Responses of 9 lepidopteran species to Bacillus thuringiensis: How useful is phylogenetic relatedness for selecting surrogate species for nontarget arthropod risk assessment?

Abstract

To evaluate phylogenetic relatedness as a proxy for susceptibility to Bacillus thuringiensis (Bt) when selecting species to act as surrogates for others in prerelease testing, we examined the responses of 11 laboratory-reared lepidopteran colonies, comprising members of 2 families, 5 genera, and 9 species, to a commercial Bt preparation. Survival, pupal mass, and timing of pupation and adult emergence of 2 noctuids (Spodoptera litura and Helicoverpa armigera) and 7 tortricids (Cnephasia jactatana, Ctenopseustis obliquana, Ctenopseustis herana,Planotortrix octo, Planotortrix notophaea,Planotortrix excessana [2 different laboratory colonies], and Epiphyas postvittana [2 colonies]) were examined after feeding first instar larvae with artificial diet containing 5 μL/100 mL Dipel ES (Bt subsp. kurstaki). Bt caused significant larval mortality in all species except S. litura, in which only pupation was delayed compared with untreated controls. Neither of the noctuid species tested would act as a suitable surrogate for the other in tests of Bt impacts on survival. With the exception of the 2 colonies of E. postvittana, which differed from each other not only in their responses to Bt but also in their development times when not treated with Bt, species within each tortricid genus had similar responses to Bt and thus could act as surrogates for each other. Members of different genera within this family could represent each other only if relatively coarse measurement endpoints (e.g., toxic or not) were considered adequate for assessing risks to nontarget species in the field.

Effects of clothianidin on aquatic communities: Evaluating the impacts of lethal and sublethal exposure to neonicotinoids

“…Previous studies have observed phylogenetic relatedness as a predictive factor for toxicity among related species for other contaminants (e.g. endosulfan, zinc, Bacillus thuringiensis toxin) [52–54]. Our results provide support for the notion that phylogenetic relatedness may be useful for predicting toxicity of clothianidin and possibly other neonicotinoids in aquatic invertebrates.…”

Extension of the spatially‐ and temporally‐explicit “briskaR‐NTL” model to assess potential adverse effects of Bt‐maize pollen on non‐target Lepidoptera at landscape level

“…Other recent studies reporting about Bt effects on Lepidoptera larvae were less relevant for the following reasons: they focused on Bt sprays instead of Cry proteins or Cry maize pollen (Burgess et al (2015); they studied lepidopteran pest species instead of non-target species (Erasmus et al 2010(Erasmus et al , 2014Mahmoud et al 2011;Pérez-Hedo et al 2012;Munoz et al 2014); they were done with transgenic crops other than maize (Kjaer et al 2010); they investigated nectar feeding rather than pollen feeding (Paula et al 2014); or they studied exposure rather than direct toxic effects (Lang and Otto 2015;Lövei et al 2020). In total, the literature map includes 25 publications, of which 21 reporting on laboratory experiments with 17 different species, and 6 on field studies with diverse specimens (see Appendix A).…”

Laboratory tests with Lepidoptera to assess non-target effects of Bt maize pollen: analysis of current studies and recommendations for a standardised design

“…However, since 2010, only one further research paper about Bt maize pollen effects on non-target Lepidoptera has been published [6]. Other recent studies reporting on Bt effects on Lepidoptera larvae focused on Bt sprays instead of Cry proteins or Cry maize pollen [13], studied lepidopteran pest species and not non-target species [14][15][16][17][18], were done with transgenic crops other than maize [19], investigated nectar feeding rather than pollen feeding [20], or studied exposure rather than direct toxic effects [21,22].…”