Which is the world’s worst agricultural pest?

They have caused famines that killed millions; they have precipitated the release of hundreds of megatonnes of carbon; they even turned the UK into a nation of tea-drinkers. And today they are still destroying around 40 per cent of the crops that we grow worldwide. Agricultural pests and diseases have a lot to answer for.

So which is the worst? Actually, it’s impossible to say: there are just so many of them, and they are a daily problem for millions of people across the world who depend on what they can grow on their own land to feed themselves and their families.

But the more we know about pests and diseases – where they occur, how they spread, how to recognize them – the more effectively we can target research, plan mitigation strategies, and, most importantly, arm farmers with the knowledge to protect their own crops.

CABI scientists have put together a list of what they consider to be some of the world’s worst pests today, in categories such as Most expensive pest to control and Most imminent threat, and published it on the BBC website.

Have a read. It’s not a definitive list: just the opening remarks in what we hope will be a lively discussion that raises awareness of the serious problems caused by pests and diseases. Please do add your nominations, either here or on the BBC site.

And remember that for millions of subsistence farmers in developing countries, the question about which is the world’s worst agricultural pest is only too easy to answer: it’s the pest that is affecting their livelihoods right now.