The effects of different colors and different hanging modes for trapping Asian citrus psyllid

Abstract：【Objective】In the field of agriculture, the monitoring and control of color trapping techniques has been widely used in containing field crops, vegetables, fruit trees and flowers and other pests. In order to screen out the best color for attracting Asian citrus psyllid (Diaphorina citri Kuwayama) , evaluations were done of 10 different color sticky cards and determining the best mode for hanging based on different directions, heights and spacing. And based on these results, provide a theoretical basis for the green prevention and scientific control of Asian citrus psyllid, which is a solution to pesticide abusing, pesticide residue, insecticide resistance and environmental pollution.【Methods】Use completely randomized block designs for each treatment. All the experiments were carried out in an orchard garden without management oversight and the orange trees which were growing well and with similar growth stages were chosen for testing. Screen out the best color and directions for attracting Asian citrus psyllid through hanging white, red, cyan, green, grey, black, yellow, purple, blue and pink sticky cards in east, south, west, and north directions to observe and record the number of Asian citrus psyllid detected on sticky cards on the 1, 3, 5, 7, 9, 12 days after hanging. Then use the one-way analysis of variance (ANOVA) to determine which attracted the most citrus psyllids based on the colors and directions. This was then followed by the post-hoc Duncan's test for individual group comparisons and obtaining the best colors and directions for the next experiments. Screen out the best heights for hanging through setting 50 cm, 100 cm, 150 cm, and 200 cm heights in the best colors and directions. Screen outthe best spacing for hanging by setting 2 m, 3 m, 4 m, and 5 m different spacings between the sticky cards in the best colors, directions and heights from the former test. The observations, recordings and analysis modes of the various heights and spacing experiments are the same as the experiments of different colors and directions.【Results】By comparing the effects of attracting Asian citrus psyllid for the 10 different colors, we determined the best color was the yellow sticky card and the average attracting amount after 12 days reached 21.83 per sticky card, which showed a highly significant difference when compared with other colors (p < 0.01) . This was followed by the blue color card, with the average number of insect trappings in 12 days being 12.92 per card, however there were no significant differences when compared to the other 8 colors. In all the 10 colors tested, the colors with the worst trapping effects were pink, black, purple, grey and white. The average number of traps in the 12 days of the east, south, west and north were 13.50, 28.00, 15.50 and 20.50 individuals per card, respectively. The trapping effect in the south was best, which increased significantly compared with the east and west (p<0.05) and had no significant increases when compared with the north. We therefore used the yellow sticky card and the south direction for further height and spacing experiments. The height experiment result showed that when the hanging height was 150 cm, the number of Asian citrus psyllid were the most, which had an attracted mean of 36.75 individuals per card after 12 days and possessed significant differences when compared with heights of 100 cm and 50 cm (p < 0.05) . This was followed by the height of 200 cm, which had an average of 24 individuals per card. So the height of 150 cm was the best in all treatments. The results of the different spacing showed that 2 m, 3 m, 4 m, 5 m were 18.00, 19.67, 32.33, 24.67 individuals per card after 12 days. And when the spacing between cards was 4 m, it possessed a significant difference when compared with 2 m (p < 0.05) and did not with 5 m and 3 m.Though the treatment with 4 m did not have the significant effect as shown with 5 m and 3 m, it was still more than the other treatments. So in practical production, it is better to set the spacing at 4-5 m to guarantee the best effect.【Conclusion】After the experiments with using different treatments and analyzing the data, we concluded that the best way to trap Asian citrus psyllid was hanging the yellow sticky cards in the south of the orange trees, at the height of about 150 cm and setting the spacing of the sticky cards at 4-5 m. Using color trapping as an energy saving, environmental protection and pollutionfree physical means to control Asian citrus psyllid, has the important significance of reducing pesticide usage. At the same time, because of its simple operation, and low cost, it is easy to promote large-scale production practices in practical production. But in the process of spreading the pest attractant sticky cards, the interaction effects of target insects with color, height, azimuth and spacing should be taken into account in order to achieve the best control effect and at the most optimal cost.