Temperature-dependent development and reproduction of Tarsonemus confusus (Acari: Tarsonemidae): an important pest mite of horticulture.

ABSTRACT

The tarsonemid mite Tarsonemus confusus Ewing has become an economically important pest in orchards in China. This study investigated the temperature-dependent development and reproduction of T. confusus at 15, 20, 25, 30, 33 and 35 °C. Eggs failed to hatch at 35 °C. When temperature increased from 15 to 30 °C, the developmental rate of eggs, larvae and quiescent larvae and that from egg to adulthood of both sexes significantly increased, and the time period required by females to commence oviposition significantly decreased. The lower temperature threshold (T0) for the development of eggs, larvae and quiescent larvae was between 9.3 and 12.0 °C and both sexes required about 60 degree days (DD) to complete a life cycle. Females were expected to start oviposition at 12.9 °C. The number of eggs laid, the number of female offspring produced and the egg hatch rate were significantly higher at 20, 25 and 30 °C than at 15 and 33 °C. Increasing temperature shortened the longevity of both sexes but increased the intrinsic rate of increase (rm) and finite capacity for increase (λ) with significantly shorter generation time (T) and doubling time (DT) within a temperature range of 15-30 °C. The net reproductive rate (R0) was highest at 25 °C. Results of this study may improve our knowledge of fundamental biology and ecology in genus Tarsonemus in general and in T. confusus in particular. Based on the local climate conditions, the applications of these results in predicting the seasonal population dynamics of T. confusus and timing the pest management are discussed.