APIS Volume 12, Number 11, November 1994

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APIS

 · 4 Nov 2023

In this issue

• African Bee Found in California
• When Bugs Fight Back:Insect Resistance to Pesticides
• More on Food Labeling for Small Business:USDA Reporting
• A Trip to British Iles- Tracheal Mite and Viruses

AHB IN CALIFORNIA

The African honey bee (AHB) has finally been found in California. The first detection of the migratory front was made 20 miles west of Blythe, in Riverside County. The feral swarm was detected at the Chuckwalla Valley State Prison on a 3-inch pipe on October 24. The prison fire department destroyed the swarm and collected the sample that was later identified by the California Department of Food and Agriculture laboratory as Africanized and confirmed on October 28, by the Agricultural Research Service Bee Laboratory in Beltsville, Maryland.

WHEN BUGS FIGHT BACK

The 1993 winner of the Pulitzer Prize for Explanatory Journalism is Mike Toner of the Atlanta Journal-Constitution. A compendium of his articles has been published under the title "When Bugs Fight Back." This publication is available by contacting the newspaper's automatic marketing service, ph 404/222-88991. It is must reading for anyone interested in agriculture or public health at almost any level.

As Mr. Toner says in his introduction, "the bugs are fighting back and they are getting very good at it." This is strong stuff and Mr. Toner's articles, published between August and April, 1992 give us pause for reflection:

"Like the villains in a late-night horror show, resistant strains of mankind's oldest enemies are finding ways to sabotage our most sophisticated technology. And even the malevolent microbes of 'The Andromeda Strain' or the angry hordes of 'Killer Bees' aren't as scary as the 'superbugs' that are now emerging throughout the world."

Tuberculosis, malaria, pneumonia, and practically every other human infection is now resistant to at least one class of antibiotics, according to Mr. Toner. With reference to insects and weeds, the prognosis is no better. At least 17 'super-insects' are resistant to almost every pesticide. One, the Colorado Potato beetle, can now be killed only using a tractor-pulled blow torch. And in the United Kingdom and Australia farmers are encountering 'mega-weeds' which may threaten the world's wheat supply.

Chemicals have been subverted, Mr. Toner says, unwittingly aided by industries that market them, 'experts' who overuse them, and ordinary people who see them as a promise, for a time, to change the course of evolution. As Dr. Robert Metcalf, University of Illinois concludes:

"The problem is not chemicals; it's the irresponsible way they are used. Our shortsighted and irresponsible use of antibiotics and pesticides is producing strains of monster bugs resistant to nearly everything in our arsenal. The outlook is dismal. And it is getting worse."

Beekeeping, like the rest of agriculture, is increasingly reliant on chemicals. Does this mean there is potential for 'superbugs' to develop? Several potentially devastating problems now under chemical control are candidates. For decades, beekeepers have used and continue to employ the antibiotic, oxytetracycline, as a "preventative" to control American Foulbrood (AFB). It has worked amazingly well; how long it will continue to do so is not known.

Evidence from extended use of antibiotics in humans, however, is not encouraging. Fortunately, for most persons, antibiotics still work, but for some infections, according to Dr. Fred Tenover at the Center for Disease Control, we are close to the end of the road. As quoted by Mr. Toner, he concludes, "The worst-case scenario is almost here. We are very, very close to having bacteria resistant to every significant antibiotic ever developed. Only this time, there are no new drugs coming down the pike."

Physicians can make mistakes in prescribing antibiotics, and many are simply inappropriate for certain conditions, including simple colds and diarrhea, and viral infections. In these cases, not only don't they work, but this use magnifies the possibility of developing resistant bacteria. Another major don't on a list published by the Alliance for the Prudent Use of Antibiotics, quoted in Mr. Toner's work is: "Don't take an antibiotic to prevent a disease you think you have been exposed to. It not only alters the body's normal population of harmless bacteria, but increases your chance of getting a resistant infection."

This last don't is of course what every beekeeper using Terramycin (R) for AFB control does. Unfortunately, it has worked for decades, although there is disturbing evidence from an Argentinean visitor to this department some time ago that AFB in that country has shown resistance to Terramycin (R) in certain areas. I say "unfortunately" because that means that resistance has not shown up in the U.S. in spite of decades of treatments by thousands of beekeepers. Although this is good news if one wants to control the disease, it leads to the belief that this antibiotic is a proverbial "magic bullet" for AFB control. And if this is so, there must be other bullets in our gunslinger's belt which are just as effective for other diseases and pests.

With the introduction of the honey bee tracheal mite (HBTM) and then Varroa, the search for magical cure alls, like that now perceived for AFB, have continued. There appears to be innate resistance against HBTM in certain bee populations; in many areas, it seems that colonies susceptible to this parasite were quickly killed off. Nevertheless, menthol continues to be used as a chemical control in many situations and there is evidence that vegetable oil patties are also helpful.

Varroa is another story. Before this mite was introduced into the U.S., well over 140 different chemicals had been used worldwide to control this parasite. Most didn't work. And only in 1987, when the U.S. was finally infested, was a technology found to effectively kill large numbers of mites and not affect the bees at the same time. This, of course, is the chemical fluvalinate, a synthetic pyrethroid first delivered on wooden strips, then labeled as formulated in the product called Apistan (R). The beekeeping industry could at that time breathe a sigh of relief; a parasite for which the western honey bee (Apis mellifera) has little resistance was now under control. But for how long? Already there is evidence that widespread use (or misuse?) of fluvalinate in Europe may have created resistant mites.

Although there may be other chemicals on the horizon (e.g. formic acid), there is no substitute for wise use of one that is already labeled, legal and effective. Thus, as Mr. Toner suggests: "Whether you're farming the lower 40 or a small garden plot in the back yard, there are things you can do to keep the pests at bay-- and to slow the emergence of resistance:"

Use pesticides sparingly. When you apply pesticide, do so only when there is a problem, not before. (Use the ether roll test, smoke, uncapping brood and washing adults to detect Varroa mites.)

Rotate chemicals. If possible, alternate at least two different classes of compounds--organophosphates, pyrethroids, carbamates or biologicals. [This is not legally possible in the U.S.; in Canada, Apistan (R) can be rotated with formic acid]. Once resistant mites are detected, however, this may not be the best approach.

Avoid persistent pesticides. You run the risk of encouraging resistance even after the problem is gone. [This is potentially the most pernicious problem of all when using fluvalinate. It accumulates over time in wax comb, making the beehive itself a continuous possible source of the chemical, encouraging resistance to develop in mite populations.]

Set up untreated area. Consider providing an untreated area--a refuge of sorts--to preserve a stock of susceptible insects to dilute the effect of resistant genes. [This might be untreated colonies in nearby yards. However, this philosophy runs counter to opinion in the regulatory community that all nearby colonies should be treated to avoid one of the biggest problems posed by Varroa, reinfestation.]

This last is perhaps one of the most interesting new twists developed by Mr. Toner. Providing a "safe haven" for pests, he says, is not a joke. In this way, resistant populations might be diluted by individuals that are not resistant, providing overall better kill rates. This would be, he concludes, something that would have been "anathema" a few years back.

The kill'em all philosophy is a throwback to the time when eradication was the philosophy of choice. But there has been a paradigm shift in pest control. As Dr. Metcalf states, concluding the series "When Bugs Fight Back": "When you try to eradicate an insect, you are going up against a billion years of evolution. Pests have survived that long because they are very good at adapting. We will probably never completely eradicate any pest. We shouldn't be trying. We should be looking for a way to live with them better."

MORE ON SMALL BUSINESS FOOD LABELLING

It was too good to be true. I said in the October, 1994 APIS that nutritional labeling was automatic without notification of either the U.S. Food and Drug Administration (FDA) or Florida Department of Agriculture and Consumer Services. Unfortunately, I was misinformed on this issue. Any business requesting exemption must submit the following information to the FDA:

1. Name and address of business.
2. Name of food product for which exemption is claimed.
3. Average number of full-time equivalent employees from May 8, 1993 to May 7, 1994.
4. Approximate total number of units sold in the U.S. between May 8, 1993 and May 7, 1994.
5. Signature of responsible party; also stating that the person signing will notify the Office of Food Labeling when the product no longer qualifies for exemption.

Send the above to Office of Food Labeling (HSF-150), Center for Food Safety and Applied Nutrition, Food and Drug

Administration, 200 C St. SW, Washington, DC 20204. Questions about this should be directed to Jerad McCowin, special assistant to the director, ph. 202/205-5229.

A TRIP TO THE BRITISH ISLES-TRACHEAL MITES AND VIRUSES

James Bach, Washington state apiarist, recently reported on a trip to the British Isles. It was published in the last edition of the Apiary Inspectors of America Newsletter.Honey Bee Tracheal Mites (HBTM)

1. New Zealand bees are reported to be more susceptible to HBTM during seasons of poor weather; losses of up to 30 percent are seen. The stock is perceived to build up too fast in Spring and has small winter clusters.
2. Local strains are thought to be resistant to HBTM, but losses of 33 percent are still reported. There is no sampling for mites and no treatments given. Colonies are allowed to die; crawling bee symptoms are considered to be due to HBTM.
3. Fifty percent losses in N. Ireland are thought to be from HBTM, complicated by lack of pollen and a long, cold Spring. Beekeepers prefer local queens; few are imported. Both commercial and non- commercial beekeepers let the bees raise their own queens.

Viruses

1. The impact of viruses on bee behavior is not known. Viral surveys of healthy colonies have not been undertaken. Whether the quality of honey bee nutrition has any effect on viruses is unknown.
2. Chronic Paralysis Virus has been known to multiply coincident with HBTM; both organisms prosper under the same conditions. Kashmir bee virus is thought to be the most virulent virus in honey bees.
3. Cell-cleaning bees are nurseries for developing sacbrood virus (SBV). It multiplies in their head (mandibular gland?) Infected bees forage earlier and are primarily nectar gatherers. Nurse bees with SBV quit feeding larvae earlier.
4. Viruses appear to spread when bees remain in the hive for longer than 24-hour periods. Crowded beehives are also conducive to viral spread.

Economics

1. One commercial beekeeper was only breaking even; net profit came from bee-related commodities like tinctures, salves and specialty honeys.
2. Honey prices are soft because of imported honey from China. European beekeepers are actively demonstrating at European Community headquarters to gain support for their interests.

Malcolm T. Sanford
Bldg 970, Box 110620
University of Florida
Gainesville, FL 32611-0620
Phone (904) 392-1801, Ext. 143 FAX: 904-392-0190
INTERNET Address: MTS@GNV.IFAS.UFL.EDU