The yellowmargined leaf beetle, Microthecaochroloma (Stål) (Coleoptera: Chrysomelidae ), is an adventive pest of cruciferous crops in the southeastern United States. Despite its pest status, there is limited information about the infiuence of temperature on development and survival of M. ochroloma. The objectives of this study were to assess the effect of temperature on the development and survival of immature stages, and determine the cold tolerance of immature and adult stages. Development was evaluated at 15,20, 25, and 30°C, and cold tolerance was measured at 5,0, and -5°C inside environmentally controlled chambers. Survival of M. ochroloma from egg to adult was ≈80% at 15,20, and 25°C, but only 24% at 30^°C. Mean developmental time was longest at 15°C (57 d) and shortest at 30^°C (17 d). Leaf area consumed by the fourth instar was 7.4-fold lower at 30^°C compared with consumption at 15, 20, or 25°C. The lower developmental threshold varied from 7.3 to 9.8°C and the total degree-days required to complete development from egg to adult was 333. At 5,0, and -5°C, the LT₉₀ values for the first instar were shorter compared with all other stadia, suggesting that the first instar is the most susceptible to cold temperatures. Eggs were most cold tolerant, followed by pupae and adults. Based on the LT₅₀ (13d) andLT₉₀ (38d) of eggs at 0^°C, the predicted northern distribution of M. ochroloma extends to Kansas, Illinois, Kentucky, and Virginia.