| The advance on arthropod community was systemically reviewed in the thesis.The summary of arthropod community,utilizes of natural enemies and relationship between pests and plants in orchards were summed up.According to the investigation,field and indoor trial in ecology,structure and diversity of arthropod community,population dynamic,control function,effect of chemic substance and relationship between pests and plants in plum orchard,by using knowledge and technique of ecology,statistics,taxonomy and chemic identification and analysis etc,the results were as follows:1.The structure and dynamics of the arthropod community in plum orchard was investigated,identified,classified and analyzed in 2006 in plum orchard of Anhui Science and Technology University and horticulture of Fengyang County.169 species belonged to 4 classes,18 orders and 90 families were discovered in the plum orchards.According to nutritional and feeding relationship,the arthropod community was divided into 4 sub-communities and 6 functional groups;the relative abundance of the 4 sub-communities was respectively 41.62%of phytophages,47.20%of predators,7.59%of parasitoids and 18.7%of neutralities of arthropods.Dominant species of phytophages were D.koreanus Borchsenius;of natural enemies were C.rubidus Hope and spiders in plum orchards.By the analysis of number dynamics,ecological dominance and diversity of the functional groups,the results showed that the structure of arthropod communities in the plum orchards was relatively stable.It was obvious that natural enemies were able to control pests effectively.2.Spatial pattern and time-series dynamics of Didesmococcus koreanus Brochseniusenius and Chilocorus rubidus Hope were analyzed by calculating five indices of aggregation,and parameters of Iwao model and Taylor's power law model form March to September.The results showed that the spatial pattern of D.koreanus Brochsenius in horizontal and upright dimension,at different direction,altitude and population density in plum orchard belonged to an aggregated distribution pattern,and the fundamental component was the group composed of several individual and the individual was aggregated.The Aggregation intensity of D.koreanus Brochsenius was the highest in upper and southern part of crown,and the lowest in its lower and northern part.The aggregation was due to the biological habits of D.koreanus Brochsenius and environmental heterogeneity.No mater D.koreanus Brochsenius was in the upper,middle, or lower crown of plum tree,its aggregation intensity was higher before mid-ten days of April,and then gradually decreased after the last ten days of April because of preying of natural enemies and so on C.rubidus Hope.Based on the data of the spatial distribution, the model of the most suitable sampling quantity is established and the suitable sampling quantity at different density of D.koreanus Brochsenius and error level is presented.The sequential sampling diagram was drawn to investigate the D.koreanus Brochsenius population levels in plum orchard.The pattern of C.rubidus Hope in plum orchard fitted the aggregated distribution pattern,and the aggregation of it was due to environmental effects.Meanwhile,the spatial pattern and correlation of D.koreanus Brochsenius and C. rubidus Hope in different periods were investigated with Geostatistics.The results showed that the semivariogram of D.koreanus Brochsenius and C.rubidus Hope could be described by spherical model,indicating that their spatial pattern were in agreement.The spatial variation was aroused by its spatial autocorrelation in small scales,and the spatial pattern had no apparent changes in different periods.The range varied from 9.56-15.70 m and from 18.83-19.74 m,respectively.The amount and spatial distribution of C.rubidus Hope was closely related to that D.koreanus Brochsenius,which revealed that C.rubidus Hope was the dominant natural enemy of D.koreanus Brochsenius.3.The structure and relative abundance of ladybugs sub-community of plum orchard were carried out,after primarily classification and authenticating in laboratory.There were 68 species belong to 48 geneses,15 families.The dominant species were Chilocorus rubidus Hope,Chilocorus kuwanae Silvestri,Harmonia axyridis,Coccinella septempunctata Linnaeus,Progylaea japonica and Stethorus punrtillum Weise.Changes of time pattern of the species richness(SR),total individual number(N),index of diversity (H′),and evenness(J) were preliminarily studied by using multiple early and medium-term of growth of stepwise regression analysis.The results showed that in plum tree,where the main factor affecting ladybugs was evenness and in lopper it was the species richness.Calculation the diversity of result of spatial pattern for time,space and three dimensions(time-vertical and level space) showed that the spatial pattern of ladybugs in plum orchard all belonged to aggregated distributions.4.The study of neutral insect sub-community was carried out.It was showed that neutral insect whose relative abundance was more than 10%was one of important parts and played an undoubtedly role in the arthropod community of plum orchards of Anhui science and technology university and horticulture of Fengyang county form March to November month in 2007.Meanwhile,the occurrence tendency of the neutral insect which accompanied with the occurrence of natural enemy was somewhat earlier than the dominant pest,which could,to some extent,make up with the defect of natural enemies who take place always behind the pests in the natural situation.The study on time niche among natural enemies and neutral insects showed that encounter opportunity of natural enemies to Chilocorus rubidus Hope,Chilocorus kuwanae Silvestri,Harmonia axyridis, Coccinella septempunctata Linnaeus,Progylaea japonica and Stethorus punrtillum Weise in time sequences were larger.And that is to say,the neutral insect has active effect to maintain the population of natural enemies in the plum orchard.The principal component analysis was used to explore the neural insect's function in the community,a conclusion was drawn that predominant effect of neutral insects was more scattered and they played the role by the functional group.Through the calculation of grey correlation analysis of natural enemy's effect to mixed neutral insect population,it was showed that the sequence of grey relational grade was as follow:Chilocorus rubidus Hope＞Harmonia axyridis＞Erigonidiurn graminicola.5.Disturbed by Chlorpyrifos,Supracid and Abamectins,the composition and structure of arthropod community were systematic investigated and analyzed at representative sampling sites.And the results showed that application Chlorpyrifos and Supracid caused some phytophagous species and dominant index of arthropod community becoming abundant observably in plum orchard.Species diversity of general community was decreased significantly.The numbers of species in community were decreased remarkably.Specially,species in the categories of Araneae,Hymenoptera,Coleoptera and Diptera,or functional groups of predators,parasitoids and neutrals were reduced. Therefore,the potential impacts of the phytophagous natural enemies of predators and parasitoids weakened in category and individual.To some extent,this might lead to outbreak of the phytophagous in the plum leaves.The compared with plot of Abamectins and no being control was not significant difference.So indiscriminate application of Chlorpyrifos and Supracid should be prohibited in integrated pest management(IPM). Consequently,it is advisable that an ecological pest management(EPM) program be implemented with Abamectins insecticides and horticulture measure.The arthropod community was divided into four sub-communities:pests,predatory,parasitoids and neutralities by the standard of nutrition and hunting.The differences of the diversity, abundance,evenness and structures of arthropod community and sub-community in plum orchard among treatments Gramoxone,Simazine and contrast(CK) were analyzed by using a number of community parameters.The results showed that the diversity and evenness index of arthropod community and four sub-communities were low in herbicide plots,while the dominant concentration was high,the arthropod community stability was lower than the contrast,and the pest out break was more possible in herbicide treatments than that in the contrast.6.By the method of OECD(Organization for Economic Co-operation and Development,OECD) filter paper contact firstly,the effects of five rare earth elements on soil fauna community structure and their ecological toxicity to Holotrichis parallels in Plum Orchard were studied.The results showed that there were significant differences between treatments and the control in soil fauna species,quantity of main species,diversity index,evenness index,Dominant centralization,ecological dominant index,species richness and function group.Urgent and chronic toxic test showed that the differences between the treatments and the control were significant.Toxicity order of five rare earth elements were La＞Ce＞Pr＞Nd＞Sm,but their toxicity response were Different.The growth of Holotrichis parallels and its pupae were stimulated by all the rare earth elements in 14 d,and weight of Holotrichis parallels and its pupae were increased obviously;28 d after the Nd and Sm convert the stimulating effect into inhibition,the stimulating of La and Ce were weakened,and the stimulating of Pr were enhanced.Rare earth elements could change the structure of the soil fauna,and the soil fauna had a certain eco-toxicity.7.The structure of weed communities in plum orchards of Anhui science and Technology University and horticulture of Fengyang County which many arthropods dwelled was studied,and there were 97 species belonged to 28 families.The temporal dynamics of individual number,species abundance and diversity of both weed and arthropod communities were dealt with,and it was also analyzed that the arthropod communities characteristics index were affected by the corresponding index of weed communities,and the change trend of the first and second dominant species both weed and arthropod communities in all of two kinds of plum orchards were similar.The cluster analysis indicated that there existed similarity on the time dynamics of weed and arthropod communities in two plum orchards to some extent.8.The arthropods communities in plum orchard were investigated on Space-time dynamic and temporal spatial niche.The results showed that the arthropod community was abundant.The individuals of species,diversity indices,and evenness changes with time. Myzus persicae and Asiaarposina sasokii had the widest spatial niche breadth,while Didesmococus koreauus Borchs had the widest temporal niche breadth.Among the natural enemies Chilocorus rubidus Hope and Didesmococus koreauus Borchs overlapped larger than that of the others,which indicated their synchrony in temporal dimension and their similarity in spatial dimension.As the dominant natural enemies the two populations should be protected and utilized to control plum pest.9.The experiment was conducted to study the functional response,density of predator and prey,and their relationship,mutual interference,space heterogeneity and temperature effects on Chilolocorus rubidus Hope to Didesmococcu koreanus Borchs in the laboratory. The results were showed that the functional response,and effects of mutual interference and temperature on predacious efficiency of Chilocorus rubidus Hope at different larvae and the adult ladybugs were determined as HollingⅡand Hassell equation,x2 test indicated that the theoretical expectation fits the observe values,and the differences were not significantly different(p＜0.05).The searching efficiency decreased with the increase of predator density.The mutual interference among individual predators and preys were more obvious with the increase of their density.There were mutual interference among the larves and adults of the ladybugs,and the predatory rate increased as its density decreased. Predacious efficiency of Chilocorus rubidus Hope was dropped with complexity of space heterogeneity.10.Using field observations and periodic sampling of Chilocorus rulolus Hope and Didesmococcus koreanus Borchs of plum orchard and studing on diets of Chilocorus rulolus Hope in Anhui Science and Technology University in 2005,studies on the bionomics of them showed that all 1 generation developed annually.The adult of C. rulolus Hope oveiwinters in weeds and seams and it is an important natural enemy of D. koreanus Brochsenius.It mainly occurs in peach and plum trees,and suppresses the population of D.koreoaaus Borchs efficiently.Its larvae and adult were the main preyer of the scale insect.The second nymphal stage of D.koreoaaus Borchs over wintered on brush, emerge in March of the next year,from April to May was the adult's stage and begin to hatch among the first ten days of June and mid-July.The D.koreanus Borchs attack trees mainly in forms of fixed nymsphs and adult females.Meanwhile,natural enemies had high capability of control,so it was suggested to adopt integrated pest management.The feeding results of C.rubidus Hope on the five artificial diet indicate that the mixture of grass carp, pig-liver and powder of Noctidae larvae could met basica nutrition requirement of the adult respectively.The adult fed with the mixture had high a survival rate,but the females had a relatively low egg production.Preying functional response of C.rubidus Hope adults on D. koreanus Borchs was fitted to HollingⅡmodel.Adults fed with No.3 and No.5 diets preyed strongly on D.koreanus Borchs.However,from 25 to 290 days,their preying capacities(1-31 head) decreased with raising duration.Food-seeking efficiency of C. rubidus Hope(0.3802-0.0717) declined with increasing the densities of D.koreauus Borchs(2-10 head).A better efficiency was detected in C.rubidus Hope adults fed with No.3 and No.5 diets.Adding Preying stimuli in the adult diet could significantly increase the survival rate from winter,egg number praying ability and searching efficiency.11.By focusing on 8 host plant species including peach,plum,cherry plum,apricot, apple,pear,cherry and hawthorn,we investigated the feeding,oviposition,population dynamics of Didesmococcus koreanus Broth in the field,and the relationship among the selectivity of D.koreanus Borchs,branch physical structure and chemical substance in the hosts and D.koreanus Borchs in laboratory.The fitness of eight host plants to D.koreanus was quantitatively measured with selective index(SI),damage index(DI),and preference index(PI).Moreover,index of population trend(I) was used as an important estimate for the influence of host plants on the natural population of D.koreanus.The results indicated that,under all three types of plant growing conditions,the order of fitness was peach,plum,cherry plum,apricot,apple,pear,cherry and hawthorn.The fitness of 8 host plants,presenting as a normal distribution,were consistently the best in June with a good growing condition～inferior medium growing condition～weak condition pattern.D.koreanus preferred to feed and oviposit on peach,plum,cherry plum and apricot,where they featured higher survival,eclosion and hatched rate and more rapid nymphae increase,and also higher values for other four indexes(SI value＞0.875, PI value＞5.469,I value＞5.75,DI value＞1.049).According to the fitness indexes,the host plants of D.koreanus may be divided into three categories,with peach,plum,cherry plum and apricot as the most suitable hosts,apple,pear and cherry the suitable,and hawthorn the least suitable category.With the best linear regression equation was PI=-0.3389+DI, there was an obvious linear relation between PI,SI and DI(r0.01=0.937).Measuring and scanning showed that there was a significant negative correlated(r0.01=-0.976) between fitness and the epicuticle hair numbers,hair length,epidermis thickness and branch diameter.The feeding and oviposition have been controlled by the physical structure of branches.Compared to the most suitable hosts,the epicuticle hair numbers, hair length,epidermis thickness and branch diameter of hawthorn were,respectively,2.73, 3.27,2.77 and 3.47 times higher.Feeding-selectivity and oviposistion-selectivity of D. koreanus Borchs with the eight hosts of the hairs density,length,epidermis thickness, branches diameter,flavones and tannin,and all reached a very significant negative correlation,and their correlated coefficients r were -0.9413 to -0.8816 and -0.9624 to -0.8943 respectively.The same reasoning,feeding-selectivity and oviposistion-selectivity of D.koreanus Borchs with the eight host plants of branch's soluble sugar,host plant's soluble protein,free amino acids,water content,CarE,ACHE,GSTs and the insect's soluble protein content,and all reached a very significant positive correlation,and their correlated coefficients r were 0.9025 to 0.9413 and 0.8937 to 0.9201 respectively. Feeding-selectivity and oviposistion-selectivity of D.koreanus Borchs is consistent on the eight hosts.Activity of CarE,ACHE,GSTs and the soluble protein content of D.koreanus Borchs that feeding peach,plum,cherry plum and apricot which branches relatively smooth surface,low hair density,length short,thin epidermis,more content of host's soluble proteins,free amino acids,water content,and low content flavones and tannins were relatively high.The D.koreanus Borchs of the host's selectivity strong is serious harm to the eight hosts,these of apple,pear and cherry were inferior,and these of hawthorn were the worst.Above results may provide clues for resistance breeding,forecast and optimal control strategies.12.The effects of Chlorpyrifos,Supraeid and Abameetins on the predation function of predatory ladies group were evaluated with function method.The result showed that all predating functional responses of predatory ladies were in accordance with the HollingⅡmodel by insecticides treatments,but their model parameters were changed.It was obviously lower than controls that in abilities of controlling pest and the searching efficiency of the predators.The mortalities(Dt) and decreasing rates of predation function(FDt) of surviving predatory ladies were different,and their order was Chlorpyrifos,Abamectins and Supracid for big to small.Susceptibilities of predatory ladies to Chlorpyrifos were relatively higher(mean of Dt was 74.64%),on the contrary with the Supracid treatment(mean of Dt was 30%),and Abamectins treatment was medium. Supracid was a relatively more securities pesticide to predatory ladies and its affects were small to lethality and predation function. |
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