The developmental time of immature stages of Paromius exiguus (Distant) was investigated at nine constant temperatures (15, 17.5, 20, 22.5, 25, 27.5, 30, 32.5, 35±1℃), 20-30% RH, and a photoperiod of 14:10h (L:D). Eggs did not develop at 15℃, and their developmental time decreased with increasing temperatures. Its developmental time was longest at 17.5℃ (28.2 days) and shortest at 35℃ (5.9 days). The first nymphs failed to reach the next nymphal stage at 17.5 and 35℃. Nymphal developmental time decreased with increasing temperatures between 20℃ and 32.5℃, and developmental rate was decreased at temperatures above 30℃ in all stages except for the fourth nymphal stage. The relationship between developmental rate and temperature fit a linear model and three nonlinear models (Briere 1, Lactin 2, and Logan 6). The lower threshold temperature of egg and total nymphal stage was 13.8℃ and 15.3℃, respectively. The thermal constant required to reach complete egg and the total nymphal stage was 109.9 and 312.5DD, respectively. The Logan-6 model was best fitted (r²=0.94-0.99), among three nonlinear models. The distribution of completion of each development stage was well described by the 3-parameter Weibull function (r²=0.91-0.99).

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