This study was conducted to determine the effect of temperatures on the egg and nymphal development, adult longevity and oviposition of bean bug, Riptortus clavatus Thunberg, using Saealkong seed as food sources in fibrous nylon-tube at four different temperatures (20, 24, 28 and $32^{circ}C$). Hatchability showed the highest value of 100% at $28^{circ}C$ and decreased with increasing temperature. Egg duration ranged from 7 days at $32^{circ}$ to 16.7 days at $20^{circ}C$. Instar duration was longer with increasing instar stage. Nymphal duration was 38 days at $20^{circ}C$, 30 days at $24^{circ}C$, 23 days at $28^{circ}C$, and 18 days at $32^{circ}C$ Emergence rates to adult were 16, 41, 72 and 68% at 20, 24, 28 and $32^{circ}C$, respectively. Female adult longelity ranged from a minimum 20 days at $20^{circ}C$ to a maximum 63 days at $28^{circ}C$, while the longevity of male ranged from 19 days at $20^{circ}C$ to 60 days at $28^{circ}C$. Preoviposition duration was shorter with increasing temperature and ranged from 11 days at $20^{circ}C$ to 5 days at $32^{circ}C$. Total number of eggs laid per female ranged from a minimum 21 eggs at $20^{circ}C$ to a maximum 67 eggs at $28^{circ}C$. Consequently, the estimated lower threshold tempeatures of each developmental stage were $10.3^{circ}C$ for egg, and 9.3, 12.7, 10.0, 11.0 and 8.7 for the 1st, 2nd, 3rd, 4th and 5th instar, respectively.