不同温度对小地老虎实验种群的影响

研究了不同温度对小地老虎发育、存活、生殖、种群参数、种群趋势指数等的影响 .结果表明 :在 17- 35℃恒温内 ,小地老虎的发育速率随温度上升呈逻辑斯蒂曲线趋势 .该虫卵的孵化率 (SE)、幼虫的存活率 (SL)、蛹的存活率 (SP)、成虫产卵量 (E)和种群趋势指数 (I)与温度 (X)变化的回归关系分别为 SE=- 118.94 17+19.0 12 X - 0 .4 2 14X2 ;SL =- 10 7.2 795+18.0 815X - 0 .4 0 4 3X2 ;SP=- 10 6 .0 318+17.7372 X - 0 .384 5X2 ;E =- 4 5.10 2 7+455.50 0 3X - 9.350 4 X2 和 I =- 1757.318+176 .76 59X - 3.6 6 56 X2 .通过不同温度下实验种群参数的比较得出 :2 5℃时内禀增长力最大 (rm=0 .1353) ,2 1℃次之 (rm=0 .130 6 ) ,确定最适温度为 2 1- 2 5℃ .高温不利于种群的生长发育 ,在 35℃时 ,各虫态存活率及成虫产卵量急剧下降 .

Effects of temperature on laboratory population of black cutworm

The experiment was conducted to investigate effects of temperature on development, survival, reproduction, population parameter and population trend indices of black cutworm [ Agrotis ypsilon (Rottemberg)]. Under constant temperature condition in the range of 17-35 ℃, the development rate increased with the temperature as logistic curve. The regression equations of the rate of hatching ( S E), larvae survival ( S L), pupae survival ( S P), egg laying ( E ) and population trend indices ( I ) complying with the temperature ( X ) were determined as: S E =-118.9417+19.012X-0.4214X 2; S L =-107.2795+18.0815X-0.4043X 2; S P = -106.0318 +17.7372X-0.3845X 2; E=-45.1027+455.5003X-9.3504X 2 and I=-1757.318+ 176.7659X -3.6656X 2, respectively. The instrinsic capacity of increase ( r m ) was the highest at 25 ℃ ( r m = 0.1353 ), followed by that at 21 ℃ ( r m =0.1306). As a result, the most favourable temperature for the development was fixed to be ranged from 21 ℃ to 25 ℃. Higher temperatures were unfavorable for the living of this insect. At 35 ℃, survival rate at each stage and egg laying of the adults declined sharply.