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.