Eric Mussen

Hollywood movie refer to them as "killer bees."  Ditto, the news media.

"The known natural distribution of Africanized honey bees (AHB) in California is along a line that runs diagonally from northeastern Tulare County to southwestern San Luis Obispo County, then south to Mexico," says Extension apiculturist Eric Mussen of the UC Davis Department of Entomology. "A colony of AHB was found in Madera County following almond pollination, and the agricultural commissioner decided to call the county colonized instead of participating in a delimiting survey.  However, beekeepers in Fresno County are just beginning to report encountering a few more considerably defensive colonies than they used to."

"In southern California, where AHB has been since 1994, they have pretty well filled the basin," Mussen reports. "The last time tests on feral (not human-kept) honey bee colonies and swarms were conducted, AHB were determined to be a little over 80 percent of the totals.  That still may be the case with feral bees in that area, although one would expect a bit lessening of defensive behavior over time, as has happened in Brazil."

But, as Mussen points out, "it took 40 years to reach the point that AHB are not too problematic in Brazil.  We have had them in California only 18 years."

“There’s no way to tell if honey bees are Africanized without DNA testing,” says Mussen, who writes from the UC Apiaries and Bee Briefs on the UC Davis Department of Entomology website.  “They look about the same as the European honey bee.  They tend to be a little darker than European honey bees and a little smaller. What sets them apart is their intensive defensive behavior. They’ve been known to chase their victims a quarter of a mile.”

When beekeepers find intensive defensive behavior in their hives, they kill the queen bee and “requeen” the colony. “Over four to six weeks, the original workers die of old age and the new queen replaces them with more daughters,” Mussen said. 

Africanized honey bees are the result of attempts to hybridize European honey bees (Apis mellifera) with an African race. Researchers brought Tanzanian queen bees (Apis mellifera scutella)  to Brazil in the 1950s.  In 1957, some of the African bee descendants escaped from the researchers and beekeepers and began progressing north.  

The descendants reached southern Texas in 1990 and southern California in 1994. “In California, they were first found “just outside of Blythe, in Riverside County,” Mussen recalls.

“As an area becomes colonized, the Africanized bees will show their true colors—they will exhibit their intense defensive behavior,” says Mussen, an Extension apiculturist since 1976, 

Mussen recommends that anyone working or relaxing in areas known to be colonized by 
Africanized bees “take precautions” by avoiding nesting areas. If the bees start to sting, cover your face with a shirt as you run for a building, vehicle or other shelter, he says. You can also carry an Army surplus gnat/mosquito veil with you to protect your face.

The honey bees’ pheromone, resembling the scent of a banana, sounds the alarm, alerting other bees to attack.

Beekeepers who collect swarms in colonized counties have a “high probability” of hiving an Africanized honey bee colony, Mussen points out, and should always look for unacceptable defensive behavior.

His advice: "It still is not a good idea to collect swarms in southern California and hive them in high human population areas."

“Africanized honey bees are not something to be feared,” Mussen said, “but they are to be respected.”

(Note: Click on this USDA map to see where the Africanized bees are now.)

You can't always choose your tenants.

Sometimes they choose you.

Take the case of our two bee condos, which are blocks of wood drilled with holes for native bee occupancy. One, with the smaller holes, is for leafcutter bees (Megachile spp.) The other, with the larger holes, is for blue orchard bees (Osmia lignaria), fondly known as BOBs.

The leafcutter bees were the first to occupy the bee housing. At one time we had 16 leafcutter bees and one earwig.

The blue orchard bee condo now has three tenants: two BOBs and one spider.

The webweaving spider spun its web and then crawled into the hole for the night to wait for morning.

And to wait for unsuspecting prey.

(Like to learn more about bee condos? See the Harry H. Laidlaw Jr. Honey Bee Research Facility website, UC Davis. Native pollinator specialist Robbin Thorp, emeritus professor of entomology at UC Davis, compiled the list of resources.)

(Editor's note: This event has been postponed until the fall of 2013. Details pending.)

Mark your calenders!

The Honey and Pollination Center at the University of California, Davis, is planning a "Luncheon in the Garden" on Sunday, June 2 from noon to 3 p.m. in the Good Life Garden at the Robert Mondavi Institute for Wine and Food Science on campus.

It promises to be a delightful afternoon.

Executive director Amina Harris says it will be a "dazzling five-course meal from appetizers to cheese and desserts. Each course features honeys from around the globe."

The luncheon, open to the public, supports and introduces the Honey and Pollination Center. Food and drink will be provided by chefs, apiaries, wineries and meaderies (think wine made from honey), and the farmers of California. 

What is the Honey and Pollination Center? Its vision is to establish UC Davis as a global center of excellence and education on bees, honey and pollination.

Its mission:

• Promote the use  of high quality honey in the California market, help ensure the sustainability of honey production in California, and showcase the importance of honey and pollination to the well-being of Californians.
• Spearhead efforts to gain support and assemble teams for research, education and outreach programs for various stakeholder groups including: (1) the beekeeping industry, (2) agricultural interests who depend on bee pollination, (3) backyard beekeepers, and (4) the food industry

Its specific goals are five-fold:

Tickets are $125 per person. Like to attend? Contact events manager Tracy Diesslin at (530) 752-5233 or at tdiesslin@ucdavis.edu.

And if you'd like to make a donation, contact Harris at (530) 754-9301 or aharris@ucdavis.edu.

Meanwhile, be sure to check out the newly created Facebook page.

Claudio Gratton

Claudio Gratton, associate professor in the Department of Entomology, University of Wisconsin, will speak on “Sustainable Bioenergy Landscapes: Can We Balance Our Need for Production and Biodiversity?” at a UC Davis Department of Entomology seminar on Wednesday, April 10.

His seminar will take place from 12:05 to 1 p.m. in Room 1022 of the Life Sciences Addition, corner of Hutchison and Kleiber Hall drives. Katharina Ullmann of the Neal Williams lab is the host. The seminar is scheduled to be recorded for later viewing on UCTV.

“Increasing demands for food, and now fuel, have put pressure on our agricultural lands,” Gratton says. “Land use and land cover are continuing to change the way we manage our lands with significant biological and ecosystem-level consequences.”

 “The ‘simplification’ of the agricultural landscape, that is the removal of natural and semi-natural areas in the landscape and the increase in monocultures of annual crops, is typically associated with a decrease in species richness and increases in crop pest abundance,” he said. “These effects go beyond mere aesthetics.  The consequences of landscape simplification are felt by growers who apply more pesticides in landscapes dominated by annual cropland.  The question then, is can we balance our needs for agricultural production (both food and fuel) in a way that supports other ecosystem services on which we as humans depend?”

“I argue that understanding the relationships between landscape structure and the tradeoffs between ecosystem services will be a key a designing ‘custom’ multifunctional landscapes.”

Gratton, who has a bachelor of science degree in biology from the University of Illinois (1991) and a doctorate in entomology from UC Berkeley (1997),  joined the University of Wisconsin faculty in 2003. His research group works broadly in the field of landscape ecology in both agricultural and natural systems.  In Wisconsin agriculture, he has been interested in understanding how beneficial insects, such as pollinators and lady beetles, utilize the landscape and carry out important functions such as pollination of crops and suppression of insect pests. 

His work in agroecology has included studying insect landscape ecology and conservation in potatoes, rotational grazing, grasslands, soybeans, cranberries and apples. 

Gratton has worked with growers to understand how to best manage non-crop “natural” areas in the landscape in order to enhance and conserve beneficial insects.  He is also an active member of the Great Lakes Bioenergy Research Center as part of the team looking at developing sustainable bioenergy crops.  He teaches courses in insect biological control, multivariate analysis and coastal field ecology.