The phyline plant bug Keltonia robusta Henry previously has been known only from the Florida Panhandle where it is found on the woody mint Conradina canescens Gray (Lamiaceae). New records of the mirid are given from xeric sand communities of peninsular Florida and southeastern Georgia. A new host plant is scarlet basil, Clinopodium coccineum (Nutt. ex Hook.) Kuntze; Lamiaceae), a woody mint on which the bug develops in Georgia. Conradina canescens is the host in the Lake Wales Ridge of the Florida peninsula. Overwintered eggs hatch as early as late March in Georgia, and nymphs apparently feed on the new shoots. First-generation adults appear about mid-May. Reproduction in this multivoltine bug occurs throughout spring and summer, with late instars sometimes found as late as early November and adults persisting until mid-November.