This study aimes to investigate the effect of constant and fluctuating temperatures on starting times of developmental periods of insect species. For this purpose, Sarcophaga (Liopygia) argyrostoma (Robineau-Desvoidy, 1830), a forensically important species has been chosen. Whether the constant (25 degrees C) and fluctuating (25.2 degrees C averaged over natural conditions) temperatures would make a difference on the timing of intrapuparial development of this species was investigated. First larval instars were placed in rearing cages until they reached post-feeding third larval instar, which is considered the beginning of intrapuparial development. Relevant morphological changes were observed by hourly dissections. At fluctuating temperature treatment, the post-feeding third instar larvae were transferred to containers under natural, open-air conditions. Minimum and maximum starting times of 23 intrapuparial development periods were determined for both treatments. These times, medians, and standard deviations were compared by Mann-Whitney U tests. Accumulated degree hour values were also calculated for these periods. Regardless of temperature treatment, intrapuparial development periods were similar and adult emergence was observed at 289.5 ( +/- 1.52) h under 25 degrees C constant temperature and 319 ( +/- 1.41) h under fluctuating temperature conditions. No statistical difference was found between the intrapuparial development of S. argyrostoma reared under constant and fluctuating temperatures, except "pupal-adult apolysis" and "checkered pattern on the abdomen becoming distinct" periods. The use of the results obtained when determining the effect of constant and fluctuating temperatures on the starting times of developmental periods of this species in forensic entomology, is also important in transferring developmental biology data into the field of applied sciences.