| Corythucha ciliate is an insect species, which widely distributes all over the world, such as North America, Europe, South America, Asia and Australia, and it mainly damage the sycamores tree species. By clustering on the back of sycamore leaves and sucking the sap, the nymphs and adults of Corythucha ciliate make leaves turn yellow, fall off earlier, and further affect the normal growth of sycamore trees. Corythucha ciliate was found in Yanzhou of Shandong province in 2009 for the first time, and now it has become the main pest to the sycamore trees in our district. In this article, the biological characteristics of Corythucha ciliate including the living habits and the life circle, and five chemical control methods were studied to find out the most effective prevention measures. It could be provide the technical support for the further popularization and application. The main results in our studies are as followed:Firstly, the living habits and life cycle of Corythucha ciliate in YanZhou were illuminated by systematic observation in our experiments. It showed that the adult insect has stronger reproductive capacity of laying about three hundred eggs at a time. The adults were extremely cold tolerant, they could damage the sycamores until the leaves falling off. Corythucha ciliate overwintered as adults, either in the loose bark, cracks of trunks and major branch, or in nearby dry branches and fallen leaves underground. It could spread rapidly, with the wind and other external forces. Corythucha ciliate in Yanzhou overwintered as adults from late October every year, and the adults laid eggs in early April of the next year. The nymphs were initially found in early May and multiplied to early November. There were five generations of Corythucha ciliate in a year. The first generation maintained about seventy days, and from two to five generation approximately kept forty days. It appeared overlaps from the second generation, and most seriously in July and August.Secondly, according to different forest types, different control methods were adopted, and we have found the effective preventions and control measures. The results showed that in the stage of nymph hatching, pesticide foliar spray, fumigation by smoke machine, trunk injection, trunk base-irrigation can be used for prevention and control. Among them, Emamectin Benzoate foliar spray had the best effect to sycamore green roadways and farmland forests. The efficiency of Emamectin Benzoate 1% EC 2000 times liquid could be as high as 99.3%. For sycamore forests, the efficiency of Nitenpyram 20% and Pymetrozine 60% WDG 2000 times liquid was 98.7%. For those seedling sycamores with high canopy density, the control effect was 97.3% by smoke machine prevention under the tree, using Beta cypermethrin 4.5% EC and Dichlorvos 22.5% OL and diesel oil mixed with volume ratio of 1:1:10. For the street trees in urban areas and courtyard trees, the control effect was 97.8%, using trunk injection of 5% imidacloprid EC. For the seedling of sycamores, the control effect was 92.1%, by trunk base-irrigation of 5% imidacloprid EC 1000 times liquid in the soil. In addition, cleaning the loose bark, dry branches and fallen leaves underground timely in autumn and winter could destroy the overwintering sites of Corythucha ciliate, reduce the overwintering insect source, effectually decrease its happening in the coming year. |
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