Dynamic Study On Forest Pests Trapped In Zhengzhou Areas By The Use Of Light

In this study, 145004 insects in 168 kinds of 42 family of 11 order have been trapped between 2008-2009, in which there are 141008 pests in 161 kinds of 36 family of 7 order, accounting for 99.31%; there are 996 beneficial insects in 7 kinds of 6 family of 6 order, accounting for 0.69%.The ratio of beneficial insects to pests is 1:144.19. Among the trapped pests, 120 kinds of 122964 in Lepidoptera account for 85.39%; 5 kinds of 1012 in Hemiptera account for 0.7%; 2 kinds of 3 in Homoptera account for 0.002%; 7 kinds of 566 in Orthoptera account for 0.39%; 1 kind of 1331 cockroach in account for 0.92%; 1 kind of 398 in Diptera account for 0.28%; The results from trapping by use of light show trapping insects by use of light can collect a large quantity of insects, can be used to monitor forest pests effectively.According to statistics, there are 115 kinds of pests in mingled forest, 92 kinds insingle forest, but the kind of dominant pests in mingled forest is less than that in single forest by 50%. In mingled forest there are 13 kinds of dominant pests such as Chinese pistacia looper, splendid knothom moth, narrow yellow-tipped prominent, peach horn worm, white tussock moth etc. In single forest there are 23 kinds of dominant pests such as oleaster looper, splendid knothom moth, black cutworm, poplar small moth, snowy-yellows spot tiger moth etc.129653 pests had been trapped in two standard single forest, 127839 belong to dominant group. 64827 pests had been trapped in a single forest, 63920 belong to dominant group; 14355 pests had been trapped in a single forest, 7562 belong to dominant group. The study results show that there are less dominant pests in mingled forest, and it is less likely to produce hazard. Therefore, mingled forest should be planted to increase biological diversity, improving the resistance against pests.The general production tendency of trapped pests show that spring and autumn are two key periods for prevention, especially period between June and August, during which approximately 500 pests in 40 kinds can be collected. According to the study results, adult’s change tendency with time has been drawn, and its relativity with meteorological factor has been analyzed, illustrating the production law of main pests in Zhengzhou areas, which provides technical support for precise prediction.Oleaster looper produces one generation each year and takes the shape of pupa in winter, most of them emergence between the last ten-day period of February and early March. Chinese pistacia looper produces one generation each year; most of them emergence during the last ten-day period of June. Poplar small moth produces four or five generations each year and takes the shape of pupa in winter, most of adults emergence during the last ten-day period of April. The first generation adults emergence during the first ten-day period of June; The second generation adults emergence during the first ten-day period of July; The third generation adults emergence from the end of June to early August; The fourth generation adults emergence during the end of August. Metallic-green beetle produces one generation each year, its hazard period emerges from the middle June to middle July. White tussock moth produces three generations each year; adults emergence during the first ten-day period of June.