by Larry Powell
|A wild bee on a sunflower. A PinP photo.|
What they found was striking.
|Flea beetles feast on turnip-tops in Manitoba, A PinP photo.|
In both years, pollination by the bees was “the only significant factor” in both fruit set and marketable yield - even when compared to the harm done by the pests. Not only that, the wild bees increased those yields anywhere from one-&-a-half to three times more than honeybees.
So the researchers conclude; If you want better yields, it’s more important to protect the bees that pollinate them than to kill the pests which eat them!
“These data," they state, "advocate for a reprioritization of management, to conserve and protect wild bee pollinations, which could be more critical than avoiding pest damage for ensuring high yields.”
But the lead author of the study, Ashley Leach, is hesitant to extrapolate those findings to other crops like grains and oilseeds, so dominant on the Canadian prairies, for example.
He tells me in an email; "Our findings are intricately linked" to crops reliant on pollination (like seedless watermelon).
"The pest we studied can have a variable effect of yield," Leach told me.
"However, multiple studies have found that insecticides may negatively impact pollinators so any reduction in insecticide spray could potentially impact yield and associated pollinator health outcomes.
"I wouldn’t recommend growers stop applying insecticides unless they don’t see a loss in yield, or they have another pest management practice in place."
The findings are published in the “Proceedings of the Royal Society.”