Lovely to Look at, but...

May 18, 2011

They're definitely attracted to it.

Honey bees forage furiously on the California buckeye (Aesculus californica).

It's not a good bee plant, though. It's poisonous.

Of California's main bee-poisonous plants--buckeye, death camas (Zigadenus veneosus) corn lily (Veratrum californicam) and locoweed (Astragalus spp.)--the most hazardous to bees because of its wide distribution is the buckeye tree.

Its distribution includes the UC Davis campus. If you walk behind Hoagland Hall, you'll see a thriving buckeye.

And bees and other insects foraging on the blossoms.

"Symptoms of buckeye poisoning usually appear about a week after bees begin working the blossoms," according to the Cooperative Extension booklet, Beekeeping in California, published in 1987 by the UC Division of Agriculture and Natural Resources. "Many young larvae die, giving the brood pattern an irregular appearance. The queen's egg-laying rate decreases or stops, or she may lay only drone eggs; after a few weeks, an increasing number of eggs fail to hatch or a majority of young larvae die before they are three days old."

The booklet, co-authored by six bee experts--five from UC Davis--points out that "Some adults emerge with crippled wings or malformed legs and bodies."

"Foraging bees feeding on buckeye blossoms may have dark, shiny bodies and paralysislike symptoms. Affected colonies may be seriously weakened or may die."

UC Davis Extension apiculturist Eric Mussen edited the publication. Other co-authors were UC Davis entomology professors/apiculturists Norman Gary and Robbin Thorp (both now emeriti); apiculturist Harry H. Laidlaw Jr., UC Davis professor of entomology (deceased); and apiarist Lee Watkins (deceased). Also lending his expertise: Len Foote of the California Department of Food and Agriculture.

If the name Harry H. Laidlaw Jr. sounds familiar, that's because the bee facility on Bee Biology Road, about a mile west of the central campus, carries his name.


By Kathy Keatley Garvey
Author - Communications specialist

Attached Images:

Honey bee foraging on buckeye blossoms. (Photo by Kathy Keatley Garvey)

Honey bee foraging on buckeye blossoms. (Photo by Kathy Keatley Garvey)

California buckeye in bloom behind Hoagland Hall at UC Davis. (Photo by Kathy Keatley Garvey)

California buckeye in bloom behind Hoagland Hall at UC Davis. (Photo by Kathy Keatley Garvey)