1、植物检疫的作用在于                                                    
                                                                         。
2、作物抗虫性是指                                                        
                                                                         。
3、防治地下害虫常用的施药方法是                                          
                                                                         。
4、经济损害水平是指                                                      
                                                                         。
5、经济阈值是指                                                          
                                                                         。
6、作物遗传抗虫性按其机制可分为三类                                      
                                                                         。
7、利用发育进度预测害虫发生期时，当某虫态数量出现百分率达到              
   时称为该虫态始盛期，达到                时为高峰期，达到              
   为盛末期。
8、滥用农药造成的“农药综合症”是指                                      
                                                                         。
9、我国为害最严重的储粮害虫有                                            
                            ，它们都属                               仓虫。
10、抗虫品种对害虫的影响可表现在如下几个方面                             
                                                                         
                                                                         。
11、仓库害虫种群系统的特点有                                             
                                                                         。
12、在植物检疫中，保护区是指                                             ，
    疫区是指                                                             。
13、地下害虫是指                                                         
                                                                         。
14、植物检疫对象是指                                                     
                                                                         。
15、地下害虫综合防治的原则是                                             
                                                                         。
16、“IPM”的科学性与合理性在于                                          
                                                                         。
17、与化学防治比较，生物防治具有以下优点                                 
                                                                         。
18、在制定害虫的防治指标时，一般要考虑的几个方面是                       
                                                                         。
19、在植物检疫中，划分疫区和保护区的重要作用是                           
                                                                         。
20、在作物抗虫机制中，耐害性具有以下特点                                 
                                                                         。