APIS Volume 11, Number 1, January 1993
In this issue
- Mitcur (R) Receives Section Three
- Alternate Disease Treament-Risks Involved
- Resistant Stock--Potentials and Problems
- Can Bees Hear?
- On Bee Bashing
MITICUR (R) RECEIVES SECTION THREE
The product known as Miticur (R) has finally received a section three or general use label. The material is a plastic strip that contains the active ingredient called amitraz. It is labelled to control both Varroa and tracheal mites in bee hives. This material is much needed as an alternative for Varroa mite control using fluvalinate [Apistan (R)] and/or controlling tracheal mites using menthol.
Unfortunately, there have been reports of adverse reactions with the product in Florida and the merchant, a company called Hoechst Roussel, has sent a letter (dated January 15) to those who have purchased Miticur (R) requesting them to temporarily stop treating bees with strips packaged in bags of 300. Instead, these strips should be held until further notice or returned to the point of purchase and traded for those packaged in lots of 30. In an effort to keep communication with beekeepers on this and other issues, the company has established a toll-free number (1-800-723-6516).
On January 20, the Florida Department of Agriculture sent a letter to purchasers of Miticur (R) in which it said:
"Beekeepers who properly document treatment with 1, 2 or 3 Miticur (R) strips will undergo routine post-treatment survey. If less than the recommended 3 strips are used and the post-treatment check shows good control (less than 2 mites per ether roll), the colonies will be certified. If treatment is not effective, further treatment will be required. Because of problems associated with documentation of treatment, the department will not accept one strip as valid treatment. The department cannot guarantee that other states will accept less than the recommended dosage."
Further questions using Miticur (R) in Florida can be directed to Mr. Laurence Cutts, Bureau of Plant and Apiary Inspection, ph 904/372-2505, ext 114 or your local bee inspector.
ALTERNATIVE DISEASE TREATMENTS--RISKS INVOLVED
Dr.Eric Mussen in From the UC Apiaries, University of California, Davis says so-called "alternative" (unregistered and illegal) treatments make little sense to beekeepers. It all boils down to formulation of the product, he says, something companies must spend huge amounts of money developing, testing and registering.
All the components of a pesticide preparation taken as a whole is called the formulation, Dr. Mussen says. Each consists of some amount of pesticide (active ingredient), a carrier and other chemicals (inert ingredients). Both Apistan (R) and Miticur (R) are formulated as 10% pesticide and 90% plastic. Fluvalinate, the active ingredient in Apistan (R), is insoluble in water (not easily absorbed by honey), as is amitraz, the pesticide in Miticur (R). Both are soluble in organic solvents, meaning they are easily absorbed by beeswax.
Other formulations of both fluvalinate and amitraz [for example, Mavrik (R), Taktic (R), etc.] have emulsifiers according to Dr. Mussen. These make both pesticides soluble in water, something necessary for other agricultural applications, but also cause them to be absorbed into honey much more easily. Different formulations may also have "stickers," "spreaders," and various chemicals to help them function effectively on vegetation. None of these specialty chemicals has any tolerance level in honey (both amitraz and fluvalinate do). In addition, these added chemicals may increase the amount of pesticide absorbed by honey, so that established tolerance levels are exceeded.
Dr. Mussen says it's fair to ask whether reducing the cost of formulations to beekeepers would increase sales, producing about the same amount of income over a protracted time period. This would allow the companies to recover developmental and registration costs. He also concludes it's fair to ask beekeepers to stick to registered uses. Using common sense should prevent anybody from using alternative treatments given the known drawbacks. They have been known to kill bees, cause respiratory irritation in applicators and, perhaps worst of all, fail to control target pests.
RESISTANT STOCK--POTENTIALS AND PROBLEMS
I talked to a beekeeper the other day who was treating his colonies with new Miticur (R) strips. I asked him why he was doing so given that the colonies had been treated with Apistan (R) for Varroa mite control last fall. The answer--to control tracheal mites. But, I asked, was there any indication that tracheal mites were problematic? No, but he was treating anyway.
This mindset is troubling. It no longer is standard practice for farmers to routinely spray agricultural fields, something that beekeepers have fought against for many years in the often-in-vain attempt to protect their bees from being poisoned. Instead, many farmers are applying pesticides only when there is a problem and in some cases, only after a specific level of crop damage or pest population has been reached. Regulators and educators have been trying to discourage the practice of "spray and pray," in growers for many years and this effort appears to be working. It hasn't been easy; the real reason many don't routinely spray now is simply because it costs too much. This should be the case with beekeepers as well. When the costs are calculated, it is extremely expensive to chemically treat bee colonies for mites. This practice should always be considered a last, not a first, resort.
We now have two mites that are consuming beekeepers' time and money. One is Varroa jacobsoni, an external parasite, considered to be one of the most damaging pests to honey bees worldwide. Honey bees have little resistance to parasitization by Varroa; it attacks both brood and adults, verifiably affects colonies and can kill them in a few short months. Varroa must be considered dangerous to colonies when found even in low levels. It is prudent to be conservative and treat colonies for this parasite in Florida when there is evidence the bees are infested. Two legal treatments are now available, Apistan (R) and Miticur (R).
Varroa can be determined by visual diagnosis in a number of ways: scanning adult bees, uncapping brood and using chemicals (ether roll, tobacco smoke, acaricides) to dislodge mites from adult bees. For more information on detecting this mite, see VT 249 "Varroa Mite Detection," 1989, IFAS Television. To receive a copy send a blank 1/2" VHS video tape to me at the address below.
Acarapis woodi, the honey bee tracheal mite also causes damage to colonies, but how much and in what way remains controversial. It is difficult to detect and control methods using the one registered chemical, menthol, have met with varying success. With the labelling of Miticur (R), there is now the possibility to treat both Varroa and tracheal mites at the same time. Again, however, it is prudent to determine that mites are first present. Because it is difficult to detect these small, internal mites, there will be more temptation to treat for them "just in case." This is the classic symptom of any agriculturalist who has stepped onto what many have called "the pesticide treadmill." And once one boards the chemical-treatment train, it becomes exceedingly difficult to get off.
The dangers of pesticide dependency are legion. They include: product contamination, environmental pollution and a chemically- resistant pest population. And in a perverse way, chemical control also contributes to a long-range problem while admittedly providing a short-range solution. That's because treatment keeps susceptible bee colonies alive, and in the process, prevents detection of stock that has innate resistance to the pest. The message remains clear: Don't Chemically Treat Unless There is a Reason!
Does the concept of resistant stock hold up under scrutiny? Take a look at chestnuts as reported in the December, 1992 issue of Citrus and Vegetable Magazine. Prior to 1904, the American chestnut was the most important food and timber tree in Eastern U.S. hardwood forests. But a bark fungus, accidentally introduced from the Asia (shades of Varroa also introduced from there), killed some 3.5 billion trees from Maine to Georgia west to the Mississippi River. This largest botanical disaster in history took only 40 years.
According to the article, a James Carpenter discovered a large living American Chestnut in a grove of dying trees in the early 1950s. Budwood from this tree was grafted into rootstock, and in 1962, seedlings were crossed back to both American and Chinese parents. The second generation was moved to Alachua, FL where a grove of some 60 trees can be found that are now over 40 feet tall and 16 inches in diameter. These Dunstan Chestnuts are healthy, vigorous and bear every year. There has not been a single reported infection from the fungus on this variety for more than 30 years.
Fortunately for the beekeeping industry, resistant honey bee stock found in Yugoslavia is now being released to selected queen breeders in the U.S. This is stock ARS-Y-C-1, somewhat resistant to Varroa and considered economically so to tracheal mites. At the present time, a U.S. Department of Agriculture/beekeeping industry stock release panel has been formed. It is seeking Breeder- Propagators with a good deal of experience who will ensure that ARS-Y-C-1 is successfully reared and distributed to beekeepers. For detailed information on becoming a Breeder-Propagator, contact Dr. Thomas E. Rinderer, Research Leader, Baton Rouge Bee Laboratory, 1157 Ben Hur Rd., Baton Rouge, LA 70820, ph 504/766- 6064. The deadline for selection is March 31, 1993.
CAN BEES HEAR?
An intriguing article in the local paper (Gainesville Sun, December 31, 1992) recently described experiments by Dr. William Towne at Kutzdown University in Pennsylvania. He has proven that bees can hear. Although the scientific proof may be Dr. Towne's, beekeepers always figured bees could hear based on the practice of "tanging," making a loud clanging noise which was thought to make swarms stop and cluster. This notion has now been discredited by most authorities, but the tradition no doubt continues .
According to Dr. Towne, bees were considered deaf because they were only tested with loud sounds which produced high pressures. Yes, people could hear them, but honey bees don't hear like humans. Whereas we have a pressure sensitive membrane (ear drum) which is stretched over a closed cavity, the honey bee relies on particle movement. Thus, they hear things only in the near field, very close to the source.
Dr. Towne and a colleague in Germany (Wolfgang Kirchner) trained bees to come to a two-sided sugar-water feeder based on tones emitted from a speaker. When the frequencies were the same (250 cycles per second) as the bee's famed waggle dance, about B below middle C on the piano, the insects consistently responded. According to Dr. Towne, bees clearly can tell the lowest sounds from the highest; they also distinguish mid-range tones from higher and lower ones.
The next step is to search for the honey bee's ear. In this quest, Dr. Towne has taken to applying drops of glue to various honey bee structures. The glue does not hurt the bees. This attempt to "deafen" bees has met with variable results, and for Dr. Towne, the question has become more and more intriguing. He concludes: "I guess I'll have to train a few more bees to find out for sure..."
ON BEE BASHING
Bee bashing by politicians and others is on the rise. The source of all the commotion is the honey loan program, which most writers refer to as a "subsidy." First there was a prime-time television program on the issue, then an article in the Wall Street Journal. Next syndicated columnist George Will got into the act and later a colleague pinned an editorial cartoon on my door showing a fictitious bureau of U.S. Government Investments listing the savings and loan scandal, war on drugs, house post office as being sold to Mr. and Mrs. Taxpayer. In the background, a man on the telephone is saying: "The beekeepers need another $100 million? Is that all?"
Where all this is going is difficult to say. However, in the July- August, 1992 issue of Honey Producer Magazine, Representative C. Stenholm of Texas thanked his colleagues for not passing the Silvio Conte memorial amendment (Mr. Conte, who recently died, was one of the Congress' most virulent antagonists to the honey loan program). This would have eliminated, Mr. Stenholm indicated, the honey loan program over which many have droned on late into the night and which cost to the U.S. government has been reduced from $100 million to $6 million. This seemed to spite the Clinton campaign's idea that bees would go on making honey if the subsidy was eliminated or Mr. Will's silliness about almonds deprived of honey bee pollination: "Soon airline passengers will not get those little packages of nuts. Gosh."
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
