Studies On The Occurrence And The Genetic Diversity Of Aleurocanthus Spiniferus In Tea Plant

Aleurocanthus spiniferus (Quaintance) (Homoptera: Aleyrodidae) is an important pest on tea plant. In recent years, Aleurocanthus spiniferus have potential trend to outbreak of disaster in Jiangsu region. In this regard, we carried investigation of population dynamic and pest control in Yangzhou region, which provided science gist and technical sustainment to effective control of this area. At the same time, Aleurocanthus spiniferus as a national pest, penman researched the genetic diversity of Aleurocanthus spiniferus in the country's major tea area. Results are summarized as follows:1.We carried system investigation to Aleurocanthus spiniferus of two different tea spot from May to October in 2009 in Yangzhou. Through system investigation to Yangzhou area, population density and fluctuation law were analyzed in detail. The results showed that: (1) The spatial distribution of Aleurocanthus spiniferus on tea plant is obviously different. The lower distribution is most, followed by middle and the upper is less. The pest number of middle level and lower level account for the total amount about 90%. (2) Aleurocanthus spiniferus occurred in the Yangzhou region 4 generations a year. The number of eggs in mid-May occured on a peak, a second peak in late June, Form late July to mid-August occured a small peak. First instar nymph reached a peak occurred in Middle-late May, Form late June to early-July occured a small amount peak and occurred another peak in middle-August. Second instar nymph only occurred a obviously amount peak in early-June. Third instar nymph and pupa haven't obviously amount peak. (3) The occurrence amount of Aleurocanthus spiniferus on lobule tea is more than big leaf tea. The occurrence amount of Aleurocanthus spiniferus on this two tea plant are differences, but basically are the same.2.Use five kinds of pesticides control Aleurocanthus spiniferus, the results show that: abamectin and chlorpyrifos are best, were 96.50% and 92.30%. Cypermethrin is lower, only 73.08%. Abamectin and buprofezin have a good control on 1 instar nymph, after seven days are 93.63% and 95.62%. for other instar nymph, pseudopupa and eggs are worse. Other 3 pesticides control eggs, nymph and pseudopupa are both worse.3. On the 22 different geographical populations'mtDNA-COI gene sequence of Aleurocanthus spiniferus, analysis showed that: Aleurocanthus spiniferus genetic distance between different populations is small,while genetic similarity is high. The genetic distance of Aleurocanthus spiniferus in Yongchuan of ChongQing province and Guang'an of SiChuan province is much bigger, up to 0.08, others genetic distance are below 0.01. From mtDNA-COI gene sequence phylogenetic tree of the Aleurocanthus spiniferus, genetic relationship between different populations and geographical distribution of certain relevance.4. Used SCAR specific sequence located of Aleurocanthus spiniferus to analyzed 22 different populations. The results show that from the genetic distance table by specific SCAR sequences can be seen Aleurocanthus spiniferus genetic distance among different populations were relatively small and below 0.01. Seen from the evolutionary tree, Aleurocanthus spiniferus in population's different genetic relationship exists between the regional.5. Based on mtDNA-COI and SCAR specific sequence analyzed Genetic diversity of Aleurocanthus spiniferus, the results show that mtDNA-COI and SCAR specific sequence is not suitable for the Aleurocanthus spiniferus research.