Temperature-dependent development and population growth parameters of the fungus gnat, Lycoriella auripila (Winnertz), on button (737 and A15) mushroom were evaluated at nine constant temperatures, ranging from 8, 10, 12.5, 15, 20, 22.5, 25, 27, and 30 degrees C and developmental rates were modeled as a function of temperature. At 25 and 27 degrees C, an average of 20.89 and 22.43 d was needed for L. auripila to complete its development from oviposition to adult eclosion on 737 and A15, respectively. The population failed to survive at 8 and 30 degrees C. The developmental times of males or females on each variety at various constant temperatures differed significantly. The regression and Ikemoto and Takai linear models, in the absence of 10, 12.5, and 27 degrees C, described the relationship of developmental rate to temperature for male and female of L. auripila very well. Data were fitted to various nonlinear temperature-dependent models. The Logan 6 and Briere 1 nonlinear models provided the best estimation for Topt and Tmax and are highly recommended for the description of temperature-dependent development of L. auripila on 737 and A15, respectively. On 737 variety, significant differences were observed among all growth parameters at various temperatures. The intrinsic rate of natural increase (r(m)) for L. auripila was 0.134 on 737 variety at 25 degrees C, which was significantly >0.052 on A15 variety at the same temperature. No other data are available in using linear and nonlinear models to describe the relationship between temperature and L. auripila development. Understanding the influence of temperature on development of L. auripila is discussed with respect to pest management in mushroom production.