What’s the Buzz?

Big changes are awing in the world of bees.

A backyard gardener calls from Burbank to ask a county agricultural official where all the bees have gone.

Another wants to know why he no longer gets many squash or peppers in summer and why there are so few apples on his tree.

Did you see many bees this summer?

One-third of the food on our table comes to us thanks to the pollinating efforts of the common, everyday honeybee, according to Michael Pearson, Los Angeles County’s apiary inspector. But honeybees are in trouble.

“It’s a disaster, actually,” said bee scientist Adrian Wenner, a professor emeritus at UC Santa Barbara.

The honeybee has been hit hard by two predatory mites introduced by accident in the late 1980s. The mites have decimated feral hives. Efforts to protect managed hives, coinciding with changes in tax laws, have made it difficult to commercially keep bees in those little white boxes that used to dot the

landscape.

The result is drastically fewer bees. Stephen Buchmann, researcher with the Forgotten Pollinators Campaign, an Arizona group that is promoting the unsung native bees, says the nationwide population of ordinary honeybees has shrunk from about 5.9 million colonies in 1945 to 1.9 million today.

He and others hope that native bees will replace honeybees as pollinators, and there’s a good chance they might, but native bees are also in a fix: They are finding homes hard to come by in Southern California’s dense neighborhoods.

More likely, Africanized bees--the so-called killer bees--will take the place of honeybees because they are more resistant to the mites. The Africanized bees are in the southeast corner of the state, having started their northward trek after imported African bees escaped from a Brazilian laboratory in 1957.

Honeybees become Africanized when the queens mate with descendants of these escapees. From then on, the progeny are called Africanized. Honeybee colonies are not booted out by new bees, they are simply absorbed and converted by a new hybrid queen.

Although they look very similar to regular honeybees (they are slightly smaller), they are much more aggressive, not liking anyone--people, animals, even leaf blowers--in their neighborhood.

The Advent of Africanized Bees

Although avid gardeners are quite concerned about the disappearance of the honeybee, the arrival of Africanized bees is perhaps of more concern to the average homeowner, especially to those who already fear bees or have allergies. Calling them killer bees--an unfair moniker given the facts--hasn’t helped.

It was predicted that they would be in metropolitan Southern California in 1994, but, according to Pearson, who is also the county’s Africanized bee expert, they’re temporarily stalled in about 10,000 square miles of desert in Imperial County and eastern San Diego and Riverside counties.

Extremely precise maps are being used to track their progress, said Bob Donley with the agricultural commissioner’s office, the county agency keeping track of Africanized bees, and it is expected they’ll get here, sooner or later.

They have already overrun Tucson, where 15% of the wild bee population was Africanized in 1994. The total reached 56% the next year and 90% by 1996. Today, virtually all the honeybees in Tucson are Africanized, except those managed in hives by beekeepers, who routinely check to make sure the queen is not Africanized.

Although swarms of bees have been known to sting a person as many as 1,000 times, it is rare, according to Steven Thoenes, a former U.S. Department of Agriculture bee scientist and owner of BeeMaster Systems, a bee management company in Tucson.

Since the Africanized bees came to town, he said, “people’s lifestyles really haven’t changed that much.”

Although the bees must be respected, they should not be feared. When individuals are out foraging for pollen or water, they are like any other honeybee, docile unless pinched, swatted or stepped on.

Like ordinary honeybees, each can only sting once, and the sting is no more potent than the sting of an ordinary bee, but when the colony becomes large, there are plenty of angry bees to contend with if they become riled.

Established colonies can kill, although incidents are extremely rare. In this country, five deaths are attributed to Africanized bee stings since their arrival in October 1990, two in Texas and three in Arizona.

There have been two incidents in California, both involving tree-trimmers in the Coachella area who ran from the bees; one was stung 25 times before he made his escape.

Africanized bees move, or swarm, more often than ordinary honeybees and people in Tucson are noticing more swarms in their yards. There are about 5,000 swarms each year, according to Thoenes. His company trapped and destroyed more than 500 last April alone.

If promptly removed by professionals, the bees are not a threat. When they are swarming, they are not particularly aggressive, but once they start building a new hive, they become fiercely protective. Even the vibrations and smells from leaf blowers and power mowers (they cannot hear) set them off.

Africanized bees can live in cavities of just about any size, be they curbside meter boxes, attics, even in empty flowerpots, but they need to nest in the protection of a cavity.

When they arrive in the Southland, Pearson suggests, the way to keep them away from your home is to eliminate cavities of all kinds--”to really clean up the yard”--and to cover openings in buildings with 1/8-inch or finer wire mesh.

Government agencies already have plans to deal with them. County vector control agencies will handle calls about swarms, and emergency personal are being trained to deal with stinging incidents. Private pest control companies will do the actual removing of swarms.

The key, Pearson said, will be to report--and stay away from--any “concentrated bee activity” that might suggest a nearby hive. “Run the other way,” he suggested, and get inside a building or vehicle. People can get away from Africanized bees, which fly about 11-12 miles an hour but only defend an area the size of a football field, and then call pest control companies to remove nests.

The Plight of the Honeybee

It is guessed that Africanized bees will replace all of the feral honeybees in time. These are the honeybees that live in the wild, in trees or in walls of buildings and probably visit your garden.

Although they might seem like natives, honeybees were taken from Asia to Europe ages ago, and then to the Americas in the mid 17th century.

The mostly mild-mannered feral honeybees have pollinated many home fruits and vegetables through the years, all of the stone fruits, apples and kiwi fruit, for example, and such vegetables as eggplant, peppers and squash. They are also important pollinators of commercial crops.

Wenner, the retired professor, said they are the “ultimate generalists” and pollinate all sorts of blossoms, from alfalfa to zucchini.

Even if these feral bees aren’t converted by Africanized bees, the wild colonies have been decimated by mites in recent years and could even become extinct (though there have been some recent signs of recovery).

Two types of mites, one called the vampire or varroa mite, introduced by accident in 1988, and one called the tracheal, introduced in 1984, are killing feral bees by the bucketful.

The mites are also having an effect on honeybees kept in commercial hives. The destructive mites can be controlled with special pest strips mounted between frames, but that makes beekeeping more costly. In addition, a subsidy given to bee keepers was recently canceled, increasing costs and reducing incentives.

Many of the bees formerly observed in home gardens probably came from commercial hives. Honeybees can travel several miles and actively forage up to two miles from the hive.

Pearson thinks that beekeeping should be encouraged in towns where it is now discouraged, to increase pollination. “Bees and people can coexist,” he said.

What About Native Bees?

There are many kinds of native bees; about 500 species and sub-species live in Southern California. Entomologist Robbin Thorp, professor emeritus at UC Davis, said at least 100 of these are common in and around gardens in Southern California.

Shiny, solid black carpenter bees and yellow-stripped bumblebees are the biggest and best known of the native bees, but there are many others.

Most, including sweat bees and alkali bees, are solitary bees that do not make colonies; they live in ground burrows. Some live in deep, narrow cavities, like those left by burrowing beetles, including the leaf-cutter bees that make those fascinating circular holes in rose leaves (used to cap either end of their nests).

Casually observed, many look like flies and most are somewhere between the size of a house fly and a honeybee. Often they are dull brown or gray in color. A few have bright metallic, fly-like colors. Most of the females can sting if provoked, though they rarely do.

Some can be very helpful in the garden, pollinating all sorts of fruiting crops. Buchmann, the Arizona researcher, says that native bees are better than honeybees at pollinating some crops, including eggplant and tomatoes.

Bumblebees are so good at pollinating tomatoes, by a method known as “buzz pollination,” that they are being raised to pollinate greenhouse tomatoes. When you hear a high-pitched buzzing, they are shaking pollen out of flowers with their wing muscles. Bumblebees live in small colonies in the ground.

The big, black, carpenter bees are also good pollinators. Occasionally, a lucky gardener will see one of the males, which are dramatically covered with golden hairs.

They get their name by burrowing into soft wood to make their nests. The half-inch-wide holes look like they were drilled with a precision power tool.

Squash, zucchini and pumpkins can be pollinated by squash and gourd bees that came north thousands of years ago along with these crops from Mexico and Central America. These ground-dwelling bees rise very early, often before daybreak, well before the flowers close at mid-morning.

Many native bees are early risers, starting earlier in the season or on cloudy days when no self-respecting honeybee ventures out, one reason they make good pollinators.

Will native bees take the place of the dwindling honeybee? “They probably will,” said Robbin Thorp. “I certainly hope so.’

First they need places to live. In the manicured city or suburban garden, this can be hard to find.

Places Where Bees Can Make Homes

Thorp suggests leaving a little soil uncultivated and bare--some moist, some dry--where native bees can make homes. Retired professor Wenner has left bare dirt between the flagstones in his garden so he can watch their burrowing activities; the bare patches encourage the bees to stay in the garden.

“Most native bees like the kind of place people are always trying to get rid of,” he said--bare ground, dead accumulated brush and the like.

Thorp recommends keeping plenty of flowers in bloom so they have a constant pollen source and limiting the use of pesticide sprays.

“People need to realize that every time they get rid of some pest with sprays, they also get rid of bees,” he said. Bees are very susceptible to many garden sprays.

It takes much longer, several years even, for native bees to rebuild their populations. Native bees reproduce slowly, often producing young only once a year, and the adults die before the young hatch.

With some kinds of leaf-cutting and mason bees, you can try building bee homes or shells that they can then build inside. It’s very simple: Take a chunk of 2x4 or 4x4 and drill holes, with the grain, four to six inches deep. Several diameters of holes work for different bees, according to Thorp. The holes can be spaced rather closely. Put the block of wood on the north side of the house or under eaves, where it is at least partly shaded. Various native bees will line the drilled holes with leaves or mud and move right in.

You can buy this kind of bee house, and even bees to go in it. Entomo-Logic (9807 N.E. 140th St., Bothell, WA 98011-5132, [425] 820-8037) is one of several small suppliers of bee homes and native bees. The homes are pre-drilled blocks of wood that you can hang in the garden. Each has 20 holes, and the holes are lined with little cardboard tubes that can be removed for cleaning. Cost is about $20.

You can also buy the tubes for $1 each, filled with live mason bee larvae. They are shipped in fall and winter and five to seven bees come inside each tube, ready to hatch. According to co-owner Kristina Williams, mason bees are gentle, do not swarm and sting only when swatted.

Mason bees are acknowledged orchard pollinators, even doing their work when ordinary honeybees are fast asleep on cloudy days, one reason they’ve become popular in the apple orchards of Washington state. They also pollinate apples and stone fruits (apricots, peaches and the like) in California, even during wintry weather, which is when blossoms often open.

Better crops on fruit trees this past summer probably had something to do with the sunny spring weather that encouraged early bee activity.

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Bees You Might See

Domesticated honeybees: They seem like natives but were introduced from Europe in the 17th century; they are kept in hives by beekeepers.

Feral honeybees: Escaped from hives, they live in the wild.

Africanized bees: They look like honeybees but have mated with descendants of escaped African bees.

Native bees: These have been here all along and may be big, like a bumblebee, or small, like a sweat bee.

1.) AFRICANIZED HONEYBEE

The buzz: No more harmful than the common honeybee, their aggressiveness is legendary. They are easily infuriated, and a swarm will mass on a perceived danger, delivering hundreds of stings. They are, however, good pollinators.

The look: To the untrained eye, Africanized honeybees look exactly like their European cousins.

The sting: The same as a European’s as long as you are stung only once.

DISTANCE BEES WILL CHASE

European bees: Defend a distance of 350 to 450 yards.

Africanized bees: Defend up to half a mile.

TIME BEES TAKE TO ANGER

European bees: 19 seconds

Africanized bees: 3 seconds

OTHER COMMON BEES

2.) European Honeybee

The buzz: There are several strains of this bee, all valued for their honey and wax production and most of all for their prodigious pollinating. Bees have been domesti-cated since the dawn of agriculture but also exist in the wild. A “true bee” of the Apidae family.

The look: The familiar worker bee has a fuzzy, deep gold striped abdomen.

The sting: Painful but harmless except to sensitive people.

3.) Carpenter Bee

The buzz: This is a big bee of the Anthophoridae family. Its name comes from the tunnels it creates when building a nest, and it’s not picky about the kind of wood it uses; even a telephone pole will do. Carpenter bees are good pollinators, especially of tomatoes.

The look: Up to an inch long, shiny dark blue or black, and sometimes mistaken for the more colorful bumblebee.

The sting: Female delivers a mild sting and is slow to anger.

4.) Leaf-Cutter Bee

The buzz: Tiny member of the Megachilidae family nests mostly in cavities. It trims neat, circular holes in leaves and carries the pulp back to line its nest. Leaf-cutter bees are good general pollinators.

The look: Only a quarter- to-half-inch long and quite hairy.

The sting: Won’t attack, but females can sting; their sting is less painful than a honeybee’s.

5.) Metallic Sweat Bee

The buzz: In the Halictidae family, the house fly-sized bee nests in the ground. Sweat bees are good general pollina-tors, especially of melons.

The look: Just under a half- inch long, with bright green, shiny bodies. Males have striped abdomens.

The sting: If pinched or swatted, females can sting, but the sting is less painful than a honeybee’s.

6.) Bumblebee

The buzz: Another “true bee,” the well-known giant of the garden nests in the ground and feeds its young on pollen and honey. Feared for its size and loud buzz. Excellent pollinator of vegetables, especially tomatoes.

The look: The four local species all have variations on furry yellow and black stripes and are up to an inch long.

The sting: Severe sting, but not easily provoked.

BEE KILLERS

Varroa Mites

Female Actual size: 1.5 mm

Male Actual size: 1.3 mm

Where Mites Are Found

Varroa mites are found in or near bee nests or eggs. Mites eat or infect bee eggs.

Varroa mites are also found between the ventral abdomi-nal segments of the bee or on their backs.

Tracheal Mites

Tracheal mites are found in the airways of the infected bees, causing the bees to suffocate and die.

Honeybee actual sizes:

Worker bee

Drone

Queen bee

BEE BASICS

Compound eye

Simple eye

Head

Middle leg

Hind wing

Fore wing

Antenna

Pollen basket

Hind leg

Claw

Thorax

Abdomen

Stinger

Sources: California Department of Food and Agriculture in San Diego, Los Angeles County Agricultural Commissioner/Weights and Measures; U.S. Department of Agriculture; “Insects of the Los Angeles Basin,” by Charles Leonard Hogue; “A Field Guide to the Insects,” by Donald J. Borror and Richard E. White, bumble bee photo; Tony Rivetti, golden rod image; Wide World photos, main bee; Pedro Iniguez, Web sites