Effects of Bt soybean on biodiversity are limited to target species and host-specific parasitoids in La Pampa province, Argentina
Bt crops were incorporated in South America more than 20 years ago and their use has increased sharply since then. However, the potential negative environmental effects are still a concern, specifically, the impacts on nontarget arthropod species. The objective of this work was to determine if the e...
| Main Authors: | , , |
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| Format: | info:ar-repo/semantics/artículo |
| Language: | Inglés |
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Ediciones INTA
2024
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| Subjects: | |
| Online Access: | http://hdl.handle.net/20.500.12123/20503 https://doi.org/10.58149/ffkj-7a42 |
| Summary: | Bt crops were incorporated in South America more than 20 years ago and their use has increased sharply since then. However, the potential negative environmental effects are still a concern, specifically, the impacts on nontarget arthropod species. The objective of this work was to determine if the effects of Bt soybean are limited to the removal of the larvae of target Lepidoptera species or if they also indirectly affect the arthropod community. Bt soybean expressing Cry1Ac toxin and non-Bt soybean were planted under the same environmental and agricultural conditions at two planting dates (early and late planting dates). None of the cultivars received insecticide applications. The abundance of phytophagous insects and predatory arthropods was recorded in each treatment (cultivar × planting date). Moreover, the larvae Lepidopteran, stink bugs and eggs of both groups were collected and maintained under controlled rearing conditions to record parasitoids. The diversity of the arthropod assemblage, as well as that of the phytophagous and entomophagous subassemblages of each treatment, and the similarities between them were estimated with and without the presence of target species and their parasitoids. The range-abundance curves were plotted following the same criteria. The diversity was higher in the non-Bt cultivar than in the Bt one. No clear effects of planting date were detected. A high similarity was found among treatments. Our results show that the removal of the target species larvae and their specific parasitoids is sufficient to explain the effect of the Bt soybean on the richness and diversity of the arthropod assemblage as well as those of the phytophagous and entomophagous subassemblages, with no evidence of additional indirect effects on biodiversity. |
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