Honeybees augment, but don’t replace diverse insect populations
By Summit Voice
FRISCO — With a lot of recent concerns focused on the decline of honeybee populations, a new study shows that wild insects even even more important as pollinators for certain crops for crops stocked routinely with high densities of honey bees, including almonds, blueberries, mangos and watermelons.
“Our study shows that losses of wild insects from agricultural landscapes impact not only our natural heritage but also our agricultural harvests,” said Lucas A. Garibaldi, of the Universidad Nacional de Río Negro – CONICET, Argentina.
“We found that wild insects consistently enhanced the number of flowers setting fruits or seeds for a broad range of crops and agricultural practices on all continents with farmland,” Garibaldi said. “Long term, productive agricultural systems should include habitat for both honey bees and diverse wild insects. Our study prompts for the implementation of more sustainable agricultural practices.”
The study, recently published in Science, focused on understanding whether the ongoing loss of wild insects impacts crop harvest. The researchers compared fields with abundant and diverse wild insects to those with degraded assemblages of wild insects across 600 fields at 41 crop systems on all continents with farmland. In areas where less wild insects visited crop flowers, the proportion of flowers setting seeds or fruits, was considerably lower, they concluded.
The addition of beehives helps improve pollination, but not dramatically. Variation in honey bee abundance improved fruit set in only 14 percent of the crop systems they served.
Wild insects pollinate crops more effectively because an increase in their visitation enhanced fruit set by twice as much as an equivalent increase in honey bee visitation. A high abundance of managed honey bees supplemented — but doesn’t substitute — pollination by wild insects.
“Ecosystem services can depend on biodiversity provided by wild organisms. Intensified agriculture separates crop production and biodiversity,” said co-researcher Alexandra-Maria Klein, of Leuphana University of Lüneburg, Germany.
“Our study shows that this separation can have negative consequences for pollination services not buffered by honeybee management. We urgently need more research that informs but also involves the global and wider society to explore novel management designs for agricultural landscapes.”