| The current study was conducted at the Department of Plant protection, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China. The experiment aimed to estimate the influence of three constant temperature degrees (20℃, 25℃and 30℃) on the population growth, damage effects, life cycle and longevity of two stored product mites (Tyrophagus putrescentiae and Aleuroglyphus ovatus) reared on oyster and brown mushrooms, respectively at 80 %R.H. and 14:10 (L:D). The rate of the increase (r) was (0.161 and 0.111), (0.175 and 0.122) and (0.154 and 0.094) at 20,25 and 30 C, when oyster mushroom infested by T. putrescentiae and A. ovatus, respectively. On the brown mushroom, r was (0.167 and 0.126), (0.182 and 0.140) and (0.159 and 0.115) for T. putrescentiae and A. ovatus at 20℃,25℃and 30℃, respectively.The percents of weight loss of oyster and brown mushrooms due to the attack of T. putrescentiae and A. ovatus increased with increasing temperature degrees. The highest decreases in the weight of oyster and brown mushrooms were (18.23% and 24.02%) and were (12.50% and 15.09%) at 25℃in the presence of 320 individuals of T. putrescentiae and A. ovatus, respectively.Immature stages of T. putrescentiae and A. ovatus showed different responses when reared on oyster and brown mushrooms at different constant temperatures. The life cycle for T. putrescentiae and A. ovatus durated 24.47,15.45 and 12.32 days, and 32.64,23.15 and 16.10 days at 20℃,25℃and 30℃, respectively on the oyster mushroom. At 20℃, 25℃and 30℃, the life cycle on the brown mushroom was 20.64,13.90 and 9.26 days for T. putrescentiae, and was 25.21,18.44,11.65 days for A ovatus, respectively.The longevity of T. putrescentiae varied from 34.74 days at 20℃to 23.17 and 17.55 days at 25℃and 30℃, respectively as a result of its feeding on the oyster mushroom. The longevity of T. putrescentiae on the brown mushroom and ranged from 38.37 days at 20℃to 26.00 and 30.38 days at 25℃and 30℃, respectively. The longevity of A. ovatus on the oyster mushroom was 45.34,31.16 and 24.44 days, while it was 48.18,33.90 and 28.40 days on the brown mushroom at 20℃,25℃and 30℃, respectively. Net reproductive rate (R0), population doubling time (PDT) and Mean generation time (T) for T. putrescentiae and A. ovatus affected negatively as temperatures increased. In contrast, both intrinsic rate of increase (rm) and Finite rate of increase (λ) increased as results of temperatures decreased. The values of Ro for T. putrescentiae and A. ovatus was (86.52,52.74 and 20.90) and (42.65,25.72 and 10.36) on the oyster mushroom, while it was (120.87,80.48 and 50.21) and (69.01,48.19 and 16.76) on the brown mushroom at 20℃,25℃and 30℃, respectively. The highest rm for T. putrescentiae (0.265 and 0.301) and A. ovatus (0.140 and 0.189) on the oyster and brown mushrooms were noticed at 25℃. Conversely, the lowest rm for T. putrescentiae (0.171 and 0.195) and A. ovatus (0.09 and 0.112) on the oyster and brown mushrooms were recorded at 20℃.The development of A. swirskii on T. putrescentiae on both oyster and brown mushroom was faster than on A. ovatus. When A. swirskii reared on T. putrescentiae, the life cycle was 10.14,7.90 and 5.20 days on the oyster mushroom, and 8.37,5.98 and 4.75 days on the brown mushroom, at 20℃,25℃and 30℃, respectively. Furthermore, the total developmental time for A. swirskii on A. ovatus at 20℃,25℃and 30℃was13.33, 10.31 and 7.71 days on the oyster mushroom and 10.81,8.27 and 6.19 days on the brown mushroom, respectively.The female longevity of A. swirskii was (30.43 and 36.29 days) on T. putrescentiae on the oyster mushroom and brown mushroom at 20℃and it decreased to (23.04 and 28.08 days) at 25℃and to (17.11 and 22.95 days) at 30℃. Decreases from (21.32 and 27.12 days) at 20℃to (16.30 and 19.36 days) at 25℃and to (11.34 and 15.57 days) at 30℃were observed A. swirskii fed on A. ovatus on the oyster and brown mushroom, respectively.The PDT and T were affected negatively with increasing the temperature degrees. In contrast, the rm andλimproved due to the increase of temperature degrees. The Ro of A. swirskii on T. putrescentiae on the oyster was 10.60,13.89 and 9.71, and 12.48,18.97 and 11.30 on the brown mushroom at 20℃,25℃and 30℃, respectively. R0 was 8.47, 12.00 and 7.12 on the oyster mushroom, and 9.76,14.31 and 8.51 on the brown mushroom at 20℃,25℃and 30℃, respectively, when A. swirskii attacked A. ovatus. Increases in rm of A. swirskii ranged from 0.079 to 0.190 and from 0.096 to 0.224 on T. putrescentiae on the oyster and brown mushrooms, respectively. In the case of A. swirskii on A. ovatus, the values of rm increased from 0.061 to 0.135 on the oyster mushroom and enhanced from 0.074 to 1.63 on the brown mushroom.The results showed that T. putrescentiae was affected by A. swirskii than A. ovatus. The reduction percentages of T. putrescentiae or A. ovatus due to the attack of A. swirskii on the brown mushroom were higher than on the oyster mushroom. The highest reduction percentages for T. putrescentiae (73.90%) and (80.82%) on the oyster and brown mushrooms, respectively were noticed at 25 C and when the ration between the predator:pray ration was 1:10. On the other hand, the highest decreases percentages for A. ovatus (65.21%) and (73.80%) on the oyster and brown mushrooms, respectively were also obtained at 25 C and when the ration between the predator:pray ration was 1: 10. |
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