The antibiotic thread got my attention:  For those of you who missed it,
take a look at the attachment from the pages of APIS or:
 
http://www.ifas.ufl.edu/~mts/apishtm/apis94/apnov94.htm#2
 
Tom Sanford
 
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Malcolm (Tom) Sanford   Extension Apiculturist   University of Florida
Mailing Address:  Bldg 970, Hull Rd., Gainesville, FL 32611-0620
Voice phone  352/392-1801, Ext. 143
FAX  352/392-0190
INTERNET:[log in to unmask]
====================================================================
Publisher of APIS -- http://www.ifas.ufl.edu/~mts/apishtm/apis.htm
Instructor of Principles of Entomology, ENY 3005--
http://www.ifas.ufl.edu/~mts/eny3005/eny3005syl.htm
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http://www.ifas.ufl.edu/~mts/apishtm/apis94/apnov94.htm#2         



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."