| Grape phylloxera,Daktulosphaira vitifoliae(Fitch),is an aphid-like pest,native to eastern North America but nowadays it is widely regarded as the most destructive insect pest of commercial grapevines Vitis worldwide.Now,the rooting-zone restriction technology has matured,root confinement can help to achieve the management to the environment of rooting-zone,however,the effect of organic material to soil condition and grape phylloxera remains unclear.Meanwhile,our previous study showed that intercropping of A.bidentata and grapevines can be used to control grape phylloxera,and ?-ecdysterone is the main bioactive component,However,the sublethal effects of ?-ecdysterone to grape phylloxera is still unknown.In this study,we assessed the sublethal effects of ?-ecdysterone to grape phylloxera,and explored the effect and mechanism to grape phylloxera by the application of organic material.The main results were summarized as follows.we assessed the sublethal effects of LC10,LC20 and LC40 of ?-ecdysterone on grape phylloxera.The adult developmental periods and total life span were significantly decreased by LC40 of ?-ecdysterone(15.23 d and 37.75 d)than control(27.50 d and 50.11 d).Fecundity significantly lower than control(219.98)when grape phylloxera were exposed to LC20(185.32)and LC40(111.18)of ?-ecdysterone.The vitro assays and potted experiments of various organic materials showed different effects to grape phylloxera.In vitro assays of various organic materials,Adult developmental periods were significantly prolonged by oil-tea-cake organic fertilizer(27.24 d),pig manure(27.74 d),cow dung(25.91 d),chicken manure(27.84 d),bio-organic fertilizer(25.68 d),green manure(26.17 d),tobacco stems organic fertilizer(24.85 d)compared with control(20.78 d),phylloxera fecundity was significantly increased by oil-tea-cake organic fertilizer(247.46),pig manure(217.00),cow dung(217.47),chicken manure(208.78),bio-organic fertilizer(205.53)and green manure(181.71)compared with control(162.21).Potted experiments showed that the nymphs and adults were significantly increased by oil-tea-cake organic fertilizer.The number of eggs,nymphs and adults significantly lower when treated by pig manure(53.07?165.64?77.33),cow dung(22?86.87?12.6),chicken manure(5.27?43.13?16.87)and green manure(46.61?80.22?10.94)compared with control(328.71?216.96?155.29).In vitro assays of different nitrogen levels,the treatment of 60mg/L decreased the nymphs developmental periods,increased the adult developmental periods,longevity and fecundity.The intrinsic rate of increase(0.18)and the finite rate of increase(1.20)of 60mg/L significantly higher than the treatment of 15mg/L(0.12 and 1.12).In vitro assays of different calcium levels,the longevity and fecundity were significantly decreased by no calcium(33.60 d and 66.58)and low calcium(34.12 d and 64.73)treatments compared with the normal calcium levels(40.21 d and 222.52).The intrinsic rate of increase(rm)and the finite rate of increase(?)and the net reproductive rate(R0)decreased by no calcium and low calcium treatments.The results showed that ?-ecdysterone which produced by intercropping crop,still can reduce the population of grape phylloxera at the low concentrations;Soil environment formed by various organic materials showed different effects to grape phylloxera,oil-tea-cake organic fertilizer is beneficial to grape phylloxera and chicken manure etc.are harmful to them;The control of grape phylloxera by regulating nutrition is not feasible.Our work will enhance our understanding of the effects and the impact mechanism of various organic materials to grape phylloxera,and the promotion it's control by ecological regulation of root zone. |
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