Cyanogenic white clover as a proxy for GM biosafety testing using two New Zealand native insects

Concern about the environmental biosafety of transgenic plants could be mitigated by the development of robust testing methods and selection of appropriate non-target (NT) test species. White clover (Trifolium repens L.) plants with either high or low hydrogen cyanide (HCN) levels were used as surrogate transgenic insecticidal and control plants, respectively. Survival, feeding, larval weight and fecundity of two grassland-dwelling native insects, Nicaeana cervina Broun (Coleoptera: Curculionidae) and Zizina oxleyi Felder & Felder (Lepidoptera: Lycaenidae), exposed to these plants were measured. For one of four assessments, Z. oxleyi survival and larval weight was higher on high HCN plants. However, larval weight and developmental time was consistently lower for offspring of one of three parent butterflies irrespective of treatment. Weevil feeding was reduced on high HCN plants. Both test insect species were considered suitable for biosafety assays with genetically modified white clover, and the importance of considering genotype of test insects is discussed.