Technical Abstract: The life cycle and biology of Thrips florum Schumtz, an actionable quarantine pest, was studied on gardenia flowers to facilitate timing of control procedures. In laboratory tests, the development period from egg to adult female required a minimum of 17 days at 20°C and 11 days at 24°C. In controlled humidity tests, only 19% of T. florum survived a 24-hour exposure to 92.5% relative humidity, whereas this level was tolerated by >90% of western flower thrips, Frankliniella occidentalis (Pergande). In the field, removing all open gardenia blossoms once per week was associated with large reductions of thrips and damage to flower buds, the marketable commodity.