Studies On The Biology And Control Of Frankliniella Occidentalis (Pergande)

Western flower thrips Frankliniella occidentalis(Pergande),first found in Beijing,2003,is a cosmopolitan greenhouse insect pest and one of the most important quarantine pests in the world. This test studied some biological and bionomical characteristics of this pest, including life stages,developmental threshold and day-degree requirements,longevity,NO. and situation of laid egg,the survival rates of different stages,the procreation table of experimental population,the population dynamics, investigated the occurrence and host addiction character in Beijing, and researched some efficient methods(e.g. coloured card trap, entomopatholgenic fungi) to control F. occidentalis.We drew some conclusions through studying in lab and field. As followed:Under 14℃,18℃,22℃,26℃,30℃,the period of F. occidentalis 'adult was 33.62d,26.54d, 19.10d,12.05d,8.99d respectively; the period of eggs was 12.11d,6.38d,5.86d,3.62d,3.01d respectively, the period of nymph was 2.41d,7.32d,6.89d,4.97d,3.98d respectively, he period of pupa was 9.05d,5.04d,4.72d,2.21d,2.83d respectively. With the increase of temperature, the growth rate was increased. According to the priority law, the threshold temperature and effective temperature sum of egg, larva, pupa and egg-to-adult were 8.1686℃,66.7577 degree.day;8.8213℃,93.1758 degree.day; 10.43 56℃ ,42.9243 degree.day;7.9424℃ ,245.30 degree.day respectively. Under 14-30℃,the average longevity of the adults was 32.58d,28.64d,25.24d,16.08d, 15.54d respectively. The developmental durations and longevity of the adults was shorted gradually with the increase of temperature. At 22℃, F. occidentalis population had the highest intrinsic increase rate r_m(0.3589), the finite increase rate λ,(1.6232d-1), the net reproductive rate R0=28.3620/generation; At 14℃, F. occidentalis population had the lowest r_m(0.1063); At 30℃,the population had the lowest λ,(1.3085 d-l)and R0=10.2350/generation;With the increase of temperature, the mean generation time T was increased clearly. Number of eggs is very little at the lower temperature (14 and 18℃).In sum, the higher temperature (above 30℃) is harm to the population, and 18-22℃ is the range of the fittest.Systemic surveillances were conducted to occurrence and host addiction character of Frankliniella occidentalis(Pergande) in Beijing. It was revealed that the numbers of incidence spots increased from 2 districts in 2003 to 6 districts in 2005; the range of host plants of...