UC Garden Blogs
Psyllids are small insects that suck plant juices. Few of the over 140 native species of psyllids in California ever cause significant damage to plants. However, about 18 exotic species accidentally introduced from other countries can be pests on...
Foliage distorted by eugenia psyllid
Beekeepers and almond growers are concerned--and rightfully so--about the some 80,000 bee colonies that died this year in the San Joaquin Valley almond orchards. In monetary terms, that's a loss of about $180,000. But the loss isn't just financial. It could have long-term effects.
Beekeepers believe that pesticides killed their bees after the almond pollination season ended but just before they could move their bees to another site. This is a serious blow to both industries. Growers need the bees to pollinate their almonds. Now some beekeepers are vowing this is it; they'll never to return for another almond pollination season.
"When should the colonies be allowed to leave the orchards?" he asks. "When pollination no longer is happening. That does not mean that the bees should remain in place until the last petal falls from the last blossom."
"Why might beekeepers desire to move their hives out of the orchards 'early?' Once the almonds no longer provide nectar and pollen for the bees, the bees find replacement sources of food. Unfortunately, those sources may be contaminated with pesticides that almond growers would never use when the bees are present. Some common pests that surge right near the end of almond bloom include Egyptian alfalfa weevil larvae and aphids in alfalfa, and grape cutworms in vineyards. Delayed dormant sprays sometimes are being applied in other deciduous fruit orchards, even when the trees are in bloom. Often blooming weeds in the crops are attracting honey bees. If the year is really dry, the bees may be attracted to sugary secretions of aphids and other sucking bugs."
Mussen says it's "not difficult to see that accidental bee poisonings often happen. Despite our California regulations requiring beekeepers to be notified of applications of bee-toxic chemicals within a mile of the apiaries, bees fly up to four miles from their hives to find food and water. That is an area of 50 square miles in which they may find clean or contaminated food sources. Thus, growers whose fields are 'nowhere near' any known apiary locations may accidentally kill many bees with chemical applications."
"It seems," Mussen says, "that a combination of exposures of colonies to truly bee-toxic insecticides, followed by delayed effects of exposure to fungicide/IGR mixes during bloom, really set the bees way behind. The problem proved so severe that a number of beekeepers stated that they were never returning to California for almond pollination. That is not a good thing, since we really don't have too many colonies coming to almonds as it is."
In his newsletter, Mussen goes into depth about when and how bees pollinate the almonds and what could be causing the problem and how it can be resolved.
His take-home message? "Our honey bees cannot continue to be exposed to as many toxic agricultural products as they are, or we will not have enough bees to fill the pollination demand for our nuts, fruits, vegetable, forage and seed crops."
That's serious business.
A honey bee packing pollen as it forages on almonds. (Photo by Kathy Keatley Garvey)
Almond growers need bees. Without bees, there would be no almonds. (Photo by Kathy Keatley Garvey)
Could it be--a bee?
Yes, that's the metallic green sweat bee, also called an ultra green sweat bee, Agapostemon texanus. This one (below) is a female. Males and females are easily distinguishable. The female is all green, from head to thorax to abdomen, while the male (right) is green on the head and thorax but not on the abdomen.
Native pollinator specialist Robbin Thorp, emeritus professor of entomology at UC Davis, talked about them at the recent UC Davis Pollinator Gardening Workshop, sponsored by the California Center for Urban Horticulture.
The Agapostemon are members of the Halictinae family. They are "often called sweat bees because in hot weather they are attracted to human perspiration, which they lap up, probably for the salt it contains," according to the book, Bees of the World, by Christopher O'Toole and Christopher Raw.
Some of the family's many genera, including Agapostemon, are restricted to the New World. Halictus and Lasioglossum "are common to the Old and New Worlds," the authors write.
Coreopsis, also called tickseed or coreopsis, is a genus of flowering plants in the family Asteraceae.
We spotted the female metallic green sweat bee at the Loch Lomond Marina, San Rafael. We captured the image of the male several years ago on a seaside daisy at the Mostly Natives Nursery, Tomales.
Green sweat bees will be among the bees featured in the book, "California Bees and Blooms: A Guide for Gardeners and Naturalists," to be published in the fall of 2014 by Heyday Press. It's the work of Gordon Frankie of UC Berkeley; Robbin Thorp of UC Davis; photographer Rollin Coville of the Bay Area; and Barbara Ertter of UC Berkeley. It will contain nearly 30 of the most common bee genera in California.
Frankie, Thorp, Coville and Ertter (and others) also published "Native Bees Are a Rich Natural Resource in Urban California Gardens" in California Agriculture.
Female metallic green sweat bee, Agapostemon texanus, on coreopsis. (Photo by Kathy Keatley Garvey)
Female metallic green sweat bee peers at the photographer. (Photo by Kathy Keatley Garvey)
[From the February 2013 issue of the UC IPM Green Bulletin newsletter] During the last 10 years, a new widow spider has moved into parts of Southern California. The brown widow spider, Latrodectus geometricus, is closely related to the well-known...
You wouldn't know it if you were to visit the two rapini patches in front of the Harry H. Laidlaw Jr. Honey Bee Research Facility on Bee Biology Road, University of California, Davis.
“The bees love the rapini,” said Laidlaw manager and staff research associate Billy Synk, who planted the seeds given him by Project Apis m.
Project apis m., a moniker derived from Apis mellifera, the scientific name of the European honey bee, funds and directs research to enhance the health and vitality of honey bee colonies while improving crop production. It's based in Paso Robles, Calif. Take a look at the organization's website: "We've infused over $2.5 million into bee research since our inception in 2006 to provide growers with healthier bees resulting in better pollination and increased crop yields. We have personal relationships with the nation's commercial beekeepers and with the top bee scientists in the country."
"We fund research studies, purchase equipment for bee labs at our universities, support graduate students and provide scholarships to young bee scientists to encourage their pursuit of science-based solutions to honey bee challenges."
Its eight-member board includes beekeepers and industry leaders. Extension apiculturist Eric Mussen of UC Davis is a longtime scientific advisor.
And rapini? It's a green cruciferous vegetable from the mustard family. The leaves, buds and stems are edible and often served in restaurants throughout the world. If you were in Italy, you'd eat the cimi di rapa or rapini. In Naples, it's known as friarielli and sometimes broccoli di rapa, according to Wikipedia. If you were in Rome, broccoletti. And in Portugal and Spain, grelos.
The bees know it as simply food for their colonies. Good stuff. (In addition to rapini, PAm encourages folks to plant lovers, vetch, allysum, and native wildflowers as bee pasture.)
One thing's for certain: If you plan to participate in the UC Agriculture and Natural Resources' pollinator count for a three-minute period on Thursday, May 8 your eyes will tire from counting all the bees in the rapini!
Like to participate? See the UC ANR's website, Day of Science and Service. You can also photograph pollinators and post the images on the website for all to see and enjoy.
A honey bee foraging on rapini at the Harry H. Laidlaw Jr. Honey Bee Facility. (Photo by Kathy Keatley Garvey)
Honey bee takes a liking to the rapini. (Photo by Kathy Keatley Garvey)
Multi-tasking honey bee cleaning its tongue and packing its pollen load. (Photo by Kathy Keatley Garvey)
A large pollen load. (Photo by Kathy Keatley Garvey)