The Research Of Biology And Hazard Characteristics Of Brevipalpus Lewisi McGregor

The research studied Brevipalpus lewisi McGregor's biological characteristics, hazard characteristics and growth duration by field survey and indoor rearing; determined Metasequoia glyptostroboides's nutrition indicators by the method of plant physiological; use the technique of Headspace SPEM-GC-MS to determine the changes in volatile compounds of Metasequoia glyptostroboides before and after damage, to understand hazard characteristics of Brevipalpus lewisi McGregor more ; choose several high efficient and low virulence pesticide to determine the indoor pesticide toxicity and outdoor efficacy of Brevipalpus lewisi McGregor, to apply the scientific basis for practical application.The main findings are as follows:1. The hole generation of Brevipalpus lewisi McGregor go through egg,larvae mites, teliochrysalis and adult period, there is a quiescent between each mites state since larvae mites. The adult mite is red or dark red, oblong, 4 pairs of feet; the teliochrysalis's form looks the same to the adult, it's light in color than the adult, 4 pairs of feet; the larvae looks bright red, 3 pairs of feet; the egg is oval, bright red and shiny.2. Brevipalpus lewisi McGregor taking juice in the back of Metasequoia leaves at adult, teliochrysalis and larvae.The injured Metasequoia glyptostroboides always looks brown.This mite has obvious heterogenesis phenomenon, every mite states often injure together.3. The hole generation thermal threshold of Brevipalpus lewisi McGregor is 14.35℃, the total effective temperature is 287.74 day-degree. The developomental period of Brevipalpus lewisi McGregor is 66.67d at 18℃;46.67d at 21℃; 31.0d at 24℃; 23.0d at 27℃;it is only 18d when the temperature is 30℃.4. After the injure of Brevipalpus lewisi McGregor , Metasequoia leaves'chlorophyll content has reduced 18.5%, the soluble sugar content has reduced 12.8%, the free amino acids has reduced 12.2%, the flavonoids content increased 26.6%, tannic content has increased 25.8%, the active of peroxidase has increased 65%, the active of superoxide dismutase has increased 139%.It shows that the physiological index has changed when Metasequoia has been infested.5. After Metasequoia is infested, the relative content of volatile compounds in leaves changes obviously. As the main components, the relative content of caryophyllene has been decreased from 39.4% to 27.33%, while the relative content of 1R-α-pinene has been increased from 35.67% to 50.27%. moreover, new volatile compounds have been generated. 6. Virulence indoor tests of several pesticides to Brevipalpus lewisi McGregor show that, the median lethal concentration of Avermectin ? profenofos is the lowest as 0.57241mg/L; the result of outdoor pesticide effect reveals that, the control effect of Avermectin ? profenofos is the best, which is up to 97.70%, 99.14% and 99.55% separately after 1 d, 2 d and 3d.