Terramycin Powder for Honeybees – Control Foulbrood Disease

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Quick Overview

Terramycin powder is a critical tool for beekeepers in the fight against American Foulbrood (AFB), a devastating bacterial disease caused by Paenibacillus larvae. The disease targets honey bee larvae, leading to colony collapse if not managed. Terramycin, containing Oxytetracycline Hcl, is effective in controlling AFB when used as directed.

This article provides a detailed guide on using Terramycin in powder form. It outlines the various formulations available, including TM25, TM50, and TM100, and the methods of application, such as in syrup or dust form, or through extender patties. The author emphasizes the importance of following the recommended dosages and application frequencies to prevent the development of antibiotic-resistant strains of the bacteria.

I advise beekeepers to combine the use of Terramycin with best beekeeping practices, such as equipment hygiene and barrier management systems, to prevent and contain AFB outbreaks. The article also cautions against the misuse of Terramycin, which can lead to residues in honey and the emergence of resistant bacterial strains. It’s essential to adhere to state and federal regulations when using antibiotics in beekeeping.

While Terramycin is an effective means to control AFB, responsible use under veterinary supervision is crucial to ensure the health of honey bee colonies and the quality of bee products.

About Terramycin Powder

Terramycin powder helps beekeepers control one of the most significant diseases of honey bees – the American foulbrood (AFB) disease. Today, beekeepers have to contend with diseases, and pests as well as state and federal regulations governing the beekeeping industry. This guide takes you through the use of Terramycin in its powder form to help bees weather the disease in the beehive. Beekeeping has become an important agricultural practice raking in millions of dollars each year from sales of honey and other bee products. However, unlike some decades back, establishing and running an apiary is no longer a simple affair. The days when the main concern of us beekeepers was simply establishing honeybee colonies are long gone.

Bacterial Diseases of Honeybees

Bacterial diseases pose a very serious threat to honey bee colonies because they are usually fatal if not treated, and if not controlled will easily wipe out colonies. The American Foulbrood Disease (AFB) is one of the most serious diseases that affect honey bees. It is caused by a spore-forming bacteria referred to as the Paenibacillus larvae. The disease attacks the honey bee larvae when they ingest the spores, which then germinate in the gut and spread quickly to other tissues. Infected honey bee larvae usually die once the cell is sealed. The disease can affect most of the brood, severely weakening the colony and eventually killing it.

Luckily, antibiotic remedies based on the chemical Oxytetracycline hydrochloride (Hcl), are available for the prevention and control of the American Foulbrood disease. One of the antibiotic brands at the fore is Terramycin, which has the active ingredient – Oxytetracycline Hcl and is manufactured by Pfizer™. The drug is able to control American foulbrood when it is applied in the recommended dosages and frequencies for the affected honey bee colony.

Others are Terra-Pro, Tylosin, and Tylan, all of which contain Oxytetracycline as the active ingredient. You should also use best beehive and apiary management practices to prevent infection by Paenibacillus larvae. Various practices such as washing equipment between use in different hives and the implementation of a barrier management system, have helped many beekeepers prevent and contain American foulbrood disease outbreaks.

Control of Diseases in Beekeeping

Dealing with disease and pest infestations are, perhaps, the main challenges beekeepers have to contend with. Diseases and pests, if not controlled, can damage honey bee colonies and in some instances wipe them out completely. In other instances, the products from pest or disease-infested apiaries may not be allowed into the market as they violate state and federal regulations governing the sale and use of such products.

Beekeepers must know and understand the remedies available for the control of diseases and pests in their colonies. Terramycin helps suppress the spread of American Foulbrood disease in the beehive. It prevents the vegetative form of Paenibacillus larvae from thriving in the beehive. However, it does not have any effect on the viability of spores from the bacterium.

What is Terramycin?

Terramycin comes in various formulations including TM25, TM50, and TM100 registered for use in controlling the American Foulbrood Disease. Any of these formulations can be purchased from drug stores with the approval of registered veterinarians, who must have evidence of the disease in the colony.

The TM25 formulation is a water-soluble mixture packed in 0.6-ounce packages with each containing 25 grams of the active ingredient. Another formulation is the TM50, which is not readily water-soluble. It contains 50 grams of the active ingredient per pound. The third formulation referred to as the TM100 contains 100 grams of the active ingredient per pound. This is also not water-soluble.

To treat affected colonies, Terramycin may be applied as a liquid where it is dissolved in sugar to form a syrup feed for the bees. It may also be applied as dust in the blooding chamber of the bee colony and can still be applied through extender patties. Both beginner and experienced beekeepers can use Terramycin to control American foulbrood disease in their apiaries.

Terramycin Powder for Honey Bees

Some Terramycin formulations are water-soluble and can, therefore, be fed directly to bees as a syrup mixture containing the recommended quantity of the active ingredient – Oxytetracycline HCL and a sugar solution. TM25 is readily soluble in water and can be fed directly to honey bees by mixing it into supplemental sugar syrup as feed for the bees as per the manufacturer’s directions. The recommendation is 267 milligrams of the active ingredient per ounce of the solute.

Once the mixture is prepared, it should be bulk-fed using feeder pails, division board feeders, or by filling the combs. A fresh drug/syrup mixture must be prepared for each of the required three applications. The drug/syrup mixture should be fed in the spring or fall and consumed by the bees before the main honey flow begins, in order to avoid contamination of production honey. In all cases, it should be withdrawn at least six weeks before honey flow starts.

Since the manufacture of TM25 has been discontinued by Pfizer™, the alternative is to use Tetroxy HCA-280 which is the same chemical but around ten times stronger. Another formulation that can be used in liquid form to treat the American Foulbrood disease is Terramycin 100R. It is required to dissolve one ounce (200 mg Oxytetracycline) of Terramycin 100R in 5 pounds of sugar syrup. The solution is to be applied thrice at four to five-day intervals per colony. The mixture should be dissolved in a small quantity of water before adding to syrup.

Since TM50 and TM100 are not readily soluble in water and the feed must be used up within 10 days of application to ensure the treatment is effective, it is not recommended to apply these two formulations of Terramycin to a colony using the liquid application method.

Terramycin – Application in Powder Form

The formulations of Terramycin TM25 and TM50 can be mixed with confectioners’ sugar to make a dust mixture that can be applied to honey bee colonies as a control measure for American foulbrood disease infestation. A dosage of 267 milligrams of active ingredient per ounce of the mixture in three applications is recommended. The application should be at done every four to five days for three applications.

For TM25, to produce a dust mixture containing approximately 267 milligrams of the active ingredient, one should mix an entire 6.4 oz. package with 2 pounds of ground sugar. This amount is enough to treat approximately twelve colonies at three dustings per colony. For the TM50 formulation, one should add three ounces of the formulation to two pounds of confectioner’s sugar. This produces enough dust mixture to treat eleven colonies at three dustings of one ounce each.

Though the dust mixture can be applied to the top bars of the frames in any hive body, it is best to dust just above the body that holds the brood. The dust mixture should be at the outer edges of the frames to avoid dropping dust into the brood cluster. Uncapped brood cells must not be dusted as this could kill them. There are reports of the death of larvae attributed to Terramycin dust coming into contact with them.

Application of Terramycin in Extender Patties

For extender patties application, the mixture is prepared by mixing vegetable shortenings, such as Crisco®, sugar, and Terramycin. Four ounces (800 milligrams of Oxytetracycline) is mixed with 165 grams of vegetable shortening and 330 grams of sugar. Once ready, the preparation (patties) is to be placed on the top bars of the brood nest frames at the rate of one patty per colony.

There are distinct advantages to applying Terramycin in extender patties. For one, the use of extender patties in the control of American foulbrood requires only one application and therefore one visit to the apiary. This is advantageous in that the colonies are less disturbed in this manner.

However, it is important to get the patty recipe correct, because large patties are usually not consumed entirely which could result in under-treatment. This can result in a problem with the disease causing Paenibacillus larvae, to become resistant to Terramycin.

There are also indications from recent research that colonies containing extender patties are more attractive to adult small hive beetles than colonies without patties.

Terra-Pro for Honey Bees

It often proves difficult to obtain the right mixture of HCL-280 and sugar. Again, the elaborate recipe for obtaining a tetracycline and powdered sugar mixture for either a dust application or syrup application is also problematic. To avoid many of the possible mistakes and problems encountered when trying to get a uniform mixture, a ready-to-use preparation, the brand name Terra-Pro can be used instead. Terra-Pro, a ready-to-use preparation contains Terramycin™, Bee-Pro®, sucrose, and other vitamins and minerals. Purchasing Terra-Pro requires a Veterinary Feed Directive (VFD) note from a registered veterinarian. Every Terra-Pro package comes with a measuring spoon adding to the ease and convenience for the users.

Terra-Pro should be fed early in the spring and fall and should be consumed by the bees before the main honey flow begins. For spring treatment, 200 milligrams of Terra-Pro (approximately two measuring spoons) should be spread around the edges and ends of brood frames and top bars of the brood chamber.

During the fall, two full measuring spoons of Terra-Pro spread around the whole of the inner cover of the hive are recommended. For both spring and fall, three applications at intervals of four or five days should be followed.

Caution on the Use of Terramycin

Like all antibiotics, the use of Terramycin is controlled by the Food and Drug Administration (FDA) and the states, needing supervision of use by registered veterinarians. To use Terramycin for the control of American foulbrood disease, a licensed veterinarian should examine the colony and diagnose the presence of the spores to prescribe the treatment. The correct application should then be applied under the veterinarian’s supervision to completely eradicate the disease. Otherwise, if the correct dosage and procedures are not followed, strains of the bacteria that are resistant to Oxytetracycline Hcl may develop, further complicating the problem. Already, there is evidence of a strain of Paenibacillus larvae that is resistant to Oxytetracycline Hcl.

Additionally, various states impose their regulations on the use of Terramycin formulations in the control of American foulbrood. In general, the instructions on use by manufacturers and any other regulations imposed by states and other federal regulatory bodies must be followed to the letter.

Another problem likely to arise from the incorrect application of Terramycin is that this may result in chemical residuals remaining in honey. This is why beekeepers must ensure that any treatment(s) must be withdrawn at least six weeks before the main honey flow starts. Honey from colonies treated with Terramycin should not be presented for human consumption.

Apart from using antibiotics, the disease – American foulbrood, can also be controlled by burning infected hives and their colonies completely, to avoid spreading it to healthy colonies through robber bees. Equipment used when working on infested hives should not be used to work on healthy colonies to avoid spreading it.

Hive Hygiene for American FoulBrood Prevention

To keep American foulbrood out of your colonies, it is utterly important to maintain hygiene on the inside of your hives. I advise beekeepers to remove clumps of the old burr combs and propolis as well as replace old combs with a new foundation every two to three years. Furthermore, it is recommended that a state inspector should inspect your beehives and ascertain the status of the colonies as far as American foulbrood disease is concerned. This way, appropriate action will be recommended.


Terramycin, in any of its applications, is an effective drug to control the American foulbrood disease. However, it cannot be used indiscriminately since its use is regulated and again because of the seriousness of the consequences of its misuse. As such, I advise beekeepers to seek professional advice from veterinarians on the use of the drug.

According to most of the regulations and guidelines on the use of Terramycin as a control to American foulbrood, treatments should be applied in the spring or fall and must be used up before the main honey flow begins, irrespective of the method of application. This is to avoid contamination of the production of honey by drug residuals.

Any honey stored during medication periods in combs should be removed following the final medication of the bee colony and should not be used in human food.

All and any uses of the drug Terramycin powder for bees must adhere to state and federal apiary laws and regulations. Since every state has specific regulations relating to disease control and medications, it is important to contact the appropriate official or state departments of agriculture for specific Interstate and Intrastate regulations concerning the use of antibiotics. Care must be taken to ensure that the manufacturer’s instructions are strictly followed. Terramycin powder for bees can be an effective antibiotic remedy for tackling American foulbrood disease as long as it is used as per the manufacturer’s instructions.


What are your thoughts on Terramycin Powder? Leave a comment below and let us know.

About Michael Simmonds

Michael Simmonds is an American beekeeper with more than two decades of experience in beekeeping. His journey with bees began in his youth, sparking a lifelong passion that led him to start his own apiary at the tender age of 15. Throughout the years, Simmonds has refined his beekeeping skills and has accumulated a wealth of knowledge concerning honeybee biology and behavior. Simmonds' early exposure to beekeeping ignited a fascination with these pollinators, influencing his decision to establish BeeKeepClub in 2016. The website was created with the aim to serve as the ultimate resource for beginners interested in beekeeping. Under Simmonds' guidance, BeeKeepClub provides comprehensive information to novices, including the basics of beekeeping, the different types of bees and hives, the selection of hive locations, and the necessary beekeeping equipment. In addition, the site offers detailed reviews of beekeeping tools to help enthusiasts make informed decisions and get the best value for their investment​​. His contributions to the beekeeping community through BeeKeepClub are substantial, offering both educational content and practical advice. The website covers a wide array of topics, from starting an apiary to harvesting honey, all reflecting Simmonds' extensive experience and passion for the field. Simmonds’ approach is hands-on and educational, focusing on the importance of understanding bees and the environment in which they thrive. His work not only guides beginners through their beekeeping journey but also reflects a commitment to the well-being of bees. Michael Simmonds has dedicated a significant part of his life to bees and beekeeping, and through BeeKeepClub, he has made this knowledge accessible to a broader audience. His work undoubtedly embodies a blend of expertise, authority, and trustworthiness in the realm of beekeeping.
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Charles Jewett
Charles Jewett
2 years ago

I’m a commercial BeeKeeper,
How can I order the antibiotic called Terramycin Powder solvable for my honey bees..

Lawrence Rayburn
Lawrence Rayburn
1 year ago

I just wanted to know prices and where to order terramycin for my stock….didn’t need a lecture.

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