Development - temperature relationship and temperature dependent parameters of German cockroach, Blattella germanica L

German cockroach, Blattella germanica L., is one of the most health pests around the world. Development-temperature relationship and temperature-dependent parameters of B. germanica were determined in present study. The experiment was conducted in the incubators with five constant air temperatures, 23, 28, 31, 36, and 40 degrees Celsius. The photoperiod of 16 h light / 8 h dark and the relative humidity of 74%-76% were fixed for all incubators. Three replicates were set for each temperature. Based on linear regression equations, the estimated starting temperature for development of 1st to 5th instar nymphs of B. germanica is 14.26+-3.157, 13.70+-2.284, 14.59+-3.575, 16.58+-2.398, and 18.47+-1.442 degrees Celsius, respectively. The estimated effective accumulated temperature of 1st to 5th instar nymphs is 99.18+-19.68, 97.01+-13.47, 92.06+-21.17, 80.26+-9.784, and 64.06+-9.784 d degrees Celsius (day degrees), respectively. B. germanica had the highest survivorship and hatching rate, and the least instars for eclosion and hatching time, around 31 degrees Celsius, which is the optimum temperature range for development and survival of B. germanica. B. germanica could not survive at 40 degrees Celsius. Even at 36 degrees Celsius, all eclosed adults had vestigial wings and could not normally mate and reproduce.