热浪式连续高温胁迫对小菜蛾幼虫和蛹的影响

模拟高温热浪的温度模式,研究了热浪式连续高温胁迫对小菜蛾(Plutella xylostella)幼虫和蛹的影响。结果表明,高温胁迫时的初始虫态、胁迫温度、胁迫模式及各因子之间的交互作用都可能对小菜蛾3龄幼虫和蛹的羽化率及生殖力有显著影响。小菜蛾3龄幼虫比蛹耐热,蛹更易受到高温危害。虽然小菜蛾较耐高温,但40℃,持续3 d每天8 h(3 d×8 h/d)的高温胁迫下,相比30℃1 d 8 h(1 d×8 h/d),小菜蛾羽化率降低了55.48%。从生殖角度看,蛹经高温胁迫后生殖力显著低于3龄幼虫,3 d持续高温胁迫与1 d高温相比,生殖力降低了48.84%,40℃胁迫相比30℃,生殖力降低了64.32%。持续长时间的高温热浪天气可能会导致小菜蛾种群数量的大幅度减少。

The Effects of Continuous High Temperature Stress on the Larvae and Pupae of Plutella xylostella

The effects of continuous high temperature on the 3rd larvae and pupae of diamondback moth (DBM)(Plutella xylostella) emergence rate and fecundity were conducted by simulating heat waves.The results showed that the initial development stage of heat stress,stress temperature,heat stress patterns and the interaction between these factors all significantly may affect the emergence rate and fecundity of 3rd larvae and pupae.The larvae were more tolerant to the heat stress than the pupae.The pupae were more susceptible to high temperature stress.The emergence rate was decreased by 55.48％ under the stress of successive 3 d 8 h/d of 40 ℃ compared to 1 d 8 h/d.The fecundity of pupae was significantly lower than larvae under high temperature stress;The fecundity of 3 d stress was decreased by 48.84％ compared to 1 d stress and the fecundity of 40 ℃ stress was decreased by 64.32％ compared to 30 ℃ respectively.The heat waves may lead the collapse of the DBM population in the fields.