| Anoplophora glabripennis belongs to the Coleoptera,Cerambycida,Lamiinae,Anoplophora.One of the important forest wormwood pest in China,distributing in many provinces of China wildly.It has been listed in the national forestry dangerous pests list for harming farmland forest,shelter forest,green belt and other commonly used tree species intensively.Acer rubrum classifies by the plant classification system APG IV belongs to the Sapindaceae,Acer.It’s also famous for the Northern Maple,the Swamp Maple,and the Canadian Maple,which has been uesed as classic border tree in European and American wildly for the ornamental value until now.A large number of Acer rubrum has been introduced as afforestation tree species planted in the urban gardens,roads and parks in order to improve the landscape benefit.Acer rubrum has been harmed by the anoplophora glabripennis increasingly since its introduction in central Guizhou,the leaves of the affected plants turn red and fall off in advance.According to field investigation of damage degree,occurrence characteristics regularity and regularity of Anoplophora glabripennis on acer rubrum,contacts the investigation results of pest index,stand structure index such as vertical canopy density,herb and shrub coverage,plant configuration,spatial distribution pattern of resistant plants to analyze the harm regularity and selection tendency of Anoplophora glabripennis to Acer rubrum in this sthdy.Determines the VOCs of Acer rubrum by headspace adsorption.Screens out the VOCs of Acer rubrum which affected the host plants selection of Anoplophra glabripennis through the olfactory experiment of Y-type olfactory instrument.Finds out the preference relation between Anoplophra glabripennis and Acer rubrum,screenis the VOCs of Acer rubrum that have obvious evasive and attractant effects on Anoplophra glabripennis in order to provide research basis for green control and attractant development of Anoplophra glabripennis.The main research results of this study are as follows:(1)The degree of harm to Acer rubrum caused by Anoplophra glabripennisInvestigated the plants configuration mode,distribution patterns of resistant plants,caculted the vertical canopy density,herb and shrub coverage as while within a 100 m radius around Acer rubrum,the results are as follows: 6 kind of spatial distribution patterns of Anoplophra glabripennis resistant plants have been find in sample plots,the highest number of plant species is58,the lowest number is 17.The scope of vertical canopy density within 5.8%-22.2%,the scope of herb coverage within 2.5%-3.1%,the scope of shrub coverage within 2.5%-4.1%.Combines the the damage rate of Anoplophra glabripennis,the results shows that the harm degree of Anoplophra glabripennis is plants influenced by plants configuration modeaffecting the stability of plant community,resistance to pests and diseases,which shows different targets of plant community species diversity,vertical canopy density,herb and shrub coverage,and distribution pattern of resistant plants.It means that the higher the diversity level is,the lower the risk rate is,the lowest is only 20%.As the same level of plant community species diversity and same configuration mode vertical canopy density,the higher herb,shrub coverage is,the lower damage rate is.Whit the similar value of vertical canopy density,herb and shrub coverage,the damage rate is increased for a high proportion of sensitive tree species and a small diffusion range of Anoplophra glabripennis causes by the unreasonable location distribution of resistant tree species.(2)The regularity of outbreak of Anoplophra glabripennis to Acer rubrumThe isometric sampling method was used to investigate the damage status of Anoplophra glabripennis to Acer rubrum,recorded the parameter changes were recorded every 15 days,the results are as follows: Anoplophra glabripennis only has one generation to Acer rubrum,the overwintering larvae became active in late April,pupated in late May,emerged in early July,and stopped encroachment on Acer rubrum in mid-October.The damage rate of the sample plots was47%,which has be widespread and uncurbed.The average number of investigated plants was 887,and the average number of affected plants was 376,the highest damage rate is 89%,the lowest is20%.With the increase of tree age and DBH,the spawning sites begin to move up along the trunk,and the damage at branching gradually increases progressively.Egg-laying grooves mainly distribute in the trunk,fork and main tip mainly,among which the fork is the most,rates66.1%-79.6%,The main stem or main tip comes next,rates 14.4%-24.6%,the tip distribution is minimal,the lowest is 0.The control methods are mainly aimed at chemical control of adult insects during their emergence currently,the inefficient overall control effect is caused by the deficiency of controlling measure in different puberty of Anoplophra glabripennis.(3)Changes of the VOCs of Acer rubrum induced by insect pests Dynamic headspace adsorption and GC-MS were used to collect and analyze the constituents and contents of the VOCs of healthy and pest branches infestation of Anoplophra glabripennis of Acer rubrum,the results are as follows: Acer rubrum has 60 VOCs consist of seven categories which inlude alcohols、erpenoids,hydrocarbons,aldehydes,ketones,esters and amides.Hydrocarbons reach the highest content around 53.45 %.There are 59 VOCs of undamaged branches and 58 VOCs of pest branches.The contents of alcohols,aldehydes and hydrocarbons VOCs of the pest branches change significantly compared with the undamaged branches of Acer rubrum,Among the total substances,the content of 4 compounds increased,and the relative percentage of increased content from low to high is:(3Z)-3-Hexena < 2-hexanone < Cis-3-hexenal <cis-3-hexenyl acetate.The content of 7 substances decreased,and the relative percentage of the decrease from low to high is: Neral< Heptyl acetate< trans-2-hexene-1-ol< 2-tskone< E)-acetate-2-hexene-1-ol<(3E)-4,48-Dimethyl-1,3,7-nonatriene< trans-2-hexenal.The results of cluster analysis shows that the pest induced significant changes in the VOCs of Acer rubrum.The VOCs of pest branches clusters the similar space,shows the differentiation with undamaged branches.The results of literature comparison show that hydrocarbons and terpenoids are common VOCs between Acer rubrum and the host plants,α-pinene,trans-2-hexenal,nonaldehyde,camphene,phyllyl acetate,cis-3-hexenol,and laurene are common compounds in the host plants of Anoplophra glabripennis,and the contents of VOCs are different among different tree species.(E)-acetic acid-2-hexene-1-alcohol ester,(3 E)-4,8-dimethyl,3,7nonyl-1-3 unique to Acer rubrum.(4)Olfactory behavior responses of Anoplophra glabripennis to 10 VOCs of Acer rubrumTen main compounds with significant changes in the content of VOCs of the affected Acer rubrum were selected,and the olfactory behavior responses of Anoplophra glabripennis to five concentration gradients of 10 VOCs were measured by a "Y" type olfactory apparatus,the results are as follows: 0.01 、 0.1 、 1 、 10 /μL/μL concentration of the VOCs of cis-3-Hexen-1-ol,cis-3-hexenyl acetate,α-pinene,nonanal have obvious attraction effect on both male and female Anoplophra glabripennis.0.1、1、10 /μL/μL concentration of the VOCs of trans-2-Hexen-1-ol,acetate,(E)-2-Hexen-1-ol,ocimene,(3E)-4,48-Dimethyl-1,3,7-nonatriene,Camphene,(3Z)-3-Hexenal,have obvious evasive action on both male and female Anoplophra glabripennis.Within the test concentration range,the reaction tendency of male and female to the same VOC is basically the same,but the olfactory behavioral response intensity,attraction rate and avoidance rate of female and male do not increase with the increase of concentration.Both different concentrations and of same concentration of VOCs have different attractant and avoidant rates to female and male Anoplophra glabripennis. |
PDF Full Text Request