Survey on Trichogramma Population in Summer Corn Fields in Jiaodong Area of Shandong Province

Dai Xiaoyan; Wang Yu; Wang Ruijuan; Yin Zhenjuan; Sun Zuowen; Meng Lulu; Zhang Qian; Zhang Hui; Chen Hao; Zheng Li; Zhai Yifan

doi:10.14083/j.issn.1001-4942.2026.01.016

Abstract：Trichogramma is a globally recognized highly efficient egg-parasitic natural enemy of Lepidop-tera pests.To clarify the dominant natural enemy population of Ostrinia furnacalis,a major pest in summer corn fields in Jiaodong area,Shandong Province,and to evaluate the field adaptability of commercial Tri-chogramma dendrolimi products in the region,this study was conducted aiming to provide scientific guidance for the release of dominant Trichogramma species to control O.furnacalis.The parasitic ability of three Tri-chogramma species(T.ostriniae,T.chilonis,T.dendrolimi)on O.furnacalis eggs was compared under labo-ratory conditions.Additionally,T.dendrolimi was released twice in 100 hectares of summer corn fields in Ji-mo,Laixi and Pingdu regions of Qingdao.Parasitized O.furnacalis egg masses were collected from the fields,and the species of Trichogramma were identified through molecular analysis after adult emergence.The results revealed that three Trichogramma species could parasitize O.furnacalis eggs under laboratory conditions,and T.ostriniae exhibited the highest parasitism ability,followed by T.chilonis,while T.dendrolimi showed the-lowest.A total of 29 parasitized O.furnacalis egg masses were collected from the three regions,and 26 of which were successfully identified through molecular analysis.Gene sequence BLAST via GenBank revealed three species:15 egg masses were parasitized by T.ostriniae,9by T.chilonis,and 2 by T.dendrolimi.This study demonstrated that in summer corn fields in Jiaodong area,the dominant Trichogramma species parasiti-zing O.furnacalis eggs was T.ostriniae,followed by T.chilonis,while T.dendrolimi showed poor adaptability in this region.These findings could provide valuable technical recommendations for the selection and release of Trichogramma species to effectively control O.furnacalis in summer corn fields in Jiaodong,area.