Two Decades of Varroa, Part I
Bee Culture (October) Vol. 135 (10): 19-21
Dr. Malcolm T. Sanford
I have been informed that my pending visit to
In recent years, there appears to be a resurgence of hobby and sideline beekeeping according to my sources. I have seen corroborating evidence of this by seeing who is in attendance at various association meetings, and have recognized the emergence of two populations of beekeepers, which I characterize as before Varroa (BV) and after Varroa (AV). The AV folks really have no idea of what beekeeping used to be like for us that are in the BV community, and shouldn’t, for the landscape has inalterably changed with introduction of the Varroa mite, except for a few places like Australia.
fugit (el tiempo
vuela) “time flies” as this month (October 2007)
is the twentieth anniversary of the first detection of the Varroa
I wrote the following in the Apis newsletter, then published
“As a first step in attempting to assess the situation, the Commissioner of
Agriculture on the advice of Varroa Mite Task Force
and the Honeybee Technical Council has placed a two-week moratorium on bee and
beekeeping equipment movement. This is
to try to get an idea of the mite's present distribution. Emergency teams made up of
“It is extremely important to ensure that Varroa is not confused with the tracheal honey bee mite (Acarapis woodi), first found in 1985. There has been and continues to be a great deal of controversy about the latter mite which lives in the breathing tubes of bees. It is difficult to find and the damage it inflicts on colonies is a matter of great debate. At present there is no legal chemical control and experiments on a number of aspects of the biology and control of this mite are continuing. Both the general and beekeeping public, however, may think the present mite crisis is a continuation of the tracheal mite affair. THIS IS NOT SO!
“The Asiatic bee mite (Varroa jacobsoni) is another story entirely. There is near unanimous support that it is
potentially the most serious pest ever to threaten
The next month, I reported the following: “On November 9, a Varroa Mite Research Work Group was created, chaired by
Frank Robinson, Secretary- Treasurer of the American Beekeeping Federation and
retired Professor of Apiculture from the
“To address the short-range problem of bee movement around the state, which is a top priority, Drs. Harvey Cromroy, IFAS (University of Florida) and Everett Nickerson (Methods Development, Division of Plant Industry, FADCS) have initiated paperwork which is being assembled in Tallahasee by Jim Downing, FADCS to request a Section 18 Specific Exemption label for the miticide, Amitraz. This is to develop the necessary information on the material's dosage (how much material should be applied and in what manner), efficacy (how many mites are killed during treatment of a colony) and residues (how much miticide might get into bees, honey and wax).
“In conjunction with this effort, Drs. Cromroy and
Nickerson, with the help of Dr. Elton Herbert, Beneficial Insects Laboratory,
In spite of all the regulatory effort noted above, it was too late. The Varroa mite literally was everywhere and no amount of expense or effort would limit its spread. It still remains incredible to me the rapidity of the mite’s spread; it seemed to spring up everywhere once first detected. The above paragraph contained something extremely significant, the beekeeping industry was embarking on a road to chemical treatment. This paradox was not lost in my statement/question in December 1987, “Pesticide Use Inside Beehives?”4:
“Some years ago the above statement would have raised more than a few eyebrows. Many questions by beekeepers each year concern using pesticides to rid colonies of invasions by ants, wasps, wax moths and on rare occasions, beetles. No answers, however, ever indicated pesticides were to be used near colonies, much less inside them. The closest to this was wax moth control which involved fumigating empty supers with pesticides. To most beekeepers, pesticides were an anathema, responsible for killing untold numbers of colonies in agricultural and urban areas, and agriculturalists and mosquito controllers were considered a collective enemy for using them.
“The worm has turned. With detection of the tracheal mite and now Varroa jacobsoni (the Asian honey bee mite), the hue and cry for pesticide use within the hive by beekeepers has reached a crescendo. This irony has not been lost on some of my colleagues, who've been plagued with beekeeper complaints about pesticide use over the years. Not that pesticides don't have a place in control of mites, but the all-too-prevalent view that they are somehow a ‘magic bullet’ which will mean the end of the pest and a return to business as usual is a bit disconcerting.
“This philosophy may come from the experience with Terramycin
®, which is now routinely used as a preventative treatment for American foul
brood (AFB). As successful as this has
been, it has not entirely eliminated the disease. Most bee inspection services are in place
today specifically because American foul brood is still a threat. Hundreds, perhaps thousands, of colonies
nationwide are burned each year to eliminate American foul brood reservoirs. Many beekeepers emphatically state that if
they see a colony with AFB, they immediately destroy it themselves, even in
“It's important to realize that the management system to control AFB did not come about overnight. It is the result of a good deal of learning on the part of beekeepers, scientists and others since the 1920s, when thousands of infested colonies were routinely burned in an effort to control infestation.
“And as effective as it appears to be at present, use of Terramycin® is not without possible future complications which run the gamut from contaminated honey to an antibiotic-resistant bacterium strain. Fortunately, the causative organism, Bacillus larvae (editor’s note: now named Paenibacillus larvae larvae), has not shown resistance to Terramycin®. Routine treatment for American foul brood also means that the line between bees which have some innate resistance to the disease and those that are susceptible becomes fuzzy. Nevertheless, colonies continue to be routinely treated despite proof that resistance to the disease by several mechanisms does exist within some bee populations. Thus, should Paenibacillus larvae larvae eventually become immune to Terramycin®, bee populations which are resistant to AFB might be difficult to find.
“In Varroa control, resistance by mites to
chemicals improperly used and/or applied has already been established,
particularly phenothiazine in
Looking back on these statements reveals how prophetic they were. The beekeeping community adroitly clambered
aboard what many have called the “pesticide treadmill” in a futile effort to
find a “magic bullet” for Varroa control. The first candidate was quickly approved by
the authorities on an emergency basis, using Mavrik®
(active ingredient fluvalinate) soaked on plywood
strips. I had first seen this technology
On March 21, 1988, it became no longer legal to use fluvalinate-treated wood sticks. Instead, only plastic strips manufactured to slowly release small quantities of fluvalinate, were legal and had to be used under an emergency compliance agreement with the Division of Plant Industry. Apistan® indeed appeared to be a magic treatment and the industry was to get ten good years of use from this material.
The use of Apistan® did not fully alleviate the fears of many that honey could be contaminated by fluvalinate, which might morph into a big problem for the honey market. And it in August of 1990, I wrote the following, “It was only a matter of time. The Boston Herald reported that honey from a specific outfit had been contaminated with fluvalinate, the active ingredient in Zoecon's Apistan® plastic strips. Taking this conclusion further, the newspaper then implied that the contamination came from the strips themselves. The facts do not bear this out, the Corporation says, in a packet of information sent to industry leaders. According to the Corporation, it would take some 96 strips placed into a colony all at once to reach contamination levels reported by the newspaper (1.14 parts per million). If used according to the label, Zoecon points out, honey cannot be contaminated using the strips.
“There are a number of ways that honey might become contaminated with fluvalinate. This
active ingredient, also marketed in other products to control insects on
ornamentals or turf, may be applied to beehives in many ways. Plastic Apistan®
strips can be left in the brood nest too long. It is not legal, nor wise, to leave the strips
in a colony longer than listed on the label. Wax and honey contamination, as well as build
up of resistant mite populations, are the likely outcomes of this practice.
I, therefore, concluded: “The message is clear: all misuse of fluvalinate (that includes at the present time, ANY USE EXCEPT Apistan® strips applied ACCORDING TO THE LABEL accompanying the product) will be sought out by the authorities and is potentially damaging to the beekeeping industry.”5
This sets the scene for the next article on this important historical event