Invasive Species Compendium

Detailed coverage of invasive species threatening livelihoods and the environment worldwide

Abstract

The parasitic capability of five Trichogramma species on eggs of fall armyworm Spodoptera frugiperda.

Abstract

Fall Armyworm (FAW), Spodoptera frugiperda, is a polyphagous and migratory pest from the Americas. Since its invasion into China at the beginning of 2019, it has spread to 21 provinces (Autonomous Regions, Municipalities), which might pose a major threat to corn production in China. In order to explore the long-term control system of FAW, we examined the parasitic capacity of five native Trichogramma species on FAW eggs. Furthermore, two Trichogramma species, which performed best against FAW eggs, were reared on FAW eggs for four generations for a possible improvement in performance. The results show that among the tested Trichogramma species, T. dendrolimi had the strongest parasitic capacity on FAW eggs, with an average of 20 parasitized eggs per female wasp, followed by T. bilingensis, which could parasitize 9.6 FAW eggs per female wasp. T. ostriniae could rarely parasitize FAW eggs, with only 1 FAW egg per female wasp. After continuous rearing on FAW eggs for four generations, T. dendrolimi did not show a change in parasitic capacity while T. bilingensis showed an increase in fecundity from 9.6 eggs to 13.4 eggs per female. In summary, the five tested Trichogramma species all can parasitize FAW eggs, and the parasitic capacity of T. dendrolimi and T. bilingensis are better than the others. After multi-generational continuous rearing on FAW eggs, the parasitic capacity of T. bilingensis was improved. Thus, the native Trichogramma also has the potential to control FAW.