Presence of Cry1Ab in the Bt maize – aphid (Rhopalosiphum maidis) – ladybeetle (Propylea japonica) system has no adverse effects on insect biological parameters

Abstract

Transgenic Bacillus thuringiensis Berliner (Bt) crops receive particular attention because they carry genes encoding insecticidal proteins that might negatively affect non-target arthropods. Here, laboratory experiments were conducted to evaluate the impact of Cry1Ab-expressing transgenic maize [5422Bt1 (event Bt11) and 5422CBCL (MON810)] on the biological parameters of two non-target arthropods, the aphid Rhopalosiphum maidis (Fitch) (Hemiptera: Aphididae) and its predator the ladybeetle Propylea japonica (Thunberg) (Coleoptera: Coccinellidae). In a long-term assay (three generations), no significant differences were found between R. maidis fed Bt maize and those fed a near-isogenic line (5422) when individual parameters were compared, including nymph development time, adult longevity, aphid spawning period, and fecundity. No negative effects were detected throughout the life cycle of P. japonica in aphids' feeding amount, development (nymphs, pupae, adults, and progeny eggs), fecundity, or egg hatching when they preyed on Bt maize-fed aphids compared with non-Bt maize treatments. A tritrophic assay revealed that Cry1Ab was highly diluted through the food chain (Bt maize leaves, R. maidis, and P. japonica), as detected by an enzymelinked immunosorbent assay (ELISA). In conclusion, although Cry1Ab concentrations in maize leaves increased as the plants developed, Cry1Ab levels were significantly reduced in the aphid R. maidis, and no traces of Cry1Ab were detected in P. japonica preying on Bt maize-fed aphids. The two hybrids of Bt maize expressing Cry1Ab had no negative effects on the measured biological parameters of the aphid R. maidis or its predator, the ladybeetle P. japonica.

Research on Dynamic Assessment System of Composite Fault Risk of Transmission Line Based on Blockchain Energy

“…On the basis of balancing safety and economy, the method of direct buried cable laying shall be minimized. If it is adopted, the cement protection board shall be laid in strict accordance with the construction requirements [25].…”

Expression of Cry1Ab/2Aj Protein in Genetically Engineered Maize Plants and Its Transfer in the Arthropod Food Web

“…Based on their abundance in Chinese maize fields [16], exposure to Cry protein, and suitability for testing under laboratory conditions, the following predators can be suggested as surrogate species: Propylea japonica (Thunberg) (Coleoptera: Coccinellidae), P. fuscipes, C. nipponensis, and spiders. Previous ERA studies have already utilized these species as surrogates, including P. japonica [40][41][42], P. fuscipes [43], C. nipponensis [44], and the spider Ummeliata insecticeps (Bösenberg and Strand) (Aranea: Linyphiidae) [45]. There were some studies on the effect of maize materials containing Cry1Ab/2Aj protein on non-target predators.…”

Decrease in faeces removal and soil bioturbation by dung beetles in genetically modified maize plantations in southern Brazil

“…Toxins produced by Bacillus thuringiensis (Berliner) strains have characteristics that allow the selection of specific targets: Cry I is specific for lepidopterans (Koziel et al, 1993), whereas Cry III targets coleopterans (Herrnstadt et al, 1986). However, their effect on non‐target organisms (NTO) is controversial, showing non‐lethal harmful effects on non‐targets, e.g., changes in development, survival, and behaviour (Delm et al, 1999; Ramirez‐Romero et al, 2008; Lövei et al, 2009; Holderbaum et al, 2015; Alves & Hernández, 2017), or no effects (Naranjo, 2014; Yaqoob et al, 2016; Shu et al, 2019; Singh et al, 2019; Yin et al, 2020).…”