Abstract:
Abstract: Double cropping rice in southern China is planted starting from May to the end of October. The pests occur in turn during this period, and the rice planthopper, Cnaphalocrocis medinalis, rice stem borer, and Tryporyza incertulas are the most harmful. In order to obtain high yields, farmers must uninterruptedly use various types of agrochemicals for the prevention and control on the outbreak of pests. In recent years, researchers have studied the phototaxis behaviors of rice pests at night. For example, rice leaf folder, Scirpophaga incertulas, Chilo suppressalis, Sesamia inferens, and Oxya chinensis are more sensitive in the violet light (350-400 nm), and rice gall midge, brown planthopper, and white-backed planthopper are more sensitive in the blue light (470 nm) and green (515-550 nm), while aphids (green), thrips, and tabaci are more sensitive in the yellow light (550-590 nm). The use of black light lamp, double-wave lamp, vibration frequency spectrum lamp, light emitting diode (LED) lamp, and so on can prevent and control rice pest, which have achieved good results. Lighting prevention does not produced any pesticide pollution, pest resistance and high cost compared with the chemical prevention. In this paper, we studied the night life regularity of insects and the rhythm of insects to the searchlight trap. For instance, the activity time of rice planthopper, Cnaphalocrocis medinalis and rice stem borer is from 7:00 in evening to 1:00 in the next morning, rice gall midge, brown planthopper, and white-backed planthopper mainly appear in 8:30-10:30 in evening, and Sesamia inferens usually acts from 10:30 in evening to 1:30 in the next morning. In order to overcome the drawbacks that lights were on all night and beneficial insects were captured by the light, we developed the LED multispectral circulating solar insecticidal lamp that can control time cycle and open different spectral peak lamp to kill the corresponding insect at night, which realized the maximization of luring pests and avoided the trapping of beneficial insects to the greatest extent. All experiments started in May and finished in September, 2015, which were carried out in an experimental field in Jiangxi Agricultural University, Shanggao County, Jiangxi Province (longitude of 115°10' and latitude of 28°25'). We investigated the quantity damage and rate of rice planthopper, Cnaphalocrocis medinalis, rice stem borer, and Tryporyza incertulas in test and control area. Results indicated that the developed lamp had larger trapping force towards rice pests, and trapped a total of 5 orders, 10 families and 19 species, mainly including Lepidoptera, Pyralidae, Cnaphalocrocis medinalis, stem borer, Tryporyza incertulas, and Plecoptera Delphacidae Laodelphax striatellus, brown planthopper, Sogatella furcifera, Diptera, Culicidae giant mosquitoes and rice gall midge. In addition, there were also a few pests of Coleoptera and straight wing. The percentages of the trapped pest were 32.5% for rice leaf folder, 25.6% for Chilo suppressalis, 25.15% for Tryporyza incertulas, 9.35% for rice planthopper, and 6.90% for other pests. The number of moths and eggs of rice leaf folder and rice planthopper per 667 m2 in rice fields of the light area was 62.5% of that in the control area. The amount of eggs in the light area significantly reduced, and it was not necessary to use agrochemicals for the preventation. The use of agrochemicals reduced by 2 times in the light area compared with the control area in July. This light also killed beneficial insects such as ladybird, ground beetle and grass ridge worm, but the ratio of pest to beneficial insects was 1:0.0089, which had less effect on beneficial insects. Therefore, it is very beneficial to the ecological balance. From the viewpoint of economic efficiency, the costs of agrochemicals and labor decrease significantly. Although the cost of the installation and maintenance is increased, the total cost is decreased. The lamp can effectively kill the rice pests, reduce the amount of pesticides used in the rice growing process and improve the economic efficiency.