The Effect Of Temperature And Soil On Development Of Western Flower Thrips Frankliniella Occidentalis (Pergande) And The Predation Of Orius Sauter (Poppius)

The western flower thrips (WFT), Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae), is one of the most important and widespread pests of glasshouse crops and causes damage to over 200 species of vegetables and ornamentals through direct feeding damage and disease vectoring. When growers use chemicals as the main cantrol measure high insecticide efficacy is critical because F.occidentalis usually developes resistance quickly to insecticides. This pest was firstly recorded in China mainland in Jun 2003 and no detailed studies on this pest has been conducted in China mainland until today. The paper deals with the biological characteristics of F. occidentalis and predation of Orius sauteri (Poppius) to F.occidentalis. The results were beneficial to knowing about F. occidentalis and maybe help to the biocontrol.(1) Effect of temperatures on development and survival rates of F. occidentalis.The total developmental periods from egg to adult of the thrip at the temperature of 15 ℃-30℃decreased when the temperature increased ranging from 28.27 days at 15 ℃ to 9.25 days at 30 ℃. Based on the direct optimum method, the threshold development temperature was 6.23 ℃ and the effective accumulative temperatures was 219.73 day-degree.The survival rates of the thrip increased with temperature increasing at the range of 15℃-25℃,but the survival rate is the lowest when the temperature arrived at 30℃. The optimum temperature for thrips population growth was 25 ℃.(2) Effect of soil on pupation of thripsThe result showed that soil has no obvious effect on pupation of thrips. The eclosion rate is 27.49% when the cucumber was planted in soil and 15.52% when the cucumber without soil.(3) The behavior of oriusThe behavior of orius was categorized according to seven events: walking,feeding, probing, grooming (predators making rapid movements with its fore and hind legs across its body surface and antenn), resting, orienting (predator probing on the leaf without advancing in any particular direction). Observations revealed that the...