Rice pollen could be spreading further than previous studies have suggested, thanks to numerous insect species cross-pollinating the crop.

Rice is thought to be mainly self-pollinating. But Xue-xin Chen from Zhejiang University in Hangzhou, China, and his team conducted a two-year survey of rice fields across China and found that hundreds of species of insect visit rice flowers and carry its pollen. These included the European honeybee Apis mellifera, which transported viable pollen grains more than 500 metres from their source. A three-year field study of genetically engineered rice showed that the bees boost gene flow, but that the proportion of unmodified seeds containing the transgene was less than 1%.

These results could have implications for controlling the spread of genes from genetically modified rice varieties.

J. Appl. Ecol. http://doi.org/tfg (2014)