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Co-effect Of Rice Volatile And Sex Pheromone To The Striped Stem Borer, Chilo Suppressalis Walker

Posted on:2008-07-08Degree:MasterType:Thesis
Country:ChinaCandidate:W ZuoFull Text:PDF
GTID:2143360212995210Subject:Agricultural Entomology and Pest Prevention and Control
Abstract/Summary:PDF Full Text Request
The rice striped stem borer (SSB), Chilo suppressalis Walker (Lepidoptera: Pyralidae), which is one of the most injurious insect pests of rice in China, has become ascend current in population density and caused more damage to rice in recent years. To date, there has been much research reports on the interactions between host-plant volatiles and the sex pheromones of insects in pest control, but little is known about C. suppressalis. This thesis studyed electroantennogram response of C. suppressalis to volatiles from rice and their combinations with sex pheromones, and compared the trapping efficacy of several types of trapping equipments to C. suppressalis, and assessed the effectiveness of the application of sex pheromones in the control of C. suppressalis in the rice field.We measured the responses of electroantennogram (EAG) of C. suppressalis female and male moths to the volatile compounds produced by host plants and their mixtures with synthetic sex pheromones of C. suppressalis female moths. The results showed that (Z)-2-hexenal, (Z)-3-hexenyl acetate, (-)-trans-caryophyllene elicited strongest responses and n-octadecane was lowest from female antennae of C. suppressalis. (-)-trans-caryophyllene, (Z)-3-hexenyl acetate, n-Eicosane, 2-methylacetophenone elicited remarkable responses from male antennae of C. suppressalis, and strongest of which is (-)-trans-caryophyllene which up to -3.0004 mv, lowest is zingiberene. Exposure to volatile compounds stimulated stronger electroantennographic responses of male C. suppressalis than female. When mixed with sex pheromone, some volatiles, e.g. (Z)-3-hexenyl acetate, n-pentadecane, n-hexadecane, linalool elicited stronger responses from male antennae than volatile compounds alone. Volatile compounds, which mixed with sex pheromone, enhanced recovery velocity of EAG significantly.Lepidopteran sex pheromones have been used to monitor and control pest population in field. The trapping efficiency is depends upon the goodness of combination of pheromone chip and trap facility. Through the comparison of effects of the several combinations of C. suppressalis pheromone baits including rubber chip and capillary bait and trapping facility including water tray and cylinder in the field, the results showed that traditional trapping equipment (rubber bait plus water tray trapping) had better trapping efficacies than the new cylinder trapping equipment (capillary bait plus cylinder trapping), which elicited difference significantly. In the catching process of male moths of C. suppressalis of the first and second generation, the trapping facility had significant influence on trapping efficiency, while the type of baits had no significant effect on the efficiency. These data implied that chemotaxis and approaching behavior of male moths to the pheromone baits should be observed in detail in order to redesign the facility and improve the trapping efficiency.Through field experiments of three seasons in two years , effect of mass trapping and/or mating disruption using synthetic sex pheromone has been evaluated which could be used for controlling egg mass and decreasing damage in paddy field.In the single corpping season of the year 2005, mean density of egg mass of the second generation from late-July to early-August, and percentage of damaged rice hills in middle- and late-August, in the sex-pheromone trapping plots was significantly lower than those in the untreated plots. In the first and second rice cropping seasons, the lowest percentages of rice damage were recorded in the capillary sex-pheromone trapping plots. In the first season, percentages of rice hilled protected on May 19, May 24 and June 5 in the pheromone trapping plots was 86.6%, 55.6% and 37.9%, respectively, calculated on the density of damaged hills in the untreated observatory plots, and 66.3%, 32.7% and 33.4%, respectively, on the base of damage in the conventional chemical control plots. The mean density of the second and third generation of the stem borer was significantly lower than those in the untreated control plots and in the conventional chemical control plots too.
Keywords/Search Tags:Chilo suppressalis (Walker), sex pheromone, plant volatiles, electroantennogram (EAG), bait, trapping facility
PDF Full Text Request
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