Volatile Repellents Screening And Application To Control Whitefly Bemisia Tabaci In Sunlight Greenhouse

Bemisia tabaci (Gennadius) is an important insect pest of the world, and is distributed in Asian. Africa, Europe. America, Oceania etc. As its hostplants, more than600plant species belonging to74families were identified. It has different preference to different host plants. Because of it’s rising harm to crops, strategies and methods of effective governance have been searched for in the word. Its prefered host plants are cucumber, tomato, etc. From2013to2015. basing on the former related researches the author used straight tube olfactometer and network rooms studied the potential repellent compounds of B. tabaci in laboratory and greenhouse, and sreened out a better ratio of repellent compound mixture, and carried out a series of indoor measures to chose a better way to use the repellent At last, a synthetical evaluation was done to make clear if the repellent compound mixture with the other techniques such as yellow board, silver reflective tape etc. has a synergistic to control the whitefly. All of the experiments were conducted in Insect Ecological Laboratory of China Agricultural University and Tangshan suburbs. The main results are as follows:(1) Screening out repellents of B. tabaciSeven volatile repellent chemicals and mixtures were tested by BCBT (binary-choice bioassay tube), the results showed all the seven repellents cause dose-dependent avoidance to the whitefly, whereas the control tween20did not. Olive oil added to the mixture in the ratio of D-Limonene-. Citral:Olive oil63:7:30(DLCO) has the best avoidance effective than other mixtures or monomers.(2) The toxicity of DLCO to B. tabaciThe safe concentration of DLCO and the other repellent chemicals to cucumber or tomato was1%. All the repellent chemicals caused no mortality to the eggs, nymphal stages, pupae and adults treated.(3) The repellent test of DLCO and ways of applying of DLCORepellent tests of DLCO were made, and two ways that DLCO being sprayed or controlled releasing were compared. Results showed by both choice and no-choice tests that the controlled releasing has a better repellent range and longer repellent period than the spraying.(4) The repellent test of DLCO to natural enemy and application of DLCO in green houseResult of test shows that DLCO can not repellent Orius similis Zheng, Chrysoperla sinica Tjeder, Coccinella septempunctata Linnaeus.The combination of controlled releasing DLCO, yellow board and silver reflective tape was applicated in green house, showed an effective result in preventing and controlling B. tabaci.(5) Related studiesLaying grass pads on ground in greenhouse:that could reduce weeds effectively, lower humidity and control many plant diseases, and by combining it with DLCO, yallow board and silver reflective tape the pests of whitefly, weeds and diseases will be controlled in a’green way’. Sensilla and olfaction of Q cryptic species of B. tabaci:the sensilla in flagellum are the main odor organ of B. tabaci in both sexes. There should be a relation between the flagellum sensilla and the odor of host plant and repellents.