Atmospheric CO2levels are anticipated to rise from the current ambient level of ca. 350 µl/liter to 500–600 µl/liter in the next 50 to 75 years. Plant scientists are artificially enhancing the CO2environment of crop plants to increase photosynthesis, which is currently limited by inadequate levels of CO2. It is not known how increases of CO2might affect consumers in the food chain. Population levels of sweetpotato whitefly (SPWF),Bemisia tabaci(Gennadius), were assessed with sticky traps placed in a field experiment wherein cotton was grown in open-top field chambers that were enriched with CO2at levels approaching 200% ambient concentration levels. Although trapping started at the first of June, only an occasional SPWF was caught until early August. At that time populations began to increase at an exponential rate similar to that observed in commercial cotton fields in Arizona and California in previous years. There was no difference in rate of buildup of SPWF in ambient and CO2-enriched chambers in either wet or dry irrigation treatment. Thus, it seems that raised CO2levels, either natural or artificial, do not affect SPWF populations.