Life table parameters of Phytoseius plumifer (Phytoseiidae) fed on two-spotted spider mite at different constant temperatures

摘要

The life table parameters of Phytoseius plumifer Canestrini & Fanzago fed on corn pollen and nymphal stages of Tetranychus urticae Koch were determined at eight constant temperatures (10, 15, 20, 25, 27, 30, 35 and 40 +/- 1 degrees C), 50 +/- 5% relative humidity and a photoperiod of 16:8 h (L:D). Fifty 1-day-old eggs of P. plumifer were kept individually in a growth chamber at each temperature and all events were recorded daily for all immature and adult stages. Adult female longevity decreased from 73.42 days at 15 degrees C to 34.73 days at 35 degrees C. The net reproductive rate (R-0) increased with increasing temperature from 15 degrees C (8.70 females/female) to 27 degrees C (29.6 females/female) and then decreased noticeably. The values of the intrinsic rate of increase (r(m)) and finite rate of increase (lambda) were recorded to be highest at 30 degrees C (0.257 day(-1) and 1.29 day(-1), respectively), which decreased at 35 degrees C (0.244 day(-1) and 1.28 day(-1), respectively). The mean generation time (T) decreased significantly with increasing temperature from 15 degrees C (48.75 days) to 35 degrees C (11.02 days). The shortest doubling time (DT) was observed at 30 degrees C (2.69 days). The highest and lowest values of total fecundity were obtained at 25 degrees C (49.10 eggs/female) and 35 degrees C (19.71 eggs/female), respectively. Our findings revealed that the examined population of P. plumifer can develop and reproduce under a wide range of temperatures (15-35 degrees C), but its potential for control of two-spotted spider mite in the field has yet to be determined.