【目的】 为明确紫外照射麦蛾卵时最佳杀胚时间。【方法】 在紫外杀胚装置中，设置5-25 min（间隔5 min）的时间，对比不同使用时长的灯管的杀胚效果；设置5-40 min（间隔5 min）的时间，并在距离紫外灯管距离不同的4个位置取样，对比杀胚效果。【结果】 使用时间短的紫外灯管杀胚效果显著好于使用时间长的灯管；紫外照射时间和相对位置对麦蛾卵孵化率有一定的影响，总体上照射时间短，距离远，杀胚效果较差。紫外照射25 min、40 min的孵化率最低，分别为0.63%和0.77%。紫外照射15 min之后各取样位置的卵孵化率差异不显著，最高为6.22%。经紫外线照射的麦蛾卵颜色与正常发育卵相似，会逐渐变为红棕色，但大部分卵不会孵化。【结论】 紫外照射不会立即杀死卵内胚胎；紫外灯管使用一定时间后杀胚效果显著下降；应用本研究中的杀胚装置，处理时间以20-30 min为宜。

[Objectives]  To determine the optimal duration of exposure to UV irradiation necessary to kill Sitotroga cerealella embryos. [Methods]  The lethality to S. cerealella embryos of 5 to 25 min exposure (5 min increments) to ultraviolet light was measured. The effect of exposure durations of 5 to 40 min (5 min increments) and 4 different distances between eggs and UV lamps on hatching rate was also compared. [Results]  The lethality of UV lamps was significantly higher when these were employed for shorter periods of time. Duration of exposure and relative position had significant effects on hatching rate. Overall, the shorter the irradiation time and the greater the distance between eggs and the light source, the lower the embryo mortality rate. The lowest hatching rates, 0.63% and 0.77%, were achieved by irradiating eggs for 25 and 40 min, respectively. Once UV irradiation exceeded 15 min there was no significant change in hatching rate; the highest hatching rate under these conditions was 6.22%. Eggs that had been exposed to UV light were similar in color to control eggs. Like control eggs, they gradually turned reddish-brown but most did not hatch. [Conclusion]  Ultraviolet irradiation does not kill S. cerealella embryos immediately and the lethality of UV lamps decreased significantly after being used for a certain time. The optimal treatment time, using the device developed in this study, is 20-30 min.