| Bemisia tabaci(Gennadius)is an important pest on greenhouse vegetables in Jiangsu Province.In addition to direct damage,it also spreads viral diseases,which seriously affects the safe production of greenhouse vegetables.Due to the short developmental duration and serious generation overlap of B.tabaci,there is currently no specific control pesticide.Indiscriminate use and the abuse of chemical pesticides of farmers in production have led to an increase in the resistance of B.tabaci,which had increased the difficulty in controlling B.tabaci.In this paper,the screened plants that induce and repel Bemisia tabaci were studied,and the volatiles of selected plants were analyzed,and the control effect of the intercropping on B.tabaci was further studied in the field test.Finally,several safe and efficient pesticide were selected to provide new technical means for the ultimate implementation of pollution-free control of B.tabaci.1.The selectivity test of B.tabaci on induce plants showed that there were significant differences in the color selectivity of the eight test plants.Among them,B.tabaci had the highest selection rate for Abutilon theophrasti,which was significantly different from the other 7 vegetables(P<0.05),and it also had,higher selection rate for Mentha haplocalyx and lettuce.The host's selective assay found that B.tabaci had the highest selectivity rate for Mentha haplocalyx,which was significantly different from the other 7 vegetables(P<0.05)and also had higher selectivity rate for Abutilon and the Basil.The olfactory response test showed that B.tabaci had the highest relative selectivity for Mentha,up to 72.7%,followed by Abutilon(70.0%).The selectivity rates of the other vegetables was:Basil(63.60%)>Abelmoschus esculentus(60.00%))=Lettuce(60.00%)>Medicago(54.50%)>Achyranthes bidentata(52.50%)>Leonurus(50.00%).Twenty kinds of volatile substances were identified from the stems and leaves of Mentha haplocalyx by GC/MS analysis in the laboratory,mainly including Benzene methylene,1,3,8-p-menthene,menthol,caryophyllene,[s-(E,E)]-1-methyl-5-methylene-8-(1-methylethyl)-1,6-cyclosebacediene,1,5,5-trimethyl-6-methylene-cyclohexene and other components.2.The selective test of B.tabaci on Non-hobby plants showed that there were significant differences in the color selectivity of the eight tested vegetables.Among them,the selection rate of B.tabaci to celery and amaranth were the lowest,followed by purple jasmine and castor bean,and the selectivity of B.tabaci to the other four vegetables were not significant(P>0.05).The host selective determination of B.tabaci on the 8 plants found that B.tabaci had the lowest selection rate for celery,which was significantly different from other 7 vegetables(P<0.05)and also had a lower selection rate for Chinese chives.The olfactory response test found that among the eight vegetables tested,the relative selectivity of B.tabaci to celery was the weakest,only 14.50%,followed by Chinese chives(23.50%),and the other selected rate for the rest vegetables were:Carrot(48.00%)>Artemisia lavandulaefolia DC(46.50%)= Foeniculum vulgare(46.50%)>Ricinus communis(42.00%)>Mirabilis jalapa(38.00%)>Coriander(32.00%).GC/MS analysis of volatile substances in celery stem and leaves showed that 20 substances were isolated from the volatile substances in celery stem and leaves,mainly were Limonene,Eudesma-4(14),11-diene,?-caryophyllene,a-pinene and the like.2.In order to explore the application technology of hobby plants and low-loving plants in the green prevention and control of vegetable B.tabaci,the control effects of different planting methods of celery and Mentha haplocalyx on the control of Pepper B.tabaci were studied.The results showed that the celery were interplanted in the greenhouse pepper field with density of 3:1 and 5:1,the number of adults of B.tabaci on pepper plants decreased significantly;while the density of 8:1 interplanting did not significantly affect the adults of B.tabaci.At one end of the pepper field,5 rows of Mentha were planted while at the other end,5 rows of celery were planted,after 15 days,the number of adults of B.tabaci on the pepper decreased by more than 29%compared with the control group;5 rows of Mentha were intensive planted at one end of the pepper field,5 rows of celery were interplanted with density of 3:1 and 5:1,and the number of adults of B.tabaci on the pepper plant with celery interplanted with density of 3:1 and 5:1 decreased by 38.57%and 25.71%compared with the control group after 15 days.The results showed that celery had a good repellent effect on Bemisia tabaci;interplanting Mentha on one end of the greenhouse while interplanting celery among pepper plants,could further improve the repellent effect on Bemisia tabaci.3.The effects of six kinds of pesticides such as 19%Cyanamide bromide suspension agent,10%cyanamide bromide suspension agent,80%ene pyridine pyridone water dispersible granules,50%nitenpyram soluble granules,50%Water dispersing granule of fluridinitrilea and 40%chlorfenidil and thiamethoxam water-dispersible granules on nymphs and adults of Bemisia tabaci were studied.The results of the laboratory virulence test showed that the LC50 value of virulence(active component)of 19%Cyanamide bromide suspension agent,10%Cyanamide bromide suspension agent,80%ene pyridine pyridone water dispersible granules,50%nitenpyram soluble granules,50 Water dispersing granule of fluridinitrilea and 40%chlorfenidil and thiamethoxam water-dispersible granules on the nymphs of Bemisia tabaci were 0.1169 mg/L,0.2110 mg/L,10.53 mg/L,0.2132mg/L,4.96 mg/L and 46.35mg/L,respectively,of which the LC50 value of the first three pesticides on B.tabaci were all less than 100 mg/L,and the LC50 of the latter three pesticides on B.tabaci were all greater than 100 mg/L,virulence order was 19%Cyanamide bromide suspension agent>10%Cyanamide bromide suspension agent>50%nitenpyram soluble granules>50%Water dispersing granule of fluridinitrilea>80%ene pyridine Pyridoxine water-dispersible granules>40%chlorfenidil and thiamethoxam water-dispersible granules.Field efficacy test results showed that the control effects of 19%Cyanamide bromide suspension agent,10%Cyanamide bromide suspension agent,50%nitenpyram soluble granules,80%ene pyridine pyridone water dispersible granules,50%Water dispersing granule of fluridinitrilea,40%chlorfenidil and thiamethoxam water-dispersible granules on the adults of Bemisia tabaci were 84.51%,78.45%%,83.46%,69.73%,71.54%,and 61.27%,respectively;The control effects on the nymphs of Bemisia tabaci were 95.42%,88.51%,90.48%,62.35%,79.48%,and 55.02%,respectively. |
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