Studies On The Aphid Species On Tobacco, Population Dynamics Of Green Peach Aphid And Its Control In Longyan Tobacco Area

The types of aphid species on tobacco, population dynamics of green peach aphid [Myzus percicae (Sulzer)] and its control were carried out in between 2014 and 2016 at Longyan, Fujian province, China. The main results of the study were as follows:The two kinds of aphids were found, M. percicae and Aphis gossypii Glover, on tobacco during the course of these trials. And the numbers of M. percicae were more than A. gossypii in tobacco.The dynamics of total green peach aphids were similar as the no winged aphids. There were two peak periods for the two aphids in Longmen base of Longyan city corporation of Fujian province tobacco corporation,37 days (first) or 67 days (second) of transplant. In the initial stage of growth (7 days of transplant), the numbers of green peach aphid were less in tobacco. And all of them were winged aphids. In the medium-term stage of tobacco growth (27-57 days of transplant), the numbers of no winged aphids or total aphids were stable. And the numbers of them were more. But in the late stage of growth (77 days of transplant), the numbers of no winged aphids or total aphids were declining. In 7-17 days of transplant, the numbers of winged aphids were less. At the 67th day of transplant, it was the most number for winged aphids.Additionally, the peak periods of green peach aphids were apparent in Yongding or Shanghang county of Longyan city. They were at the 20th day of transplant, but at the 15th day in Changting county. The numbers of aphids were increased for Changting county during the time of growth, while the numbers of other counties were no same as it. In 7-20 days of transplant, the numbers of them were increased, thus decreased in 60 days of transplant. At the 70th day of transplant, then numbers of Shanghang county and Changting county were increased.In 7-30 days of transplant, the rates of tobacco plants with aphids were increased. In 47-67 days of transplant, they were stable, and then the numbers of them were decreased.It was not significant (P> 0.05) between the numbers of aphids in fields and the microclimate (temperature and humidity).It was obvious effect for yellow trap board to control winged aphids in our trials.35 individuals of aphids were trapped by a yellow trap board every day of peak periods. Averagely,15.59 individuals were trapped during the course of the trials. Artificial release of Aphidius gifuensis (Ashmead) had obvious controlling effect on green peach aphid population. The control effect of artificial release of A. gifuensis was 72.77% at the 5th day, and 84.79% at the 25th day. Averagely, the control effect of it was 79.40%. And chemical pesticide also had obvious controlling effect on the aphids. The control effects were significant for different treatments (P<0.05). The control effect of 5% acetamiprid E C was better (92.72%) than the other chemical pesticides in the trials. The control effect of 25% thiamethoxam W G was less (84.68%). And the control effect of 5% imidacloprid E C was middle (88.30%) in the trial pesticides.