Ecology Of Eretmocerus Hayati And The Control Effecicacy On Bemisia Tabaci

Bemisia tabaci(Gennadius)(Hemiptera:Aleyrodidae)is one of the major pests of numerous field crops,vegetables and ornamental crops in China and elsewhere worldwide. This insect has caused enormous economic losses in China's agricultural production since the late 1990s'invasion into China. In Beijing, much damage has been brought in the yield of cucumber, tomato, eggplant, summer squash, and melon plants, and sometimes even over 70% of the yield was lost.The biological characters of Eretmocerus hayati were studied here. There is a promising prospect of the insect on biological control of whitefly. On the basis of the establishment of the laboratory populations of E. Sophia, the biological characteristics of the wasp hosted by the nymph of tobacco whitefly was investigated in detail, and the results were as follows:Eretmocerus hayati the developmental time for one generation on tomato, cucumber and cabbage is about 15-16d.And the developmental time on such hosts are significantly different,cucumber>tomato>cabbage. The parasitic capacities are on cucumber,tomato and cabbage are significantly different,8.2d,8.9d and 9.7d,respectively. The survivalship on cabbage is 78.7%,significantly higher than tomato (74.4%) and cucumber (72.5%),but survivalships of the later two are no significantly different from each other.2.The longevities of the three hosts indate no difference, but the longevity is longer on cabbage than tomato and cucumber.The fecundity on cabbage is 74.7,significantly higher than the other hosts;and the cucumber (62.3) is significantly lower than the others.3.AT 20～30℃, the total developmental periods of hayati from egg to adult emerging were decrersed with the incersing of the temperature.at34℃,the developmental time of hayati change longer.adult longevity was longer At lower temperature.The temperature of development zero of immature stage,survival of adult and whole generation strain were 12.3℃,9.2℃,11.1℃,and the effectively accumulated temperatures were 240.7,145.7,372.7day-degrees.