Sublethal effects of the insecticidal fusion protein ω-ACTX-Hv1a/GNA on the parasitoid Eulophus pennicornis via its host Lacanobia oleracea.
BACKGROUND
The neurotoxin peptide ω-ACTX-Hv1a, fused to the carrier molecule GNA, presents potential for insect control as a biopesticide, being orally toxic to insect pests from different orders. However, thorough evaluation is required to assure its safety towards non-target invertebrates. Effects of this novel biopesticide on the parasitoid Eulophus pennicornis via its host Lacanobia oleracea are presented.


RESULTS
Hv1a/GNA did not cause mortality when injected or fed to fifth-stage L. oleracea, but caused up to 39% reduction in mean larval weight (P < 0.05) and increased developmental time when injected. When fed, GNA, but not Hv1a/GNA, caused ∼35% reduction in larval weight, indicating that host quality was not affected by the fusion protein. Although GNA and Hv1a/GNA were internalised by the hosts following ingestion, and thus were available to higher trophic levels, no significant changes in the rate of E. pennicornis parasitism occurred. Number of parasitoid pupae per host, adult emergence and sex ratio were unaffected by GNA- or Hv1a/GNA-treated hosts (P > 0.05). The fusion protein was degraded by parasitoid larvae, rendering it non-toxic.


CONCLUSIONS
Hv1a/GNA has negligible effects on the parasitoid, even under worst-case scenarios. This low toxicity to these insects is of interest in terms of biopesticide specificity and safety to non-target organisms.
Newcastle Institute for Research on Environment and Sustainability, School of Biology, Newcastle University, Newcastle Upon Tyne, UK.|Capes Foundation, Ministry of Education of Brazil, Brasília, Brazil.
Erich Yt
EY
Nakasu
Benaki Phytopathological Institute, Kifissia, Greece.
Filitsa
F
Karamaouna
Benaki Phytopathological Institute, Kifissia, Greece.
Georgios K
GK
Partsinevelos
Newcastle Institute for Research on Environment and Sustainability, School of Biology, Newcastle University, Newcastle Upon Tyne, UK.|Entomology Department, Faculty of Science, Benha University, Benha, Egypt.
Hesham M
HM
Abd El Halim
The Food and Environment Research Agency, Sand Hutton, York, UK.|School of Biological and Biomedical Sciences, Durham University, Durham, UK.
Elaine C
EC
Fitches
School of Biological and Biomedical Sciences, Durham University, Durham, UK.
Prashant
P
Pyati
School of Biological and Biomedical Sciences, Durham University, Durham, UK.
John A
JA
Gatehouse
Newcastle Institute for Research on Environment and Sustainability, School of Biology, Newcastle University, Newcastle Upon Tyne, UK.
Angharad Mr
AM
Gatehouse
Newcastle Institute for Research on Environment and Sustainability, School of Biology, Newcastle University, Newcastle Upon Tyne, UK.
Martin G
MG
Edwards
D000818:Animals; D006790:Host-Parasite Interactions; D007814:Larva / Q000187:drug effects / Q000254:growth & development; D037241:Mannose-Binding Lectins / Q000633:toxicity*; D009036:Moths / Q000187:drug effects / Q000254:growth & development / Q000469:parasitology*; D037121:Plant Lectins / Q000633:toxicity*; D013111:Spider Venoms / Q000633:toxicity*; D014863:Wasps / Q000187:drug effects* / Q000254:growth & development
D037241:Mannose-Binding Lectins; D037121:Plant Lectins; D013111:Spider Venoms; C107148:omega-atracotoxin-HV1; C063117:snowdrop lectin
Eulophus pennicornis; Galanthus nivalis agglutinin; Lacanobia oleracea; fusion protein; non-target organisms; ω-ACTX-Hv1a