Multitrophic interactions involving genetically modified potatoes, nontarget aphids, natural enemies and...

Area of Science:

• Agricultural Science
• Entomology
• Genetics

Background:

• Genetically modified (GM) potatoes expressing cystatin offer a novel approach to managing plant parasitic nematodes.
• Assessing the ecological impact of GM crops on non-target organisms, particularly natural enemies of pests, is crucial for sustainable agriculture.

Purpose of the Study:

• To evaluate the impact of GM potatoes expressing a cysteine proteinase inhibitor (cystatin) on natural enemies of non-target insects, specifically aphids.
• To compare the effects of GM plants, nematicide-treated plants, and untreated control plants on aphid populations and their natural enemies.

Main Methods:

• A field trial was conducted comparing GM potatoes, nematicide-treated control potatoes, and untreated control potatoes.
• Non-target aphid density and quality as hosts for natural enemies were monitored.
• Aphid size, parasitoid fitness (Aphidius ervi, Aspahes vulgaris), and offspring sex ratios were assessed.

Main Results:

• Nematicide treatment significantly reduced aphid density and natural enemy populations.
• GM potatoes and untreated control plants supported similar numbers of aphids and their predators.
• Parasitoid fitness and sex ratios were not negatively affected by aphids feeding on GM plants, and the transgene product was undetectable in field-collected aphids.

Conclusions:

• Transgenic nematode resistance in potatoes appears compatible with biological aphid control.
• GM potatoes offer a potentially more environmentally friendly alternative to nematicides for nematode management.
• The study indicates minimal secondary exposure of natural enemies to the transgene product, supporting the safety of GM crops for integrated pest management.