Sitodiplosis Pulp Larval Diapause Before And After The Change And Ecological Factors

The orange wheat blossom midge (Sitodiplosis mosellana Gehin) is one of the important pest that intermittently occurs and heavily infests the wheat in Northern Hemisphere. This thesis deals with the effect of light temperature and humidity on the orange wheat blossom midge by experiments and morphological change is observed before and after the diapause in microscope and scanning electronic microscope, these results will offer the basis of predicting and forecasting, regulation of disaster and integrated management in large area.1. Ecological factor research indoorExperiments on light influences the larvae diapause shows, the rate of the round cocoon in 12H-14H is similar to the rate under the natural light.The round cocoon larvae increase apparently when the light length exceed 14H, furthermore,longer the light time, more the diapause larvae, it elucidates that the sensitive light time to larvae diapause is 12H-14H.Experiments on effect of temperature and humidity on the larvae activity in the soil show that low temperature has an effect on inducing pupation of the larvae and eclosion of the adult,20 癈 or low humidity has an advantage of the cocoon formation and surviving in the soil.Temperature and humidity have an important effect on the larvae surviving in the ears of wheat,low temperature or high humidity benefit to the surviving of larvae in the ears of wheat.Temperature and humidity influence pupation of the larvae and eclosion of the adult in the larvae of getting rid of diapause show the suitable temperature or humidity is 20 or relatively high humidity.The number of larvae broken cocoons vary distinctly in different time,this result shows the depth of diapause in the orange wheat blossom midge is different in different time,the depth of diapause on Dec.20 is deeper than on Oct.20 in the round cocoon larvae.2. The observation of the appearanceThe observations of the appearance to the larvae in different time under the microscope and the scanning electronic microscope show that the larvae in the appearance varies to some extent in different time,especially in the locomotion organ on the sternum and humidity sensillum on the segment,the organ of the locomotion on the larvae in the ears of wheat and shallow diapause is sharp and the organ in diapause is blunt; humidity sensillum on the larvae in the ears of wheat and shallow diapause is apparent and the humidity sensillum in diapause is indistinct.