Life tables of Tetranychus urticae at different temperatures and the control efficacy of Orius strigicollis

• Main Authors: Yung-Hsiang Lin, 林雍翔
• Other Authors: 段淑人
• Format: Others
• Language: en_US
• Published: 2014
• Online Access: http://ndltd.ncl.edu.tw/handle/20518354635871888923

碩士 === 國立中興大學 === 昆蟲學系所 === 102 === Tetranychus urticae, two-spotted spider mite, is a worldwide pest of many economic crops. It has short generation time and high fecundity to make it outbreak frequently. T. urticae features its reproductive way in arrhenotoky rather than normally zoogamy which is an important evolutionary advantage to disperse and building population. It is the first time to compare the population parameters of these two cohorts with different reproductive ways based on the age-stage, two-sex life table theory at different temperatures. There were significant differences in each preadult stage and the longevity of the adult at different temperatures. However, the means of the developmental duration for each preadult stage and the longevity of the adult of T. urticae in zoogamy cohort were not significantly different from those of arrhenotoky reproductive cohort at the same temperature. The intrinsic rate of increase (r) of 18 and 32oC is 0.1011 and 0.2800 day-1. The finite rate of increase (λ) of 18 and 32oC is 1.1064 and 1.3233 day-1. The net reproductive rate (R0) of 18 and 32oC is 21.6 and 12.1 eggs, respectively. The results of this study demonstrated the differences of population characteristics and parameters between zoogamy and arrhenotoky population at different temperatures. However, arrhenotokous cohort does not show the stable age distribution and that ignores the male offspring produced by virgin females before oedipal mating. Therefore, the population parameters were evaluated in a wrong way. Orius strigicollis has high searching ability and consumption rate. Control efficacies of O. strigicollis against T. urticae on the runner bean (Phaseolus coccineus) in greenhouse and on strawberry (Fragaria ananassa) in semi-field showed that this predacious bug performed well at high release rate. Five pair of O. strigicollis per 40 runner bean plants could inhibit the population growth of T. urticae on strawberry as well as at 12 adults per plant in semi-field. There are basic information, thus can be used in the further study or can be applied to the pest control program. Keywords: Tetranychus urticae, age-stage, two-sex life table, arrhenotoky, temperature, Orius strigicollis, biological control