Researchers found that installing just three bird boxes per hectare led to a 25 per cent reduction in a Dutch nursery's caterpillar population, thanks to the feeding habits of great tits in particular. "You only have to clean the boxes out at the end of the season," said researcher Arjan Smits of Wageningen University, who led the project.
At GrootGroen Plus he was also keen to promote to growers the message that not all insects are bad for the nursery. "Some can be useful in killing nursery pests, but a lot of growers think that, for example, ladybird larvae are harmful," he said. "We give advice on improving living conditions for them, but not for the bad insects."