Effects of different temperatures on the demography of pistachio green stink-bug, Brachynema germariKolenati (Hemiptera: Pentatomidae), under laboratory conditions

The pistachio green stink-bug, Brachynema germari is one of the most important pests of pistachio in Iran that annually causes significant damages to this strategic crop. In this research, the effects of different temperatures on the demography of B. germari were investigated under laboratory conditions. The experiments were conducted at five constant temperatures [20, 25, 27.5, 30 and 35 (+/- 1) degrees C], on Ohadi cultivar. The lowest and the highest mortality rates in both the eggs and nymph stages were observed at 25 degrees C and 35 degrees C, respectively. The longest and shortest immature development times were observed at 20 degrees C (53.75 days) and 35 degrees C (18.42 days), respectively. The population growth parameters were significantly affected by the experimental temperatures. The gross reproductive rate (GRR) was severely reduced at 35 degrees C and the net reproductive rate (R-0) was also decreased increasing temperature. The intrinsic rate of increase (r(m)) was 0.05, 0.06, 0.06, 0.07 and 0.09 (day(-1)) at 20, 25, 27.5, 30 and 35 degrees C, respectively. Moreover, the lowest finite rate of increase (lambda) (1.05 day(-1)) was observed at 20 degrees C, whereas the longest and shortest mean generation time (T) and doubling time (DT) occurred at 20 degrees C and 35 degrees C, respectively. Finally, the highest and lowest reproductive parameters values, including daily and total fecundity and fertility, were obtained at 20 degrees C and 35 degrees C. The results of this research could be useful in monitoring and efficient control of this pest.