Effects Of Interplanting Grass On Arthropod Community Diversity In Citrus Orchard

This paper has dealt with the impacts of diversity to intercropping aromatic plants andforage grass in citrus orchard.6test treatments were designed, including planting Ocimumbasilicum, Ageratum conyzoides, Lolium perenne, Cichorium intybus, natural grass andclean tillage as the control.The characteristics of variation of precipitation time series ofdiversity composition species richness, index of diversity, uniformity and dominance indexof arthropod community, the pest sub-community and natural enemy sub-community in thedifferent intercropping plots were assessed and analyzed.The investigating results of arthropods under the conditions of intercropping aromaticplants and forage grass in citrus orchard were shown as fallow:(1)The proportion of the arthropods in various communities was affected by various grassintercropping, such as the proportion of insects of the order Hemiptera in different testplots were respectively, Ocimum basilicum22.89%, Ageratum conyzoides21.69%,Lolium perenne22.99%, Cichorium intybus23.33%, natural grass23.33%, and CK ofclean tillage25.64%.(2)The proportion of predators and pest arthropods have been affected by grassintercropping significantly, it shown as follow, Ocimum basilicum1:1.67, Ageratumconyzoides1:1.97, Lolium perenne1:2.33, Cichorium intybus1:2.58, natural grass1:3.00,and CK clean tillage1:6.15.(3)There was a definite differenty on the total diversity index of arthropod community invirous grass intercropping, Ocimum basilicum3.52, Ageratum conyzoides3.56, Loliumperenne3.26, Cichorium intybus3.37, natural grass3.31, CK clean tillage3.18.(4)The dominant insect populations belonged to the order Hemipetra and Acarina.(5)As the season change and alternation,the species richness, index diversity,uniformity and dominance index of arthropod community presented all kinds of variationtendency in6experimental treatments. ascending to relatively stable to slowly declining,the trend of evenness index was These variation tendencies behaved differently in differentaromatic plants,forage grasses test plots and various periods in citrus orchard.The diversity index of pest and natural enemy sub-community presented differentcharacteristic precipitation time series in different periods. The diversity characteristic ofnatural enemy fallowed the pest sub-community variation. The various intercroppingmeasures influenced the species quantity of arthropod community observably. Thecommunity composition and diversity dynamic response of arthropod community, pest sub-community and natural enemy sub-community were changed by intercropping the2aromatic plants Ocimum basilicum, Ageratum conyzoides and2forage grass Loliumperenne, Cichorium intybus these transforms were helpful to ecological control of pest.