4类昆虫信息化学物质在不同缓释载体上的释放速率

摘要

【目的】研究目前常用的4种缓释载体对信息化学物质的释放速率，为研发对昆虫信息素和寄主挥发物释放速率稳定、持效期长的仿生诱芯提供依据。【方法】在室内条件下(温度24～26℃，相对湿度50%～80%，气体流速300 mL·min －1)，采用动态顶空吸附法(吸附剂 Porapak Q)在不同时间收集小蠹虫4种聚集信息素成分、松毛虫2种性信息素成分和寄主挥发物2种萜烯成分在4种缓释载体上的释放量，用正己烷洗脱采样管后进行气相色谱定量分析。【结果】在分析测试时间内，聚氯乙烯塑料膜缓释载体( Bubble cap)对小蠹烯醇( ipsenol)的释放速率高于小蠹二烯醇(ipsdienol)，其4种异构体成分在第2，22，29天释放速率差异显著。第2天初次测试时聚集信息素成分具有较高的释放量，然后释放速率持续下降到第15天，第15～36天释放速率又迅速上升并在第36天达到最大释放量，然后又逐渐下降到低释放速率状态。封口的聚乙烯管缓释载体(PE tube，#730)不释放松毛虫性信息素成分顺5，反7－十二碳二烯醛和顺5，反7－十二碳二烯醇，而未封口的聚乙烯管缓释载体释放这2种成分，说明这2种松毛虫性信息素成分不能穿透聚乙烯管缓释载体1mm 厚的管壁而释放。寄主挥发性成分α－蒎烯[S －(－)－α－蒎烯和 R－(+)－α－蒎烯)在聚乙烯塑料瓶缓释载体( PE bottle)中的释放速率前期不稳定，43天后处于平稳低释放状态，释放高峰期内2种成分的释放速率在第15天和29天差异显著；但 S－(－)－α－蒎烯与 R －(+)－α－蒎烯平均释放速率差异不显著。反式马鞭草烯醇和顺式马鞭草烯醇在聚乙烯塑料纸缓释载体( PE pouch)中的释放模式相似，第2～15天是平稳低释放状态；第16天释放速率迅速上升，第36天(反式马鞭草烯醇)或第43天(顺式马鞭草烯醇)达到最大释放量，然后释放速率逐渐下降到低释放状态。在释放高峰期，2种成分的释放速率只有第43天差异不显著，其余时间段均差异显著。【结论】明确了昆虫信息化学物质在4种常用缓释载体上的释放模式及其诱芯在林间的释放动态特征，对评价仿生诱芯在害虫种群监测和防控中的使用效果具有指导意义，可为生产上针对不同信息化学物质选用最适宜的缓释载体提供技术支持。%[Objective]In order to develop effective lures that can uniformly and persistently release biologically active semiochemicals in the field,it is necessary to determine the release rates of various insect pheromones and host volatiles from different types of commonly used dispensers after the active compounds are identified. [Method]In this study,the release rates of four common bark beetle aggregation pheromone components ( ipsenol,ipsdienol,trans-verbenol and S-cis-verbenol),two major Dendrolimus sex pheromone components (Z5,E7-12:Ald and Z5,E7-12:OH),and two conifer host volatiles ( S-( - )-α-pinene and R-( + )-α-pinene ) from four different types of dispensers were investigated under laboratory conditions ( temperature,24 -26 ℃; relative humidity,50%-80%; wind speed,300 mL·min -1 ) using dynamic headspace volatile collection method. The entrapped components on Porapak Q were extracted from sampling tubes with hexane and quantified by Gas Chromatography. [Results]Results indicated that ipsenol had higher release rates than ipsdienol from the polyvinylchloride bubble cap dispensers over the test period,showing significant differences for both ( +) and ( -) enantiomers of ipsenol and ipsdienol on day 2 ,22 ,and 29 . Ipsenol and ipsdienol released quickly in the first two days and gradually declined to the lower release level on day 15 ,then increased sharply during days 15 -36 with a peak of release rates at the day 36,but finally declined to a consistent low release level. The closed polyethylene (PE) tube dispensers (#730) did not release any Dendrolimus sex pheromone components (Z5,E7-12:Ald and Z5,E7-12:OH) while the open PE tubes released them,indicating that these two moth pheromone components can’t penetrate the 1 mm thick PE wall. The release rates of these two conifer host volatiles,S-( -)-α-pinene and R-( +)-α-pinene from the PE bottles varied over the whole testing period;with ups and downs during the earlier test period,reached the peak between 2 to 4 weeks after the start,and maintained at low level after the 43 th day. The release rates between these two components on day 15 and 29 were significantly different,even though the differences in their overall average release rates were not significant. Release rates of trans-verbenol and S-cis-verbenol from PE pouch maintained a relatively low level during the first two weeks,then increased sharply to a peak on the day 36 for trans-verbenol or the day 43 for S-cis-verbenol,and then dropped to and maintained at a low level after their corresponding peaks. trans-verbenol showed significantly higher release rates than did S-cis-verbenol throughout the testing period except at the day 43 .[Conclusion]Studies of these release patterns of different semiochemicals from different types of dispensers could help us understand the dynamic releasing characteristics of various volatiles in the field,and their potential effects on the semiochemical-based monitoring and control efficacies. Finally,these results would provide some critical information on the selection of optimal dispensers for different semiochemicals in the pest control program.