| Oriental armyworm(OAW) Mythimna separata(Walker), an important migratory insect pest, is difficult to forecast. Latest severe OAW outbreak was in north and northeast China in August, 2012. The monitoring on adult OAW still relied on the black light and sweet and sour liquid without using sex pheromone(Rules for investigation and forecast of the armyworm[Pseudaletia(Mythimna) separata Walker], GB/T 15798-2009), while the sex attractant have been used on adult monitoring of cotton bollworm(Rules for investigation and forecast of the cotton bollworm [Helicoverpa armigera], GB/T 15800-2009). OAW should suck nectar to complete migration and reproduction in the field. Can certain volatile compounds from nectar plant flowers be synergistic agents of sex pheromone from female OAW moth to guide the armyworm female and male mating? Do the wider communication channel of OAW moth sex pheromone mean the less importance of sex pheromone than other insect pests such as H. armigera? A preliminary study on synergism of 9 botanical volatile components and OAW sex pheromone by indoor “Y” tube olfactometer behavior test and water pan trap trapping experiments in the field. OAW moth sex pheromone components were quantitatively analyzed by GC-MS. The volatility of 9 botanical volatile components was tested in the laboratory. The results are as follows:1 The volatility of 9 botanical volatile components: the volatiliztion of butyl alcohol、ocimene、benzaldehyde、and β-pinene 4 compounds was rapid, the butyl alcohol in 5μL capillary volatilized entirely within 6h; Phenyl-acetaldehyde、phenyl methano、2-Phenylethanol、ethyl benzoate、and benzyl acetate, volatilized relatively slowly,the ethyl benzoate for 276 hours from 1.58μL, under the same synergistic effect, 5 kinds of slow volatile compounds should be more suitable for OAW lures synergist.2 Indoor Y tube test showed that: botanical volatile component ethyl benzoate was an active synergistic agent of sex pheromone;Ocimene and β-pinene had certain repellent action on armyworm,and ocimene had repellent effect significantly. The synergism of ethyl benzoate(1-20μL) with OAW sex pheromone(1μL)was distinct, while the synergistic effect was weakening with the increase of dose. Phenyl acetaldehyde and ethyl benzoate, phenyl acetaldehyde and benzyl acetate mixed(1:1), the synergistic effect of sex pheromone were also significant. Benzene acetaldehyde, ethyl benzoate and benzyl acetate(1:1:1), was also highly significant synergistic agent of OAW sex pheromone. Synergistic effect was weakened with the increase of Benzyl acetate at following config: mixtue of Phenyl acetaldehyde, ethyl benzoate and benzyl acetate at different ratios; phenyl acetaldehyde and benzyl acetate at different ratios, Phenyl acetaldehyde and ethyl benzoate at different ratio.3 Field trapping test:(1) 9 botanical volatile compounds alone could not catch OAW moth;(2) In benzene acetaldehyde, ethyl benzoate, benzyl acetate of 3 kinds of single agent and compound synergistic trapping experiment.ethyl benzoate(4μL)and the sex pheromone(10μL) caught significant more male OAW moth than sex pheromone alone.(3) Mixture of Phenyl-acetaldehyde and Ethyl benzoate(3:7) was found another active synergistic agent of OAW sex pheromone.4 The extract from 4-day-old adult female sex pheromone gland was sent for GC-MS analysis. The result showed that the sex pheromone components Z11-16:Ald and Z9-16:Ald ratio was 9:91, different from the result reported before.5 The two configuration of sex pheromone(Z11-16:Ald : Z9-16:Ald = 95:5, Z11-16:Ald : Z9-16:Ald =9:91) was carried out to lure male OAW moth by indoor type "Y" tube test. It was found that 4 day old male moths could not prefer to different mixture ratio of sex pheromone. Benzene acetaldehyde and ethyl benzoate mixed by 1:9(1μL) of the new ratio of(Z11-16:Ald : Z9-16:Ald =9:91) sex pheromone lures(1 μL)had significant synergistic effect. |
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