TY - JOUR
T1 - Responses of two ladybird beetle species (Coleoptera: Coccinellidae) to dietary RNAi
AU - Haller, Simone
AU - Widmer, Franco
AU - Siegfried, Blair D.
AU - Zhuo, Xuguo
AU - Romeis, Jörg
N1 - Funding Information:
We thank Ana Vélez (University of Nebraska, USA), Remo Schmidt (Swiss TPH, Switzerland), and Huipeng Pan (South China Agricultural University, China) for helpful recommendations for the gene expression analysis and Andrew Roberts (Center of Environmental Risk Assessment, Washington, DC) for his critical comments on an earlier draft of the manuscript. We are also grateful to the laboratory of Matthias Erb (University of Bern) for providing D. v. virgifera beetles for RNA extraction, and we thank Heiko Vogel (Max Planck Institute, Germany) for the provision of α-tubulin sequence data from Coccinellidae species.
Publisher Copyright:
© 2019 Society of Chemical Industry
PY - 2019/10/1
Y1 - 2019/10/1
N2 - BACKGROUND: One concern with the adoption of RNAi-based genetically engineered (GE) crops is the potential harm to valued non-target organisms. Species of Coccinellidae (Coleoptera) are important natural enemies and might be exposed to the insecticidal dsRNA produced by the plant. To assess their susceptibility to dietary RNAi, we fed Adalia bipunctata and Coccinella septempunctata with a dsRNA designed to target the vATPase A of the western corn rootworm, Diabrotica virgifera virgifera (Dvv dsRNA). Specific dsRNAs designed to target the vATPase A of the two ladybird beetle species served as positive controls. RESULTS: Our results revealed that both species were sensitive to dietary RNAi when ingesting their own dsRNAs, with C. septempunctata being more sensitive than A. bipunctata. Dvv dsRNA also adversely affected the two ladybird beetles as indicated by a significantly (but marginally) prolonged developmental time for A. bipunctata and a significantly reduced survival rate for C. septempunctata. These results, however, were obtained at Dvv dsRNA concentrations that were orders of magnitude higher than expected to occur in the field. Gene expression analyses confirmed the bioactivity of the dsRNA treatments and the results from the feeding bioassays. These results are consistent with the bioinformatics analyses, which revealed a higher number of 21-nucleotide-long matches, a requirement for effective RNAi, of the Dvv dsRNA with the vATPase A of C. septempunctata (34 matches) than with that of A. bipunctata (six matches). CONCLUSION: Feeding bioassays revealed that two ladybird species are responsive to dietary RNAi. The two species, however, differed in their sensitivity.
AB - BACKGROUND: One concern with the adoption of RNAi-based genetically engineered (GE) crops is the potential harm to valued non-target organisms. Species of Coccinellidae (Coleoptera) are important natural enemies and might be exposed to the insecticidal dsRNA produced by the plant. To assess their susceptibility to dietary RNAi, we fed Adalia bipunctata and Coccinella septempunctata with a dsRNA designed to target the vATPase A of the western corn rootworm, Diabrotica virgifera virgifera (Dvv dsRNA). Specific dsRNAs designed to target the vATPase A of the two ladybird beetle species served as positive controls. RESULTS: Our results revealed that both species were sensitive to dietary RNAi when ingesting their own dsRNAs, with C. septempunctata being more sensitive than A. bipunctata. Dvv dsRNA also adversely affected the two ladybird beetles as indicated by a significantly (but marginally) prolonged developmental time for A. bipunctata and a significantly reduced survival rate for C. septempunctata. These results, however, were obtained at Dvv dsRNA concentrations that were orders of magnitude higher than expected to occur in the field. Gene expression analyses confirmed the bioactivity of the dsRNA treatments and the results from the feeding bioassays. These results are consistent with the bioinformatics analyses, which revealed a higher number of 21-nucleotide-long matches, a requirement for effective RNAi, of the Dvv dsRNA with the vATPase A of C. septempunctata (34 matches) than with that of A. bipunctata (six matches). CONCLUSION: Feeding bioassays revealed that two ladybird species are responsive to dietary RNAi. The two species, however, differed in their sensitivity.
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U2 - 10.1002/ps.5370
DO - 10.1002/ps.5370
M3 - Article
C2 - 30729648
AN - SCOPUS:85063162333
SN - 1526-498X
VL - 75
SP - 2652
EP - 2662
JO - Pest Management Science
JF - Pest Management Science
IS - 10
ER -