Abstract: Telenomus remus Nixon is an important egg parasitoid of noctuid pests and has the potential for the biological control of Spodoptera frugiperda. To improve the production efficiency of mass rearing T. remus using S. litura, the study investigated the effects of host egg age, the deposition time of host eggs, and the wasp-host ratio on parasitism rate and offspring emergence rate of T. remus. The results indicated that the age of S. litura eggs had a significant effect on the emergence rate of T. remus. The offspring emergence rate of T. remus was as high as 90.81% when T. remus mothers parasitized on 1-day-old host eggs, significantly higher than that from 2- and 3-day-old host eggs. The parasitism rate and emergence rate of T. remus were more than 97.5% and 82%, respectively, on S. litura eggs laid by adults within 7 days old, which were higher than those on the eggs laid by females older than 7 days. When the wasp-host ratio was 1:30 or 1:50, T. remus had high parasitism rate and emergence rate, above 99% and 80%, respectively, which were significantly higher than the counterparts from the treatments of wasp-host ratio of 1:70 and 1:100. From the perspective of production efficiency, this study suggests that the 1-day-old eggs laid by S. litura adults within 7 days old can be used for mass rearing of T. remus at a wasp-host ratio of 1:50.

Key words: Telenomus remus, Spodoptera litura, Spodoptera frugiperda, mass rearing