| Pest mites are becoming serious in recent years in tea plantations. Studies on the population dynamics of pest mites and beneficial mites are important for scientific pest-mites management and sustainable development of tea industry. The research was carried out during Apr. 2004 to Sep. 2005 at the tea plantation of Fujian Agriculture and Forestry University. We focused on population dynamics and development of pest mites and beneficial mites within five tea varieties. Results were as follows:1. The population dynamics of pest mites were investigated by the quincunx-sampling method from Apr. 2004 to Sep. 2005. The results showed that the peaks of pest mite populations on different teas all occurred between late Aug. and early Sep. As far as Comparing annual results, except Huangdan and Maoxie varities, the maximum of the index of pest-mite situation (IPMS) in 2004 was obviously higher than that in 2005. Comparing among tea varieties, during 2004, at the meridian of pest mites, IPMSs were ranked as follows: Fuyun NO.6 (8.47/time) >Tieguanyin (7.94/time) >Rougui (5.24/time) >Huangdan (3.33/time) > Maoxie (2.89/time) . The dynamics of IPMS was divided into three stages. At the third stage, about at the meridian of 2005, IPMS appeared strikingly different among these tea trees( F=4.141, p=0.0054 ) . They rank as follows: Maoxie>Huangdan>Fuyun NO.6>Rougui>Tieguanyin.2. Using a vibrating method, we collected four phylums including Prostigmata, Mesostigmata, Astigmata and Oribatida, about 64 species. Species belonging to Astigmata and Oribatida had not been further identified. Species in Prostigmata and Mesostigmata were identified into 17 families, with four families of pest mites(about 14 species) and 11 families of predatory mites(about 50 species). This showed that the resources of beneficial mites were rich and worthy preserving.3. The population of beneficial mites had two peaks, once during February to May and another, June to September. However, the maximum population counts differed among different tea variesties. The sequence of population from high to low was as follows: Maoxie (112/time) >Huangdan (72/time ) >Tieguanyin (68/time ) > Fuyun NO.6 (61/time ) >Rougui (50/time (during the first peak) , and Tieguanyin (132/time) > Huangdan (113/time) > Maoxie (112/time) > Rougui (86/time) > Fuyun NO.6 (62/time) (during the second peak).4. The diversity index (DI) about acarids over time was analyzed by the Shannon-Wiener formula. The results showed that DIs on the five tea varieties fluctuated during the period of investigation. All had its own features. We can generally conclude that when the temperature was high and appropriate, DI would be relatively high. Otherwise, when the temperature was relatively low, DI would be also low. Except that DI peaked in April on one tea variety, The DI on others reached the peak all around July or August, which had relatively high temperature. The maximum of DI on the different tea varieties was ranked as below: Huangdan(2.6170/time) >Rougui (2.5374/time) >Tieguanyin (2.4452/time) >Maoxie (2.1380time) >Fuyun NO.6 (2.0814/time) .5. Correlation analysis was conducted between DI and physical and chemical indices of tea varieties. Results showed that the spikey layers of lower and upper epidermis, caffeine and GC etc. were significantly correlated with DI. The thickness of spikey layers of lower and upper epidermis was positively correlated with DI. Caffeine and GC had a slightly negative... |
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