Life history of Neoseiulus agrestis (Karg) (Acari: Phytoseiidae) fed on the storage mite, Thyreophagus sp. (Acari: Acaridae) at different temperatures

The development and life history parameters of Neoseiulus agrestis feeding on the storage mite, Thyreophagus sp., were studied at three different temperatures of 20, 25, and 30 & DEG;C. The results show that juvenile development and oviposition period as well as reproductive potential of this predatory mite are significantly affected by the temperature. The development times of immature and the life expectancy of adults ranged from 11.36 to 6.06 days and 58.71 to 38.65 days, respectively, depending on the temperature. The average total number of eggs laid per female at 20 & DEG;C (27.21), 25 & DEG;C (46.38), and 30 & DEG;C (61.12) differed significantly from each other. The highest net reproductive rate (R0) was 51.95 (offspring/individual) at 30 & DEG;C, although there was no significant difference from that obtained at 25 & DEG;C (37.10). Furthermore, the highest intrinsic rate of increase (rm) is 0.286 day-1 at 30 & DEG;C. Moreover, the highest finite rate of increase (& lambda; = 1.331 day-1) and the shortest mean generation time (T = 13.786 days) and doubling time (DT = 2.418 days) were also determined at 30 & DEG;C. Our results indicate that N. agrestis successfully completed immature development and can survive and reproduce at all temperatures tested. However, a number of biological traits of this predator are affected by the temperature on this food source. Finally, a temperature of 30 & DEG;C seems to be more suitable for mass rearing of this predator on Thyreophagus sp. Further studies should be carried out to determine the biological characteristics and life cycle parameters of N. agrestis on various important pests such as spider mites, whiteflies and thrips.