Thermal requirements and biological life table parameters of the predatory mite Amblyseiella denmarki (Zaher and El-Borolossy) (Acari: Phytoseiidae)

Abstract

The biological aspects, thermal requirements and life table parameters of the phytoseiid predatory mite Amblyseiella denmarki fed on Aceria dioscoridis was determined at four temperatures, i.e. 15, 20, 28 and 35°C. The total developmental durations for both females and males were correlated negatively with increasing temperature. The minimum developmental thresholds (T 0) of egg, larva, protonymph, deutonymph stages and life cycle of A. denmarki females averaged 13.15, 4.56, 11.22, 12.72 and 11.80, respectively, while those of males were 12.40, 3.01, 9.82, 10.88 and 10.04. On the other hand, females and males required 89.28 and 93.45 degree days (DD), respectively, to reach adulthood. The male life span averaged 63.32, 49.25, 25.39 and 18.26 days while that of female was 90.51, 64.44, 29.51 and 19.99 days when the predator was reared at 15, 20, 28 and 35°C, respectively. The mean generation time (T) averaged 38.84, 24.87, 9.24 and 8.56 days, and the net reproductive rate (R 0) values were 3.79, 10.042, 26.488 and 7.172 when the predator was kept at 15, 20, 28 and 35°C, respectively. The net rate of natural increase (r m) was 0.032, 0.092, 0.354 and 0.230, whereas the finite rate of increase (e rm) averaged 1.032, 1.097, 1.425 and 1.258 at 15, 20, 28 and 35°C, respectively.