| Pest Risk Analysis (PRA) is a new research field that arose in the 1990s last century. With more and more serious harms caused by biological invasion, it has already aroused the attention from governments of various countries. PRA is the most effective means to reveal the risk of biological invasion and can offer scientific bases for government decision. it can not only protect national eco-system security and health , ensure normal international trade, but also keep the technological barrier function of quarantine, play the protection role of quarantine, promote world trade through plant quarantine, and increase the market access chance of national agricultural products.Western flower thrips, Frankliniella occidentalis (Pergande), is a cosmopolitan glasshouse insect pest in the world and has already caused numerous calamity losses of crops to a lot of countries due to its wide host, fast breed and high resistance to many pesticides. In 1985, it caused up to 20% losses of cucumber of greenhouse of Colombia through directly harming. It was also reported to reduce up to 50%~90% production of clover in Hawaii due to its transmission of the Transmit Tomato Spot Wilt Virus (TSWV). Our preliminary risk analysis shows that the risk of western flower thrips to crops, fruit trees, greenhouse flowers, and vegetables etc. in China is very high, owing to its broad suitable distribution area in China, its high spread ability, its great harms, and the little possibility to control it.CLIMEX is an excellent model to predict the distribution of certain species. But because it only considers climate factors and does not involve the influences of other factors, especially host, prediction by CLIMEX is not so precise as expected. In order to make the prediction more accurate, and to keep the unique advantages of CLIMEX at the same time, we combined the results of CLIMEX with the spatial interpolating function of Geographical Information Systems (GIS), which is able to transform the point data into area data. Besides, such factors as host etc. can be considered through the overlay function of GIS and make the prediction results from CLIMEX model further accurately. Taking advantage of GIS and CLIMEX, the potential distribution area of Western flower thrips was predicted in this paper. It showed that F. occidentalis could prevail in Guangdong, Hainan, Anhui, Fujian, Jiangsu, Shandong, Guangxi, Guizhou, Henan, Hubei, Shanxi, Sichuan, Yunnan, Chongqing etc.. Its north limit of distribution located near 10℃ thermoisopleths of annual average temperature, -8℃ thermoisopleths of averagetemperature in January, and -20 °C thermoisopleths of annual average minimum extreme temperature. F. occidentalis was predicted not able to survive in Xinjiang, Qinghai, Tibet, Heilongjiang, Jilin, Liaoning, Inner Mongol provinces et al.. |
