The panel of 50 scientists comprising the Task Force on Systemic Pesticides says use of the pesticides should be phased out over time.
But in the meantime they are calling on regulatory bodies to tighten regulations around their use.
Concerns over the use of neonicotinoids and neonics have been raised over the past two decades.
But the panel says the combined study of 800 research papers provides conclusive evidence that the pesticides are causing the mass deaths of bees and butterflies, needed to pollinate most crops.
The study also showed the chemicals pose a significant risk to earthworms and birds and are harming the planet's ecosystem.
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