研究了甜菜夜蛾雌蛾求偶行为和腺体中性信息素滴度时日变化的规律.结果表明,雌蛾求偶行为和性信息素滴度均呈明显的昼夜节律,且均在暗期的中后期达到高峰.比较而言,雌蛾的求偶活动期较短,在暗期中期开始,暗期结束后很快停止;但峰期较长,从中后期达到高峰后一直保持到暗期结束.而腺体内4种性信息素组份从暗期前0.5 h到下一个光期4.5 h均有产生;但峰期很短,暗期6.5 h显著增加达到高峰后,在8.5 h又迅速回落.日变化研究表明,甜菜夜蛾当日龄即可求偶,3日龄起进入求偶盛期,至7日龄末有明显减退.0～3日龄雌蛾的平均初始求偶时间逐日显著提前,以后则稳定在暗期5 h左右.不同日龄间性信息素滴度的变化较小.%Beet armyworm (BAW), Spodoptera exigua, is becoming one of more and more serious pests in China in recent years. As a part of research program of sex pheromone and its application of BAW in China,the hourly and daily variation of calling behavior and pheromone production of BAW females were investigated. Both calling behavior and titers of 4 sex pheromone components showed distinct diel rhythms, and the two peak periods were synchronous. In comparison, the calling activity lasted shorter period of time with a longer peak time, whereas the production of the sex pheromone lasted throughout the whole scotophase and part of the photophase with a very short peak time. The calling behavior began at the middle scotophase, reached the maximum at the middle-later scotophase, and continued the maximal calling activity until the end of the scotophase. When the light was on, the calling percentage reduced sharply, and all females stopped calling 1 hour later. The variation patterns of the 4 pheromone components in the glands of the 3 day old moths were similar from one to another. From 0.5 h before to 4.5 h into scotophase, the titers increased slightly, but at 6.5 h they showed a significant increase up to the peak values of the scotophase. Soon at 8.5 h into the scotophase,they decreased significantly and thereafter gradually to undetectable level at 4.5 h into the next photophase.The daily change experiment showed that BAW females began calling at 0 scotophase, became fully active in calling at 3rd scotophase, and maintained the calling activity to 7th scotophase. There was no significant difference in pheromone titers among different day-old moths.
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