Diagnosis and Treatment of a Case of Femoral Neck Fracture in Cat

Shasha ZHAO Lijun DING Huagen YUAN Wei YAN

Abstract［Objectives］ This study was to find out the effect of trap space layout on the trapped number of Spodoptera litura in tobacco field.

［Methods］ From 2015 to 2017, investigations were made using different hanging heights, distances (densities) and equidistant plane layout in the tobacco planting area in central Guizhou Province.

［Results］ The trapped number of S. litura was different at different hanging heights of the trap, and some had the difference reached the 5% significant level in the trapped number. The optimum hanging height was 1.5-2.0 m. The trapping effect was the best at the field layout distance of 20.0-30.0 m (density of 5-8 traps/hm2). Under the conditions of even distribution at the equal distance between traps of 40.0 m in the field, the accumulated trapped number of S. litura from April to August was in the order of outer ring > central ring > inner ring, presenting the zonal distribution. The difference in the trapped numbers was significant among different rings, reaching the 5% significant level. ［Conclusions］ This study provided theoretical bases for the physiochemical control of S. litura in tobacco field.

Key wordsTrap; Tobacco field; Space layout; Spodoptera litura; Trapped number; Effect

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Received: September 6, 2018Accepted: October 9, 2018

Supported by the Science and Technology Project of Guizhou Tobacco Company, China (201510).

Fei DAI (1968-), male, P. R. China, senior agronomist, devoted to research about tobacco science and technology research, management and production guidance, Email: df6861@163.com.

*Corresponding author.

In recent years, Spodoptera litura has risen to one of the main pests in the tobaccogrowing area［1］, causing great losses to the yield and quality of tobacco［2］. Some tobaccogrowing areas have carried out chemical pesticide screening and application in order to rush to cope with the emergence of pests. Although it has achieved certain effects in the short term, it also leads to excessive pesticide residues in tobacco leaves. Currently, the biological control of S. litura has been carried out in different degrees throughout the tobaccogrowing areas for less pesticide residues to ensure the safety of tobacco leaf raw materials［3-5］, but most is the comparison and screening tests and research on some biological pesticides［6-7］, different traps［8-9］, pheromones［10-11］ and so on. The research on the biological control of S. litura is relatively fragmented［12-16］, and the systematic research is not enough. In order to better control S. litura, in this study, the physical and chemical control of S. litura was carried out in the central tobaccogrowing area of Guizhou Province, and an allround exploration was made to the space layout of traps to control S. litura in the tobacco field to determine the reasonable layout of the traps, thereby maximizing the control effect and saving the control costs, so as to provide theoretical bases for the physical and chemical deception and control of S. litura.

Materials and Methods

Test materials

The test lures were the polyethylene capillary lures (made by Guizhou Institute of Biotechnology), and the test trap was a vertical trap (produced by Ningbo Newcon Biotechnology Co., Ltd.).

Test methods

Tests on the hanging height of the traps

The traps for S. litura were hung at the heights of 1.0, 2.0, 5.0, 15.0, 30.0 and 50.0 m (if the height was too high, the traps were hung on the floor or on the branches), respectively. And 3 traps were randomly hung with a semidiameter of at least 50.0 m each (linear distance over 100.0 m between 2 traps), 3 times repeated, and the total number of trapped S. litura was counted after 15 d of trapping.

Tests on the layout distances (densities) of the traps

A total of 5 tobaccogrowing plots with the planting area over 3.3 hm2 were selected from the same area with flat terrain surrounded by mountains, woods or other crops. The traps were evenly distributed in the plots at the hanging height of 2.0 m with the distribution semidiameter of 10.0 m (linear distance of 20.0 m between 2 traps), semidiameter of 20 m (linear distance of 40.0 m between 2 traps), semidiameter of 30.0 m (linear distance of 60.0 m between 2 traps), semidiameter of 40.0 m (linear distance of 80.0 m between 2 traps) and semidiameter of 50.0 m (linear distance of 100.0 m between 2 traps). The number of trapped S. litura was recorded every 7 d (the distribution layout was shown in Table 1), and the statistical period was 28 d.

Table 1Distribution distances (densities) of the traps for S. litura in tobacco field

Distribution semidiameter∥m10.020.030.040.050.0

Density∥ Number /3.3 hm2106271875

Tests on the equidistant layout of traps at different levels

The test sites were set in Pingba and Ziyun of Anshun City, Guizhou Province with the area of 3.3-6.6 hm2. The traps were evenly distributed into the tobacco field at a distance of 40 m, and the hanging height was 2.0 m. The number of trapped S. litura in the test plots was investigated from April 15th to August 31st, and the trapped number was recorded every 5 d, and the lures were replaced every other month.

Statistical analysis methods

Statistical analysis of the data was performed using data analysis software such as DPS and Excel.

Results and Analysis

Effect of different hanging heights of traps on the trapped number of S. litura

As shown in Table 2, the traps could catch S. litura at the hanging heights from 1 m to 50 m (even higher), and the trapped number was the largest at the hanging height of 2.0 m, when the number was 607.67. There was only a small difference in between the hanging height of 1.0 and 5.0 m, which had the trapped number of 472.67 and 393, respectively, while the total trapped number of S. litura gradually decreased when the hanging height was over 5.0 m. the results indicated that S. litura had strong diffusion ability and large activity space, and the number of active S. litura was the largest at a height of about 2 m. Combined with tobacco growth, climate, cost and other factors, the optimal hanging height of the traps for S. litura was 1.5-2.0 m.

Table 2Effect of different hanging heights of traps on the trapped number of S. litura

Hanging height∥m

Total trapped number

Trap site 1Trap site 2Trap site 35% significantdifferenceMeanVariance

1456535427b472.6755.90

2658589576a607.6744.07

5415388376c393.0019.97

15358313322d331.0023.81

30145137106e129.3320.60

506789117e91.0025.06

Effects of different layout distances (densities) of traps on the trapped number of S. litura

As shown in Table 3, the average trapped number per site showed that the average trapped number per site was the highest in May when the semidiameter of trap setting was 50.0 m (distribution density of 5 traps/3.3 hm2), and the highest number reached 24.8. Moreover, with the decrease of the setting semidiameter (increase of densities), the average trapped number per site decreased, indicating that the average trapped number per site was large when the setting density of traps was small in the field.

Table 3Effects of different layout distances (densities) of traps on the trapped number of S. lituraNumber 

Statistical time∥7 d/time

Average trapped number per site

Distance of 10.0 m(density of 106traps/3.3 hm2）Distance of 20.0 m（density of 27traps/3.3 hm2）Distance of 30.0 m（density of 18traps/3.3 hm2）Distance of 40.0 m（density of 7traps/3.3 hm2）Distance of 50.0 m（density of 5traps/3.3 hm2）

May 70.74.35.710.611.6

May 141.24.86.615.918.2

May 212.16.78.721.924.8

May 281.35.47.313.414.2

Average trapped number in 28 d per site5.621.228.361.768.8

Converted total trapped number597.5573509.1432344

The total trapped number of S. litura in each plot showed that the total number was at the highest point with the trap distribution semidiameter of 10.0 m (density of 106/3.3 hm2) when the cardinal number of S. litura was the largest (from May 14 to May 21). When the cardinal number of S. litura was at the medium level (from May 7 to May 14), the total trapped number of S. litura was less than that with the trap distribution semidiameter of 20.0 m and 30.0 m, which was possibly related with the pheromone release from the traps in the field, which could interfere with each other, resulting in disorientation. The total trapped number was the highest in the plots with the trap distribution semidiameter of 10.0 m, and it was decreased with the increase of distribution semidiameter (decrease of density), indicating that when the cardinal number of S. litura was at a high level, the trapping effect was better at smaller distribution semidiameter (larger density). On the other hand, when the cardinal number of S. litura was at the medium level, the effect was better at the distribution semidiameter from 20.0 m to 30.0 m (density from 27 traps/ 3.3 hm2 to 18 traps/3.3 hm2). In order to better analyze the Relationship between the trapped number and the total trapped number of S. litura by single trap with different distances (densities), a model was set up to analyze the total trapped number and average trapped number per site (Fig. 1). As shown in Fig. 1, the trapping effect was the optimum in the range when the curves of total trapped number and curve of average trapped number per site intersected with the distribution semidiameter from 20.0 m to 30.0 m (density from 27 traps/ 3.3 hm2 to 18 traps/3.3 hm2), indicating that there was a certain correlations between the total trapped number and the average trapped number per site, which could maximize the equilibrium relationship between control effects and economic costs. Combined with Fig. 1 and Table 3, the trapping capacity of each site as well as the controlling capacity of traps was good when the average trapped number per site and total trapped number of S. litura were at the medium levels. Therefore, the control effect was the optimum when the trap distribution semidiameter was from 20.0 m to 30.0 m (density from 27 traps/ 3.3 hm2 to 18 traps/3.3 hm2) in trapping field S. litura.

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Fig. 1Relationship between the trapped number and the total trapped number of S. litura by single trap with different distances (densities)

Effect of equidistant plane layout of traps at different levels on the trapped number of S. litura

The field growth period of fluecured tobacco mainly from May to August, about 120 d, when the focus is on harvesting leaves, and the controlling key is to protect the tobacco leaves from the erosion of pests during this period. According to the monitoring of S. litura throughout the year, there were a total of 5 generations of occurrence peaks, twice in Aprilearly August, so the goal was to control the twice occurrence during this period. Analysis on the trapped number of S. litura at different levels of equidistant plane layout in different landforms in Pingba (Fig. 2) and Ziyun (Fig. 3) showed that the initial population number in Tianlong test area of Pingba was significantly larger than that in Baishiyan test area of Ziyun. The Tianlong test area of Pingba District had flat landform, and the accumulated trapped number of S. litura from April to August in the outer, central and inner rings was 1 609.9, 938.7 and 516.1, respectively. The trapped number in the outer ring of Tianlong test area of Pingba was 71.5% higher than that in the central ring, and the trapped number in the central ring was 81.89% higher than that in the inner ring. The differences were significant at the level of 5%.

Fei DAI et al. Effect of Trap Space Layout on Trapped Number of Spodoptera litura in Tobacco Field



Fig. 2Analysis on the trapped number of S. litura at different levels of equidistant plane layout in the flat tobacco planting area of Pingba from April to August



Fig. 3Analysis on the trapped number of S. litura at different levels of equidistant plane layout in Ziyun mountain tobacco planting area from April to August

Although the difference in Baishiyan test area of Ziyun County was slightly bigger, the accumulated trapped number of S. litura from April to August in the outer, central and inner rings was 1 508, 1 565 and 1 373, respectively. The trapped number in the outer ring was 116.65% higher than that in the central ring, and the trapped number in the central ring was 78.59% higher than that in the inner ring. The differences were also significant. As shown in Fig. 2 & 3, the peak numbers of trapped S. litura in the outer ring of Tianlong of Pingba and Baishiyan of Ziyun in May and August were 447.44, 728.44, 357.25 and 589, respectively. There was significant difference in the number of trapped S. litura among different rings in different months. Moreover, 7 points were selected each from Tianlong of Pingba and Baishiyan of Ziyun at the same locations, and the analysis on the total trapped number of S. litura from April to August showed that in the 2 test areas, the trapped S. litura from the outer ring to the inner ring was in the zonal distribution, and the trapped number in the outer ring was significantly higher than that in the central ring as well as inner ring (Fig. 4 & 5). In addition, the distributions in the outer, central and inner rings were not separated from each other, but relatively continuous, and there were also partial intersections between the rings (Fig. 4). When the trapping point was placed at the place with slightly high elevation or the tuyere position, the trapped number of S. litura was generally larger than that placed in the lowlying land and inner flat, with an average of 43.69% higher. The results from the 2 test areas showed that the total



Fig. 4Distribution of trapped number of S. litura in the flat tobacco planting area of Pingba from April to August

trapped numbers of S. litura in April-August by the traps from the outer, central and inner rings presented an overall zonal distribution (Fig. 6).



Fig. 5Distribution of the trapped number of S. litura from April to August in Ziyun Mountain tobacco planting area



Fig. 6The pattern of field traps in Anshun tobacco planting area from April to August

Conclusions and Discussion

Fist, the trapping effect is the best at the hanging height of traps of 2.0 m for trapping S. litura. Combined with tobacco growth, climate, cost and other factors, the optimal hanging height of the traps for S. litura is 1.5-2.0 m.

Second, the control effect is the optimum when the trap distribution semidiameter is from 20.0 m to 30.0 m (density from 27 traps/ 3.3 hm2 to 18 traps/3.3 hm2) in trapping field S. litura.

Third, under the conditions of even distribution at the equal distance between traps of 40.0 m in the field, the accumulated trapped number of S. litura from April to August is in the order of outer ring > central ring > inner ring, presenting the zonal distribution. The difference in the trapped numbers is significant between different rings, reaching the 5% significant level.

Therefore, in order to achieve the well control of S. litura in large tobaccogrowing area in Guizhou Plateau［18-19］ and avoid blindness and efficiency, apart from factors like sources and climate［20］, it is also one of the essential links to make reasonable spatial distribution of the traps for S. litura, especially the control in the outer ring of tobaccogrowing fields, which is the focus and key of the spatial distribution of the traps for S. litura［21］.

References

［1］ LI YH, CHENG JL, KE MF. Investigation and analysis of the occurrence of Spodoptera litura in the tobacco fields in southern Shaanxi［J］. Shaanxi Journal of Agricultural Sciences, 2014(2): 65-66.

［2］ WU CX, LIAO QR, YANG MF, et al. Financial loss and control index of Prodenia litura on tobacco［J］. Guizhou Agricultural Sciences, 2013, 41(7): 95-97.

［3］ CHEN XH. Green management on Spodoptera litura in vegetables［J］. Shanghai Vegetables, 2018, 02 (15): 50-51.

［4］ LUO HB. Sexual control techniques for Spodoptera litura［J］. Agricultural Technology Service, 2017, 03 (8): 80-81.

［5］ HE YM. Integrated techniques for the green control of Spodoptera litura［J］. Scientific Breeding, 2017 (11): 34-35.

［6］ QIAO BM, LIU XB, TAN SA, et al. Field control effects of several biological insecticides on cigar Spodoptera litura［J］. Science and Technology Vision, 2015(3): 327-328.

［7］ HUANG YZ, ZHANG XZ, ZHOU ZJ, et al. Biocontrol efficiency on Spodoptera litura (Fabricius) in Qiannan tobacco growing areas［J］. Tobacco Science and Technology, 2016, 49(4): 21-25.

［8］ ZHOU HF, YANG XB, XU YL, et al. Control effect of Spodoptera litura by sex pheromone trap［J］. Journal of Anhui Agricultural Sciences, 2012, 40(20): 10432-10434.

［9］ NIU HW, XIAO XY, LIN M, et al. Research on trapping and control effects of different traps with sex pheromone on Spodoptera litura Fabricius of fluecured tobacco［J］. Modern Agricultural Science and Technology, 2016 (4): 108-109.

［10］ ZHENG XW, HU ZL, JIE ZH. Occurrence regularity and screening of sex pheromone of Spodoptera litura in seed lotus fields［J］. Biological Disaster Science, 2018, 06(30): 144-148.

［11］ YANG MW, HE YS, ZHANG KM, et al. Control of tobacco cutworm moth Spodoptera litura (Lepidoptera, Noctuidae) by mass trapping with the synthetic pheromone lures［J］. Journal of Anhui Agricultural Sciences, 2011, 39(28): 17314-17316.

［12］ YU Q, ZHAO JL, ZHOU YH. Effects of trapping tobacco noctuid by settings different heights of two types of moth trapper［J］. Journal of Anhui Agricultural Sciences, 2013, 41(24): 9954-9956.

［13］ LI DC, YANG JL, YANG SG, et al. Effects of different hanging methods of pheromone traps on Spodoptera litura［J］. Plant Doctor, 2014, 27(1): 32-34.

［14］ LI HT, ZHANG QY, LI DP, et al. Control effects of setting different density sex attraction on tobacco pests［J］. Hunan Agricultural Sciences, 2015(3): 34-36.

［15］ LI WY, YANG MW, YA P, et al. Effects of different density of chemical pheromones to control cutworm moth Spodoptera litura［J］. Journal of Anhui Agricultural Sciences, 2012, 40(27): 13363-13366.

［16］ YAO SHI T, ZHENG YL, JIN ZH, et al. Field evaluation of relationship between spacing of sex pheromone trap and control efficiency on Spodoptera litura (Lepidoptera: Noctuidae)［J］. Acta Agriculturae Jiangxi, 2010, 22(6): 116-117.

［17］ ZHENG YL, WANG EG. Comparison of the effects of sexual attraction monitoring and lamp trapping monitoring of Spodoptera litura and the population quality variation model［J］. China Plant Protection, 2015, 35(9): 40-43.

［18］ SHEN JH, SHEN HR, GU DG, et al. Techniques and effects of splicing of Spodoptera exigua and Spodoptera litura［J］. Shanghai Vegetables, 2015(4):72-73.

［19］ HUANG PZ, JI CH, LIN JX, et al. Occurrence characteristics and control measures for cotton leafworm in high altitude of mountainous area［J］. Fujian Agricultural Science and Technology, 2015(5): 55-56.

［20］ XIAO LB, BAI LX, LIU YQ, et al. Effects of different factors on traps with sex pheromone of Spodoptera litura［J］. Journal of Plant Protection,2010,37(4):365-369.

［21］ JIANG SP, PAN Y, SUN YH, et al. Control efficacy of dimensional control techniques on main tobacco pests［J］. Guizhou Agricultural Sciences, 2014, 42(5): 128-131.