| The tea green leafhopper,Empoasca vitis G?the,is one of the dominant insect pests in the tea plantations in the mainland in China,which has the high population density,great reproductive capacity,pierce and suck the sap of the tender shoots,and oviposits under thestem epidermis.The research on the insect ethology play an important role in opening up new ways to pest control.Simultaniously,thepeople have payed more and more attention to non-pollution control by means of the sexual pheromones.In the dissertation,the sexual behavior(including emergence rhytem)and the main metabolic substances(including glycogen,trehalose,fat and protein)of the leafhopper were investigated to clear and definite its reproductive strategy.Extract both odor of the overhead female adults in the prosperous mating period and the soaking resolution of their body,whose attracting effect on the male adults was evaluated in the tea plantations and whose chemical composition was inquired preliminarily.The main results were as follow:(1)Observation of the sexual behavior of E.vitis: Its sexual behavior were observed under laboratory conditions.The results revealed that:(1)The eclosion peak was found to appear within the first 3 hour of photophase,and the eclosion rate accounted for 81.44% of the whole day.No eclosion was found during the last 4 hour of photophase and in the scotophase.(2)The early stage of the courtship was defined as the period from male and female eclosion to their first interaction,following with the courtship stage,mating stage and the stage after mating.The duration of the courtship stage,mating stage and the stage after mating were 46.30±1.93 min,85.33±3.24 min,1.63±0.27 min,respectively.And the peak of mating stage was appearing at 5:00-6:00 and 19:00-22:00.(3)The percentage of adults that mated were 60.0%?93.8%?90.9%?57.7% and63.6%,when the sex ratio set with 1:1,2:1,3:1,2:1 and 3:1,respectively.The duration of early stage of the courtship,courtship stage and mating stage of the2:1 dispose were significantly longer than that of 1:1 and 1:2,however,the stage after mating was significantly shorter than that of 1:2.(4)The lifespan of virgin females,virgin males,copulated female,copulated male were 31.4±2.1 d,27.2±2.0 d,22.9±1.2 d and 12.4±0.5 d,respectively,which indicated that mating behavior but not the sex ratio was contributed to the lifespan of E.vitis.(5)26?was the most comfortable temperature for mating of E.vitis,while no mating was found when the temperature was below 22? or above 30?.(2)Video trajectory analysis of mating-induced difference on male and female leafhoppers search for tea fresh leaf and the color cards: The searching behaviour of the tea green leafhopper for the tea fresh leaf and the color cards in yellow,white and green was investigated by the video trajectory analysis instrument,based on Etho Vision XT 11.5 software.The results showed that:(1)It took much time for virgin females to move from the realeasing point to the test leaf edge slowly,and they mostly moved around out of the experimental leaf,while the copulated females move from the realeasing point to the accordingly,its status was called “mania”,“activity” and “still”;respectively;after copulated,the mania duration of both female and male significantly lengthened,especially male.(2)On the yellow card,virgin or copulated females spent much test leaf edge soon,and mainly moved on the leaf;(3)virgin males fast detected the leaf from the releasing point,whose trajectory was very long and complicated and mostly on the leaf,and the copulated male slightly slowed down its speed,mostly searched around out of the leaf;(4)If stimulated,the tested leafhopper would opened out the wings,when its area of body and wings surpassed the normal that of body and wings more than 60%,between 20% and 60 % and less than 20%,more time than virgin or copulated males did;however,on the green card,virgin or copulated males searched even more time than virgin or copulated females did;(5)After copulated,within yellow card area both emerging frequency and searching time of females slightly rose within yellow card area but significantly drew within green card area;correspondingly,both emerging frequency and searching time of males significantly reduced within yellow and green cards.(3)Effect of mating behavior on the main metabolic substances in the body of tea green leafhopper: The effect of mating behavior on the main metabolic substances was investigated,through detecting the content of glycogen,trehalose,fat and protein.And the result showed that the content of glycogen of copulated female reduced by 40.8% and the content of fat rose by53.6 %,compared with non-copulated female;compared with non-copulatedmale,the content of glycogen of copulated male reduced by 22.8 %,the content of protein reduced by 50.5 %,and the content of trehalose increased by 51.8%,moreover,the difference between the both content reached the level of P<0.05 except for trehalose.(4)Extraction of relative pheromones of female adults of the tea green leafhopper and its attractivity to male adults in tea plantations:(1)More males(11.8±1.09)were trapped compare to females(4.3±0.37)when 10 female adults were put in the trap.On the contrary,more females(7.1±0.64)were trapped compare to males(4.2±0.59)when 10 male adults were in the trap.(2)The triangle trap with female adults attracted more males than females,but there was no significant difference when putting male adults in the trap.(3)White triangle trap with extractive of E.vitis inside was used in early September,2015.Infochemicals extract from 5 g tea shoot and 100 female adults attracted more males than that from 5 g tea shoot,5 g tea shoot and 300 female adults extraction for 48 h or 400 female adults lixivium.(4)The same results were got in late November,2015 when we improved the experiment process.(5)25substances were identified from the extractive of E.vitis using GC-MS.And the ocimene was origin from tea plant compare to the blank control(tea shoot).In conclusion,the eclosion peak of E.vitis was found to appear within the first 3 hour of photophase,and the peak of mating stage emerged at 5:00-6:00and 19:00-22:00.Mating has an effect on the searching behavior of E.vitis,male adults preferred for green cards while female adults,for yellow cards.The copulation consumed their main metabolic substances,which seem to cut down the adult lifespan of E.vitis.The field test proved both live females and males respectively attracted the opposite sex in tea field.Through the field test of the odor or soaking resolution of female adults attracting leafhoppers,we considered that the certain substances in body of leafhoppers appealed to the males.Finally,twenty-five components from the odor were identificated,and the ferther research is need to detect which occupied attraction to the male. |
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