论文部分内容阅读
经在1984年的初步调查试验,用Morris-Watt根据生命表数据所建立的数学模式进行统计分析,以种群数量发展趋势指标Ⅰ值来看,得知大突肩瓢虫在桂南蔗区田间的种群数量变动情况为4-5月间和10月发生的世代的Ⅰ值远大于“1”,而7、8、9月份发生的世代的Ⅰ值则小于“1”,说明5-6月份和10-11月份此虫在田间的存活率较高,种群数量较大.从各世代各虫期的存活率来看,此虫卵期的主要致死因子是“不孵”和“捕食”;幼虫期和蛹期的主要致死因子是“捕食”及“失踪”,4～5月这两个虫期的主要致死因子除“捕食”和“失踪”外,还有“寄生”因子.大突肩瓢虫(Synonycha grandis[Thunberg]是甘蔗绵蚜的主要天敌之一,1982年以来,我们开展保护利用本种瓢虫防治甘蔗绵蚜试验,已取得了成效.为了进一步提高保护利用大突肩瓢虫防治蔗绵蚜的技术水平,1984年在蔗田对引起该种瓢虫种群数量变动的主要因素进行了初步考查,并以全年不同季节的考查结果,应用Morris-Watt提出有关的数学模式计算分析这些因素与该瓢虫种群数量变动的关系.
After a preliminary investigation in 1984, using the mathematical model established by Morris-Watt based on the life table data, statistical analysis was conducted. Based on the index Ⅰ of the population trend index, it was found that the ladybug The change of population quantity in April-May and October was much larger than that of “1”, while the value of “Ⅰ” in the generation of July, August and September was less than “1” The survival rate of this pest in the field was higher and the population was larger in October and November. From the survival rate of each stage in each stage, the main lethal factor in this stage was “not hatch” and “predation” The main lethal factors in larval stage and pupal stage are “predation” and “disappearance”. In addition to “predation” and “disappearance”, the major lethal factors in the two stages of April-May are “parasitic” Synonycha grandis [Thunberg] is one of the main natural enemies of sugarcane aphid, and we have achieved some success since 1982. In order to further improve the protection and utilization of the large shoulder Ladybugs prevent sugarcane aphid’s technical level, in 1984 caused the kind of ladybug species in the cane field Based on the test results in different seasons throughout the year, Morris-Watt proposed the mathematical model to analyze the relationship between these factors and the population change of the ladybug.