Grubs might not be everyone's idea of a tasty meal but in parts of Central Africa they provide a vital, local source of protein and minerals.

However, as the demand for the critters grows, so do the prices. And there is an environmental impact. Palm weevil grubs live in raffia palms which are being cut down in large numbers.

Now, scientists in Cameroon say they have come up with a solution that not only protects the environment but increases production of the grubs at the same time.

The BBC's Tamasin Ford went to investigate.