致死因子 meaning in Chinese

lethal factor
lethal gene
lf

Through cultivating the cochineal in 4 counties which belonging to tropical , south sub - tropical and mid sub - tropical zones , the life tables of the cochineal in each county are established and the survival percentage of each stage as well as the key factor of death in each climate type is studied . in the meantime , the sample of the cochineal of each county is collected to test the size , eggs and weight , through comparing these biological index , the best zones , better zones and other zones for cultivation of the cochineal are pointed out . on the basis of above study , the zones for cultivating the cochineal are marked out in yunnan province
在云南热带、南亚热带、中亚热带三个气候类型下的4个县(市)放养胭脂虫，应用生命表技术，研究各气候类型下胭脂虫的存活情况并分析出各气候类型下胭脂虫的主要致死因子，同时，采集各地培育的胭脂虫样品测定虫体大小、怀卵量及重量，通过比较这些生物学指标，得出胭脂虫的最适生区、次适生区及适生区，并以此为依据，对云南省胭脂虫的培育进行了区划。