不同冷藏条件下斜纹夜蛾卵对夜蛾黑卵蜂寄生的影响

Effect of Spodoptera litura Eggs on Parasitism in Telenomus remus Under Different Refrigerated Conditions

【目的】夜蛾黑卵蜂(Telenomus remus)是草地贪夜蛾(Spodoptera frugiperda)的优势卵寄生蜂,而斜纹夜蛾(Spodoptera litura)是繁殖夜蛾黑卵蜂的优良寄主,明确斜纹夜蛾卵冷藏温度、时长对夜蛾黑卵蜂繁殖能力的影响,为草地贪夜蛾的生物防治提供参考。【方法】设置斜纹夜蛾卵不同冷藏温度(4、8、12℃)和冷藏时间(0、3、6、9、12 d),统计其对夜蛾黑卵蜂寄生率、羽化率和雌性率的影响。【结果】斜纹夜蛾卵不同冷藏温度和冷藏时间均能显著影响夜蛾黑卵蜂的寄生率、羽化率和雌性率(P<0.01),且随着斜纹夜蛾卵冷藏温度的下降和冷藏时间的延长,夜蛾黑卵蜂的寄生繁殖指标呈下降趋势。当冷藏温度分别为8℃或12℃、冷藏时间为3d时,夜蛾黑卵蜂寄生率、羽化率和雌性率分别为85.98%、94.71%、56.15%(8℃,3d)和85.49%、94.61%、60.00%(12℃,3d),与对照相比无显著差异(P>0.05),是最适宜的冷藏条件;当冷藏温度为12℃、冷藏时间为6d或9d时,夜蛾黑卵蜂寄生斜纹夜蛾卵受到显著影响(P<0.05),夜蛾黑卵蜂寄生繁殖受到一定影响,但仍可维持种群正常繁殖,可作为备选的冷藏条件。其他冷藏条件对夜蛾黑卵蜂寄生斜纹夜蛾卵有显著影响(P<0.05),不宜作为斜纹夜蛾卵的冷藏条件。【结论】生产上需短期冷藏斜纹夜蛾卵时,可选择冷藏温度8或12℃、冷藏时长3 d;冷藏时间更长时可选择12℃,但不应超过9d。

【Objective】Telenomus remus is the dominant egg parasitoid of Spodoptera frugiperda,and Spodoptera litura is an excellent host for the reproduction of T.remus.The study was conducted to clarify the effects of refrigeration temperature and duration of S.litura eggs on the reproductive ability of T.remus,which would provide references for the biological control of S.frugiperda.【Method】Different refrigeration temperatures(4,8,12℃)and durations(0,3,6,9,12 d)were designed to refrigerate the eggs of S.litura for the parasitism of T.remus,the effects of parasitism rate,emergence rate and female ratio of T.remus were analyzed.【Result】The results showed that both the refrigeration temperature and duration of S.litura eggs could significantly affect the parasitism rate,emergence rate and female ratio of T.remus(P<0.01).Overall,with the decrease of refrigeration temperature and the prolongation of refrigeration duration of S.litura eggs,the parasitic reproduction indicators of T.remus showed a downward trend.The most suitable refrigeration condition were obtained at 8℃or 12℃for 3 d,which had no significant effect on T.remus reproduction compared with the control(P>0.05).The parasitism rate,emergence rate and female ratio of S.litura eggs were 85.98%,94.71%,56.15%(8℃,3 d)and 85.49%,94.61%,60.00%(12℃,3 d),respectively.It had a significant effect on the parasitism of S.litura eggs when the eggs were refrigerated at 12℃for 6 d or 9 d(P<0.05).The parasitism and reproduction of T.remus were affected to a certain extent,but it could still maintain the normal reproduction of the population,which could be used as an alternative refrigeration condition for S.litura eggs.It also had a significant effect on the parasitism of S.litura eggs(P<0.05)when the eggs were refrigerated under other conditions which should not be considered as suitable refrigeration condition for the eggs of S.litura.【Conclusion】For short-term refrigeration,the condition at 8 or 12℃for 3 d is recommended for S.litura eggs;while for longer duration,12℃can be selected,but the refrigeration time should not exceed 9 d.