Developmental times and survivorship of tarnished plant bug nymphs, Lygus lineolaris (Palisot de Beauvois), and longevity and reproduction of adult tarnished plant bug adults reared on green beans were studied at multiple constant temperatures. The developmental time for each life stage and the total time from egg to adult decreased with increasing temperature. Eggs required the longest time to develop followed by fifth instars and then first-instars. Total developmental time from egg to adult was shortest at 32°C, requiring 18.0 ± 0.3 d and 416.7 ± 31.3 DD above 7.9°C, the estimated minimum temperature for development from egg to adult. Sex did not affect total developmental times and did not affect median survival time. Adults lived significantly fewer days at high temperatures (30–32°C: 17–19 d) compared with temperatures below 30°C (range: 24.5–39.4 d) and the number of eggs laid per day increased from ≈4 at 18°C to a maximum of 9.5 eggs per day at 30°C Total egg production over the lifetime of female tarnished plant bugs increased with temperature reaching a maximum of 175 eggs on average at 27°C, total egg production declined at temperatures above 27°C (30°C: 110.8, 32°C: 77.3 eggs per female). The highest net reproductive rate 74.5 (R₀) was obtained from insects maintained at 27°C. The intrinsic rate of natural increase (r_m) increased linearly with temperature to a maximum value of 0.1852 at 30°C, and then decreased at 32°C Generation and doubling times of the population were shortest at 30°C, 21.0 and 3.7 d, respectively.