Transgenic crops express Cry proteins exhibit high resistant to target insect pests. When we evaluate the effects
of Cry proteins on the parasitoid of target insect pest via tritrophic experiments (transgenic plant-target insect
pest-parasitoid) host quality of parasitoids might decrease because of insecticidal protein ingestion, this would
cause host-quality mediated effects and influence the accuracy of biosafety assessment. In the current study, high
dose of Cry2Aa protein was injected into the hemolymph of Plodia interpunctella by microinjection, and the
hemolymph was used as the carrier to deliver Cry protein to Habrobracon hebetor, which has been previously
reported as an ectoparasitoid of P. interpunctella larval, in order to avoid the “host-quality mediated effects”.
Results showed that injected Cry2Aa remained at high concentration and bioactive in the hemolymph of P.
interpunctella parasitized by H. hebetor, the hemolymph of P. interpunctella could be used as carriers of Cry protein
to H. hebetor, and high dose of Cry2Aa have no negative impacts on the development time, weight of pupa, sex
ratio, adults weight (male and female), adult longevity and fecundity, and the activity of stress-related enzymes
of H. hebetor. However, the hemolymph of P. interpunctella injected into Galanthus nivalis agglutinin (the positive
control) showed significant negative impact on these parameters measured in the present study of H. hebetor.
This indicated that Cry2Aa protein had no detrimental effects on the biological parameters of H. hebetor measured
in the current study. Meanwhile, this study provides a new method for the safety evaluation of the ectoparasitoids
of target pest and might be expanded to the other species of ectoparasitoids of target insects of Cry
proteins in biosafety risk assessment. |
