三化性桑蟥自然种群数量动态分析

Dynamic Analysis on the Population of Natural Racial Group of Trivoltinism Mulberry White Caterpillar, Rondotia menciana Moore

采用生命表的形式研究了三化性桑蟥自然种群数量动态规律。通过计算各世代I值和IPC值 ,并进行组分分析证明 ,在自然环境中桑蟥的种群控制指数较低 ,繁殖率、生命率很强。种群增长虽然各世代有所区别 ,但I值都在 11以上 ;第 2代桑蟥的世代周期短 ,增长指数大 ,环境控制能力弱 ,容易蔓延 ,造成第 3代桑蟥迅速增长 ,形成灾害性危害。

The number dynamic law of natural racial group of the trivoltinism mulberry white caterpillar was studied Using life table.Through calculating the I and IPC values of all the generations and analysis on the factors,the results showed that the racial group control index of mulberry white caterpillar in the natural environment was low,while the reproduction rate and viability were high.The I value was higher than 11 although the racial group increasing was different among the generations.The second generation showed short cycle,high increasing index and easy spreading,which caused the third generation to increase quickly,and finally,a disastrous damage.