High carbon dioxide atmospheres combined with high temperature were effective for controlling Indian meal moth, Plodia interpunctella (Hübner) pupae. Pupae were exposed to atmospheres of 60, 80, or 98% carbon dioxide (CO₂) in nitrogen (N₂), or 60 or 80% CO₂ in air at temperatures of 26.7°C or 32.2°C and 60% RH. Controlled atmosphere treatments at 32.2°C controlled pupae faster than the same treatments at the lower temperature. At both temperatures high CO₂ concentration treatments combined with nitrogen killed pupae faster than high CO₂ concentration treatments combined with air. Exposure to 80% carbon dioxide mixed with nitrogen was the most effective treatment causing 100% mortality in 12 h at 32.2°C and 93.3% mortality in 18 h at 26.6°C. High-temperature controlled atmosphere treatments had no adverse effects on quality of two preserved floral products, Limonium sinuatum (L.) and Gypsophila elegans (Bieb.), tested for 12, 18, and 24 h according to industry standards.