Optimized host adaptation to Eri silkworm eggs enhances fitness and biological control efficacy of
Trichogramma ostriniae
against the Asian corn bor
Hang Zhou, Yong‐Ming Chen, Run‐Na Gong, Cheng‐Chao Hu, Haneef Tariq, Adeney de F Bueno, Asad Ali, Lian‐Sheng Zang Abstract
BACKGROUND
To develop a cost‐effective mass‐rearing strategy for Trichogramma ostriniae , a key parasitoid of the Asian corn borer (ACB, Ostrinia furnacalis ), we evaluated the suitability of Eri silkworm (ES, Samia ricini ) eggs as an alternative host to the commonly used rice moth (RM, Corcyra cephalonica ) eggs. Three geographical populations of T. ostriniae [Guizhou (GZ‐To), Shandong (SD‐To) and Jilin (JL‐To)] were assessed on ES eggs under different rearing conditions, including parasitoid‐to‐host ratios (3:1, 5:1, 7:1), parasitization duration (24, 48, 72, 96 h), and female wasp age (0, 1, 2, 3, 4 and 5 days old). In addition, we assessed the parasitic potential of T. ostriniae reared on ES (ES‐To) and RM (RM‐To) to different aged ACB eggs (0, 1 and 2 days old).
RESULTS
All populations were able to parasitize ES eggs, although the GZ‐To population did not show successful emergence. SD‐To exhibited optimal parasitism performance at a wasp‐to‐host ratio of 5:1, but its performance remained significantly inferior to that of JL‐To. JL‐To showed superior performance, particularly at a parasitoid‐to‐host ratio of 3:1 and a parasitization duration of 48 h. Female wasp age significantly affected rearing performance, with 3‐day‐old females exhibiting the highest parasitism rate, emergence rate and offspring production per host egg. Furthermore, ES‐To produced larger adults and demonstrated significantly higher parasitism efficiency against ACB eggs than those of RM‐To, achieving parasitism rates exceeding 80%.
CONCLUSION
The optimal rearing conditions were identified as JL‐To females aged 3 days, a parasitoid‐to‐host ratio of 3:1, and a parasitization duration of 48 h. These findings demonstrate the potential of ES eggs as an effective alternative host for rearing T. ostriniae , offering a practical approach to improve parasitoid quality and enhance biocontrol programs against the ACB. © 2026 Society of Chemical Industry.