The potential of Mythimna sequax Franclemont eggs for the production of Trichogramma spp. after cryopreservation in liquid nitrogen

ABSTRACT The cryopreservation of noctuid eggs in liquid nitrogen has proved be a promising tool in the mass production of Trichogramma, however studies into this technique have only just begun. This study evaluated the response of different densities of the female of Trichogramma pretiosum Riley to the parasitism of Mythimna sequax eggs stored and not stored in liquid nitrogen, and the performance of females reared only in cryopreserved eggs. The study evaluated the influence of the number of T. pretiosum females (4, 8 and 12) released to parasitise 40 M. sequax eggs, stored and not stored for 15 days in liquid nitrogen, as well as the performance of T. pretiosum females reared in eggs stored for three generations and females reared in non-stored eggs. Parasitism by T. pretiosum in stored eggs was 84%, twice the value obtained in previous studies. The emergence of parasitoids was greater than 95% in both experiments. The performance of females raised in stored eggs did not differ from that of females raised in non-stored eggs. The data show that the technique of cryopreservation of M. sequax eggs may be a viable alternative in the mass production of T. pretiosum.

摘要：利用液氮超低温保存夜蛾卵，已被证实是赤眼蜂（Trichogramma）规模化生产中的一种极具应用前景的技术，但目前相关研究尚处于起步阶段。本研究评估了不同密度的广赤眼蜂（Trichogramma pretiosum Riley）雌蜂对经液氮储存及未储存的劳氏粘虫（Mythimna sequax）卵的寄生情况，同时考察了仅以超低温保存卵为寄主饲养的雌蜂的繁育性能。本研究设置了4、8、12头三个梯度的广赤眼蜂雌蜂释放量，以分别寄生40枚经液氮储存15天及未储存的劳氏粘虫卵；同时还对比了以经液氮储存的卵连续饲养三代的广赤眼蜂雌蜂，与以未储存卵饲养的雌蜂的繁育表现。广赤眼蜂对储存卵的寄生率达84%，为既往研究结果的两倍。两组实验中寄生蜂的羽化率均高于95%。以储存卵饲养的雌蜂，其繁育性能与未储存卵饲养的雌蜂并无显著差异。本研究数据表明，劳氏粘虫卵液氮超低温保存技术，可作为广赤眼蜂规模化生产中的一种可行替代方案。