According to several scientific studies, three-quarters of all insects have disappeared in the last 30 years. To counter this decline, scientists from 13 countries are collaborating on a new approach within the AGRI4POL project. Unlike agri-environmental management, the researchers aim to make crops, rather than the environment, more attractive to pollinators such as wild bees and butterflies. "In doing so, we aim for a win-win situation for both farmers and insects," says research associate Andries Temme from Wageningen University & Research.
Eighty per cent of agricultural crops and one-third of agricultural production depend on pollinating insects. "Yet plant breeders have often ignored the attractiveness of flowers to pollinators," says Temme. "As a result, insects prefer wildflowers over crops in agricultural and horticultural sectors, and those wildflowers are becoming scarcer."
Causes of insect decline
That is just one of the reasons for the decline in insects, explains ecologist Thijs Fijen from Wageningen University & Research. "There are fewer natural habitats and what remains is less diverse and often not connected to other natural areas. Furthermore, excess nitrogen and the use of insecticides also play a role."
Another major cause is the large-scale cultivation of a single crop, or monoculture. "This creates a one-sided food supply for pollinators and a lack of suitable nesting sites, making it difficult for them to survive and reproduce in agricultural areas. This not only leads to unbalanced ecosystems, but also reduces the yields of crops that depend on insects for pollination."
Project targets
To address these challenges, the AGRI4POL project focuses on improving the attractiveness of crops to pollinators. The scientists want to bring about change across Europe. Agricultural crops should no longer have a negative impact on insect numbers but rather contribute to their recovery.
"We see differences in attractiveness between varieties of the same crops, but we don't yet know exactly why that is," Fijen says. "Is it because of the amount of nectar? The proteins in the pollen? The volatiles with which flowers lure pollinators? Or perhaps visual cues, such as UV stripes on petals, guiding insects where to go? We intend to explore all these elements."
"The knowledge we acquire can be used to adapt existing varieties of crops or develop new ones. The goal here is to create a level playing field for both pollinators and farmers, where crops are attractive to pollinating insects and farmers benefit from higher yields and higher-quality harvests," says Temme.
Focus on sunflowers and field beans
Within AGRI4POL, researchers from Wageningen University & Research and their French colleagues are focusing mainly on sunflowers and broad beans. "In France, we are conducting extensive trials in which cameras record how many insects, and which species, visit different varieties. We then use artificial intelligence to analyse these images. This represents an entirely new approach to studying cultivated crops," Temme explains.
A different view of agriculture
The next step is to use the most attractive varieties. This also requires a different view of agriculture. "For example, you can combine various varieties of the same crop, or even multiple crops, to extend the flowering period. For a successful approach, you need to look at the entire cultivation system," says Fijen. Temme highlights the potential benefits for the farmer: "Sunflowers and broad beans both benefit from better pollination. This can ensure higher yields and reduce the risk of pollinator shortages."
"The new approach is an important step towards promoting biodiversity and offers an opportunity to reverse the negative trend into a positive one, where farmers and nature reinforce each other," concludes Fijen.
