低温对锈赤扁谷盗不同虫态及其种群的抑制作用

Inhibition Effects of Low Temperature on Different Growth Stages and the Populations of Cryptolestes ferrugineus

以常见的储粮害虫锈赤扁谷盗为研究对象,研究5、10、15、20℃低温对其不同虫态生长发育的影响,分析低温储粮下害虫对粮食的损害情况,观察低温对其种群增长的影响,为低温储粮状态下的害虫防控提供参考。结果表明,5~20℃低温处理30 d后,成虫死亡率均在30%以下;幼虫死亡率在5℃时最高为76.7%,在10、15、20℃下均低于30%。5、10、15、20℃下,幼虫的致死中时分别为21、44、38、49 d,10~20℃的LT 50值为5℃的1.8~2.4倍;卵在5℃和10℃下不能孵化,15℃下无法完成发育历期,20℃下可发育为成虫。低温对害虫种群增长有显著抑制作用,随着温度降低,害虫对粮食的损害程度逐渐减弱,20℃下害虫对粮食损害程度最大。因此,5~20℃低温储粮可以抑制害虫种群的增长,但致死效果较差,仍需采取有效的害虫防控措施,以达到保质控害,保障粮食安全的目的。

The rusty grain beetle,Cryptolestes ferrugineus(Stephens),is the common pest of stored grain.Under low temperature stress,the mortality of different growth stages of Cryptolestes ferrugineus,the impact on population growth of Cryptolestes ferrugineus,and the damage of pests to grain were investigated in this study.The result indicated that the adult mortality was less than 30%after 30 days under low temperature stress(5,10,15,20℃);the highest mortality of larval was 76.7%at 5℃,while the mortality of larval was less than 30%at 10,15 and 20℃.At 5,10,15 and 20℃,the median lethal time of larvae was 21,44,38,49 days,respectively.LT 50 value at 10~20℃was 1.8~2.4 times that at 5℃;eggs could not hatch at 5 and 10℃and could not complete the development cycle at 15℃,whereas they could develop into adults at 20℃.Low temperature significantly inhibited the growth of pest population.The damage of grain caused by pests gradually weakened with the decrease of temperature,so the greatest damage of grain caused by pest was at 20℃.In conclusion,low temperature at 5~20℃for grain storage could inhibit the growth of pest population,but the lethal effect was limited.It is necessary to combine effective pest control measures to achieve the purpose of food quality assurance,pest control and food security.