| Wheat midge Sitodiplosis mosellana (Gehin) that were classified Diptera Cecidomyiidae is one of destructive pest on wheat. The larvae feed on the juice during the grain filling stage, which cause empty shell, unfilled grains, and caused wheat production drawdown or not yield. This study is divided into two parts:1 The amount and sex-ratios of trapped wheat orange midge adults by black-light lamp.Traditional monitoring methods of wheat midge indigenous have their limitations of wasting of time and wasting energy. Using forecasting network to monitor adult of wheat midge, in improving the monitoring efficiency, has an important significance. Results are as follows:There was significant Correlation between light trap number and visual measurement number at the 0.05 levels, net trap number, and yellow trap number were highly significant Correlation between light trap numbers at the 0.01 level. It was proved that light trap monitoring data and field Occurrence of wheat midge in the field are basically consistent, can be used to monitor the wheat midge occurrence of dynamic ways in the field. The result showed that the midge adults were strongly attracted by the black-light lamp at nights from April 30 to May 19. Numbers of 9 to 5661 wheat midge adults were attracted per night during the investigation period. Among which,7th, May is the peak day when the largest total number of 5661 adults was attracted from 20:00 to 23:30. Male were more than female in the early, female were far more than in the medium, Sex ratio tend to 1:1 in the late. Results indicated that the black-light lamp could be applied as a monitoring tool for the activity of midge adults.2 Cold hardiness of Sitodiplosis mosellana (Gehin) for the population dispersionTo investigate cold adaptation and potential distribution area of Sitodiplosis mosellana (Gehin), we sampled populations from Nanyang and Huixian of Henan province, Xi'an of Shanxi province, Baoding of Hebei province and Tianjin, stepping up 5 different geographical localities.Super cooling point and freezing point of the larvae that the cocoon are broken with 12 hours (the larvae),the cocoon non-broken (the round cocoon) and that the long cocoon of Xi'an population are tested. The range of super cooling points of Wheat midge cocoon round was-8.50℃～28.50℃, the larvae was-13.70℃--28.50℃. The super cooling points both of cocoon round and larvae in Huixian population were highest, Tianjin population were lowest. The super cooling points both of cocoon round and larvae in different geographic populations were significant differences. The results showed that the super cooling point of larval lower than that of round cocoon. The super cooling point order of the round cocoon was Henan Population> Baoding population> Xi'an population> Tianjin population. The super cooling point of round cocoon and larvae generally increased with latitude. There were large variation of Xi'an population and Henan nanyang population, In the three instars, that the gap of super cooling point and freezing point, the long cocoon were largest, the larvae were second, and the round cocoon were minimum. It shows that the long cocoon cold tolerance was increased. The super cooling point of round cocoon and larvae was positively related to extreme low average temperature of January and February, as low long-term adaptation.This innovation is first used the method of oil with yellow plates to stick adult wheat midge, easy to count and sampling, after the method is extended can be used to collect phototaxis in smaller size insects at night. |
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