Development and survival of the cheese mites, Acarus farris and Tyrophagus neiswanderi (Acari: Acaridae), at constant temperatures and 90% relative humidity

Two species of acarid mites, Acarus farris and Tyrophagus neiswanderi, have been identified infesting Cabrales cheese in an Asturian maturing cave, the former being the prevalent species. The developmental rate and survival of immature stages of these mites were examined at constant temperatures, ranging from 7 to 29.7 °C for A. farris, and 10 to 31 °C for T. neiswanderi, and a relative humidity (r.h.) of 90±5%. The larval stage of A. farris was particularly susceptible to low and high temperatures with 81.7% and 95.2% mortality at 7 and 29.7 °C, respectively. Tyrophagus neiswanderi larvae also showed the greatest mortality at extreme temperatures among immature stages, though at a lower level than for A. farris (8.6% and 25.6% at 10 and 31 °C, respectively). The optimal temperature for development appeared to be 27-28 °C for both species and the developmental rates were higher for A. farris than T. neiswanderi within the range of the cooler temperatures prevalent in the cheese-maturing caves. The nonlinear Logan type-III model provided the best fit for the relationship between developmental rates and temperature (R_a²>0.99) for all immature stages of A. farris, whereas the development of T. neiswanderi was better described by the Lactin model (R_a²>0.97). The lower and upper developmental threshold temperatures predicted for each stage of A. farris were 3-4 °C lower than those predicted for T. neiswanderi. The differential temperature-development rate for each species might explain the greater abundance of A. farris compared to T. neiswanderi. Furthermore, manipulation of temperature based on modeling predictions may well be used to control mite populations during the cheese maturing process.