leading to plant death. The goals of this research were to 1) confirm the presence of CYVD in Georgia; 2) characterize the genetic diversity of phytopathogenic and nonpathogenic strains of S. marcescens; and 3) understand the vector/bacterium interactions and, using row covers, the effect of plant age on disease incidence. S. marcescens strains were recovered from symptomatic plants and confirmed as the CYVD pathogen. Genetic analysis indicated that CYVD-associated strains of S. marcescens recently diverged from a common ancestor. Epidemiological studies showed that overwintering squash bugs frequently harbored the pathogen and could acquire it during any instar. Row cover trials demonstrated that plant age is positively correlated with disease resistance and that flowering is the optimal time for row cover removal.