Early bloom in Rogue Valley too early for many bees

Of the Mail Tribune

MEDFORD — Warm weather has triggered a Rogue Valley fruit tree bloom that has come too early for many bees.

Wild bee populations die back in winter, and many newly hatched bees aren't old enough yet to fly about gathering nectar and pollen, said Sarah Red-Laird, founder and executive director of the Ashland-based Bee Girl organization, which promotes honeybee conservation and educates beekeepers.

“Bees just aren't quite ready to capitalize on this bloom,” she said.

Meanwhile, many commercial beekeepers have their insects in California pollinating almond trees, which usually bloom early. Southern Oregon orchardists, including pear growers, are scrambling for commercially kept bees to pollinate their trees, which flowered early during recent unseasonably warm temperatures.

“Pear growers are calling. We'll get our bees back as quickly as we can to pears,” said John Jacob, a commercial beekeeper and founder of Old Sol Apiaries, based in the town of Rogue River.

He went down to California on Thursday to retrieve his bees from almond orchards and bring them back for Rogue Valley orchards.

To get his bees ready to pollinate early-blooming almond trees, Jacob feeds them pollen substitute patties each year. That triggers earlier reproduction so his company will have enough bees to meet the demand in California.

Commercially kept bees come back from the almond orchards with their colony numbers boosted by nutritious nut tree flowers. Usually Jacob takes them to holding yards and splits the colonies apart to discourage swarming, in which bees divide on their own and fly away.

There is typically a two-week gap between the California almond bloom and the Rogue Valley pear bloom. This year, there is no break between the blooms, he said.

Jacob will have to take his bee colonies to the pear orchards and split them in the field, a much harder job than dividing them in holding yards.

“I would never tell a pear grower, ‘No, I can't bring you bees.’ If they need them, we make sure we get them, even if it means more work for us,” he said.

Without commercial bee pollination, pear crop yields could fall by 70 to 90 percent. Almond trees are even more dependent on commercial bee pollination, Jacob said.

In the Rogue Valley, wild bees and hobby beekeepers keep non-commercial bee hive numbers high enough to allow for some orchard pollination, he said.

This year, Red-Laird said, many wild bees are out of sync with the blooms.

About half of wild bees naturally die off during winter. They begin rebuilding their numbers in the spring, she said.

“Wild bees don't overwinter in a huge cluster because they have finite resources in the winter. The ones that don't die cuddle together and try to stay warm,” Red-Laird explained. “This spring came so early and bees haven't had time to catch up with the bloom with the populations they have. The bloom seemed to pop in days and it takes three weeks for bees to go from egg to adult bee.”

Red-Laird said she fears there won't be enough pollen and nectar left for bees to gather once their numbers are back up to full strength.

“I'm really concerned. I'm hoping petal fall doesn't happen before bees are amped up enough,” she said. “I'm worried there won't be enough stuff for them to eat in later spring and summer.”

Rick Hilton, an entomologist and researcher based at the Oregon State University Extension Office in Central Point, said the pear tree bloom came two and a half weeks ahead of normal, which is a significant amount.

This year marks one of the earliest blooms ever, if not the earliest, he said.

The days are not only warm, but many nights have been warmer than normal.

Researchers track the number of “chilling hours” each night. Fruit trees such as apples and pears need cold temperatures to bloom in a uniform fashion, Hilton said.

“In the 25 years we've been keeping records, this is our lowest amount of chilling by a considerable amount,” he said. “The three lowest years of chilling occurred in the last four years, with this year being the lowest.”

Early blooming poses other dangers, including that fruit trees could be hit with frost, Hilton said.

Mild winters can also allow insect pests such as the Oriental fruit moth to survive better, emerge earlier and show increased activity. Caterpillars of the moth damage shoots and fruit, he said.

“We caught our first Oriental fruit moth of the season on Monday,” Hilton said. “That's the earliest I've ever seen.”


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