ABSTRACT

Standifer, L. N., Moeller, F. E., Kauffeld, N. M., Herbert, E. W., Jr., and Shimanuki, H.

1977. Supplemental Feeding of Honey Bee Colonies. United States Department of Agriculture Agriculture Information Bulletin No. 413, 8 pages, illus.

This publication discusses the general food requirements of honey bees, Apis mellifera L., and presents formulas for supplementary diets and methods for feeding such foods to bee colonies. In early spring, before pollen and nectar are available or at other times of the year when these materials are not available for bees in the field or in the hive, supplementary feeding may help the colony survive or sustain brood rearing and colony development. None of the protein supplemental foods fed to honey bees is a complete replacement for natural pollen; however, several brewer's yeast products, Wheast, and soybean flour, fed singly or in combination, can be used to improve the nutrition of colonies when natural pollen is scarce. Cane or beet sugar and isomerized corn sirup can be used to supplement the bees' diet of nectar or honey.

KEYWORDS:
Honey bee (Apis mellifera), bees, food requirements, supplementary feeding, nutrition, protein supplements, pollen supplements, pollen substitutes, brood rearing.

Trade names and the names of commercial companies are used in this publication solely to provide specific information. Mention of a trade name or manufacturer does not constitute a guarantee or warranty of the product by the U.S. Department of Agriculture nor an endorsement by the Department over other products mentioned.

CONTENTS

	Page
Introduction	1
Food requirements of the honey bee colony	1
Why honey bees may need supplemental foods	2
Protein supplemental foods for honey bees	3
Feeding protein supplemental foods	4
As a dry mix	4
As a moist cake or candy patty	4
Pollen supplement and pollen substitute diets	5
Preparing and feeding carbohydrate supplemental foods	6
Preparing and feeding sugar sirup	7
Preparing and feeding sugar candy	8
Feeding dry sugar	8
Supplying bees with water	8
References	8

Washington, D.C.
Issued June 1978

This publication contains information on the general food requirements of honey bees, Apis mellifera L.; formulas for supplementary diets; and methods for feeding such foods to bee colonies.

The natural food of the honey bee consists of pollen, nectar or honey, and water. In early spring, before pollen and nectar are available or at other times of the year when these materials are not available for bees in the field or in the hive, supplementary feeding may help the colony survive, or make it more populous so it will produce more honey or be better able to pollinate crops.


FOOD REQUIREMENTS OF THE HONEY BEE COLONY

Honey bees and other insects have no unusual nutritional requirements. They require carbohydrates, proteins, fats, minerals, vitamins, and water for growth, development, maintenance, and reproduction. Nectar and honeydew are the chief sources of supply for carbohydrates in the diet of bees, and pollen furnishes all the other indispensable constituents. Adult bees can survive on carbohydrates (that is, honey or sucrose) and water; however, proteins, lipids or fats, minerals, and vitamins are necessary for growth and development of young bees and in rearing larvae.

Supplemental foods are fed to honey bees to supply the nutritive requirements of colonies in areas and at times when natural food sources (pollen, nectar, or honey) are inadequate or not available. The brood rearing activity and nutritional state of the colony, the quantity and quality of incoming pollen and nectar, and the food reserves in the hive will determine whether the bees need supplemental foods.

In the South, Southwest, and Southeast, where bees may continue low levels of brood rearing in the winter months, they may require more winter food reserves than colonies in the Northern United States that generally cease brood rearing in late September or October. A colony being prepared for winter in the North should have about six combs containing large areas of stored pollen. Colonies in the southern and southwestern regions may not require as much pollen because of the pollen sources that periodically become available to the bees. Colonies in all regions of the United States should have at least 60 to 90 pounds of honey in the fall.

Normal colonies can be stimulated to have larger populations by providing them with adequate supplemental foods. This feeding should be started 6 to 8 weeks in advance of when package bees or queens are to be produced. Overwintered colonies in the Northern States cap be fed supplementary foods early enough to be divided before the major nectar flow or the need for pollination service.

Colonies are usually fed supplemental foods for one or more of the following reasons:

1.	To ensure continued colony development in places and times of shortage of natural pollen and nectar.
2.	To develop colonies with optimum populations in time for nectar flows.
3.	To develop colonies with optimum populations for pollination of crops.
4.	To build up colony populations for autumn and spring division.
5.	To sustain brood rearing and colony development during inclement weather.
6.	To build colonies to high populations for queen and package-bee production.
7.	To maintain colonies and extend the season for high drone populations for queen matings.
8.	To maintain colonies in feedlot situations.
9.	To build up colonies after pesticide losses.
10.	To provide adequate food reserves for overwintering colonies.

The first examination of colonies in late winter or early spring should reveal any need for supplementary feeding. Unless the winter is extremely long, colonies provided with adequate food stores in the autumn may not need supplemental foods in the spring. However, before and after flowers bloom, especially if the weather is unusually cold and rainy, colonies may urgently need supplemental foods for subsistence and continued brood rearing until nectar and pollen collection again becomes adequate. A sudden curtailment of nectar and pollen income when brood rearing activities are in progress often causes the adult bee population in colonies to decline.


Protein Supplemental Foods for Honey Bees

The protein supplemental foods fed to honey bees are usually divided into two classes: (1) Pollen supplements (artificial high-protein diets containing 5 to 25 percent pollen) and (2) pollen substitutes (artificial high-protein diets containing no pollen). None of the protein supplemental foods fed to honey bees is a complete replacement for natural pollen, nor can they be regarded as more than adequate supplements for natural pollens. However, beekeepers can use protein supplemental foods to improve the nutrition of their bees when natural pollen is scarce.

A good protein supplement food for bees is one that they will readily consume and has the quality and quantity of proteins, lipids, vitamins, and minerals required for growth and development of individuals and reproduction of the colony. Several brewer's yeast products,(2) Wheast,(3) and soybean flour,(4) fed singly or in combination, are palatable and contain the essential nutrients required for growth and development of individual bees and reproduction of the colony. The brewer's yeast products and soybean flour used in bee diet formulations presented in this publication can be supplied to bees as a dry mix inside or outside the hive or as a moist cake inside the hive (fig. 1). Bees are unable to collect Wheast in its original dry state because of its large particle size and, therefore, it must be fed as a moist cake inside the hive.

FEEDING PROTEIN SUPPLEMENTAL FOODS

As A Dry Mix

Dry diet formulations containing brewer's yeast or soybean flour can be supplied to bees inside the hive in division board-frame feeders in the broodnest or outside the hive in trays, boxes, tubs, or other open containers during periods of pollen dearth when bees are flying. A dry mix of the pollen substitute diet formulations is prepared by replacing the water with an equivalent amount of sucrose. When water and honey or sirup are available to bees, there is no need to mix sucrose with the pollen supplement dry mix. If the bees do not readily collect or consume the pollen supplement dry mix, however, the addition of a little sugar may stimulate bees to use it. To protect the dry mix diet from rain or dew, the feeding container can be placed in a sheltered place under a roof or under a hive cover, but readily accessible to the bees. Feeding dry mix food preparations to honey bees outside the hive presents several problems of which the beekeeper should be aware. For example, the strongest colonies take the major share of the food whereas the weaker colonies, which may need it most, collect the least amount. Also, if there are neighboring colonies of bees (within a radius of 2 or 3 miles), they may collect some of this food.

FIGURE 1. - Frame feeder for use inside the hive to supply bees with protein moist cakes.

As A Moist Cake or Candy Patty

When a pollen supplement or pollen' substitute diet is supplied to the bees as a moist cake or patty on the frame top bars inside the hive, it should be placed in close proximity to the un-sealed larvae in brood combs where nurse bees will feed on it readily. The hive cover should be removed, and the bees should be smoked down from the top of the frames. Then, the diet cake should be placed directly over the center of the cluster. The top of the cake should be covered with waxed paper to prevent moisture loss (fig. 2). If an inner cover is used, it should be replaced in an inverted position to provide space for the cake.

If the cake or candy patty diets are not fed on the day prepared, they can be held in a cool place for several days or a freezer for several weeks without deterioration or loss of food value.

FIGURE 2. - Protein supplement diet (wrapped in brown waxed paper to prevent excessive loss of moisture) and a supply of water (water-soaked sponge enclosed in clear plastic bag with bee access hole on top) supplied to the colony on the frame top bars.

Brood rearing requires a large amount of sugar (or honey) in addition to protein supplement foods. As consumption of the protein supplement increases, the depletion of honey reserves in the colony also increases. If an adequate reserve of honey is not present in the hive, the colony should be fed a sugar sirup (two parts sugar to one part water) to avert starvation. Beekeepers planning to feed protein supplements in late winter and early spring in the northern regions should leave no less than 90 pounds of honey per colony in October. In the southern and western regions, where bee flight is almost continuous, colonies should have a minimum of 60 pounds of honey and should be checked periodically for brood rearing and food supplies.


POLLEN SUPPLEMENT AND POLLEN SUBSTITUTE DIETS

Pollen supplements are usually more acceptable to bees than are pollen substitutes. Bee-collected pollen releases biostimulant chemicals in the artificial protein food supplement that are attractive to bees and contain other constituents that aid in keeping the supplement moist, soft, and palatable. Pollens used in bee protein supplemental artificial diets should be trapped by the beekeeper from his own colonies to avoid possible transmission of bee disease (fig. 3). Do not use trap pollen from diseased colonies. Pollen intended for use in protein supplemental diets should be stored in a freezer or dried and stored in airtight containers for no more than 2 years.

Pollen supplement diets containing 20 percent or more of either soybean flour or brewer's yeast are highly palatable to bees and have the nutritive requirements for their growth and reproduction. To prepare the pollen supplement diet as moist cakes for feeding inside the hive, first dissolve the pollen pellets in water(5) since they do not readily soften in sugar sirup. Then, stir in the sugar until it dissolves or is well mixed with the pollen. Finally, add the soybean flour, Wheast, or brewer's yeast to the water-pollen-sugar mixture and stir thoroughly. The bulk supplement should be made up into 1-1/2-pound cakes wrapped in waxed paper to prevent moisture loss. One 1-1/2-pound cake given to a colony will usually last 10 to 14 days. The colony should be provided with a new supplement cake before all the previous cake is consumed.

FIGURE 3. - Collecting trapped pollen pellets from a honey bee colony. Pollen trap collection tray is re-moved from back of hive.

Pollen supplement diets can be made from any of the pollen substitute formulations by adding 10 percent by weight of a clean pollen. It may be necessary to increase the amount of water if pollen is added to the diet. Each beekeeper should experiment with the formulations to determine the amount of water necessary. In humid areas, the suggested amount of water may be excessive.

Protein supplement diets provide an excellent medium for feeding medicants to colonies if such materials are needed. All medicants that are presently recommended for the prevention or treatment of brood diseases and Nosema can be fed in protein supplement diets.

The pollen supplement and pollen substitute diets presented in table 1 were formulated and tested at the USDA-SEA Bee Research Laboratory at Tucson, Ariz.; the Bee Management Investigations Laboratory at Madison, Wis.; and the Bioenvironmental Bee Laboratory at Beltsville, Md. The dietary protein sources and formulations are attractive to bees and will support growth and development of emerging bees and brood rearing.

TABLE 1. - Pollen supplement and pollen substitute diets
Protein source	Dry mix	Moist patty
	Parts by weight
Pollen Supplement Formula 1
Soybean flour:pollen (3:1 w/w)(1)	1
Sucrose:water (2:1 w/w)	2
Pollen Supplement Formula 2
Wheast or brewer's yeast:pollen (3:1 w/w)	1
Sucrose:water (6:1 w/w)	2
Pollen Substitute Formula 1
Brewer's yeast	2	3
Sucrose	3	3
		2-1/2
Pollen Substitute Formula 2
Soybean flour	2	3
Sucrose	3	3
Water(2)		2-1/2
Pollen Substitute Formula 3
Wheast		3
Sucrose		3
Water(2)		4
(1) w/w = weight to weight. (2) Add sufficient water to substitute diet mix to form a doughlike consistency.

PREPARING AND FEEDING CARBOHYDRATE SUPPLEMENTAL FOODS

Proper colony management should insure adequate honey reserves, but sometimes carbohydrate supplemental feeding may be necessary. Whenever colonies have little honey reserves, they should be fed. Carbohydrate foods have some value for stimulating queens to begin laying eggs, but no carbohydrate will support sustained egg laying or brood rearing in the absence of pollen or a protein supplementary food.

Honey is, of course, the ideal carbohydrate food for honey bees. It contains about 80-percent sugars, 18- to 19-percent water, traces of pollen, essential oils, tannins, various salts, minerals, and other materials. However, honey from unknown sources should never be fed to bees since it may contain pathogenic organisms (American foulbrood) injurious to bees. Although bees sometimes store honeydew and fruit juices, these are not good carbohydrate winter foods for bees because they contain materials the bees are unable to digest and utilize for either an energy source or growth and development.

Since the bloom of many plant species lasts only a short time, the beekeeper should pay special attention to timing supplemental feeding of his bees. Protein supplementary feeding should begin prior to the bloom for building up overwintered low-population colonies to optimum strength for a specific honey flow or pollination service.


Preparing and Feeding Sugar Sirup

All carbohydrate foods are not equal in nutritive value for bees and some are toxic. Cane or beet sugar (dry or sirup) and isomerized corn sirup are suitable carbohydrate supplement foods for bees.

1. Cane or beet sugar sirup.- Mix one part (spring feeding) or two parts (autumn feeding) of granulated sucrose with one part water (preferably 49º to 66º Centigrade).

2. Isomerized sirup. - Dilute sirup with an equal volume of water for spring feed (1:1 sirup:water, volume to volume).

Queen and package bee producers feed their colonies sugar sirup to stimulate brood rearing for the production of queens and package bees to meet early shipping date schedules.

When package colonies are established on empty combs or comb foundations, they should be fed thick sirup (two parts sugar and one part water) for 2 or 3 weeks. Thin sirup (one part sugar and one part water) should be fed for gorging package bees prior to release into hive equipment.

Almost any leakproof container, such as a trough, tray, pan, or tub, with an adequate surface area may be used to supply sugar sirup outside the hive. Rocks, pieces of wood, Spanish moss, or similar material on which bees can stand while imbibing these materials should be placed in the container. Open feeders should be covered with a roof to protect sirup from rain and other precipitation. Where wild animals or birds become a problem, provisions must be made to keep them out of the feeder.

Sugar sirup can be supplied to bees inside the hive by one of the following methods.

1.	Friction-top pail. - Several such pails can be placed simultaneously on the top bars of the frames over a colony. An empty hive rim should be placed above the combs of the colony to accommodate the pails and the hive cover placed over all.
2.	Combs within the brood chamber. - When some of the combs in the hive are essentially empty, as commonly occurs in the spring, sugar sirup can be poured directly into the cells with a sprinkling can.
3.	Division board feeder.- This is a small box-like container that replaces a comb in the brood nest suitable for feeding sugar sirup to colonies in early spring or late fall.
4.	In a plastic bag feeder. - The bag encloses much of one or two of the frames in the lower or outer edge of the brood nest, and can hold as much as 10 to 15 pounds of sirup. Bees feed from the upper opening, somewhat like they do from a division board feeder.

In commercial operations, where large numbers of colonies are kept at one location, 500- to 1,000-gallon tanks connected to a metal pan (fig. 4) can be used for supplying sugar sirup and water to bees.

When colonies in the Northern States must be fed sugar sirup to augment winter stores, this feeding should be completed by October 1 to
15. In Southern States, feeding sugar sirup in the fall is advisable if stores are low, and, when necessary, feeding should be augmented in January and February.

The following precautionary measures should be taken when feeding sugar sirup to bees: (1) Feed late in the day, (2) disturb the bees as little as possible, and (3) limit the size of the area (entrance) where bees enter and leave the hives.

FIGURE 4. - Metal pan connected to a 1,000-gal tank with 1/4-inch tubing provides a constant supply of water for large numbers of bee colonies. Mechanical floats in pan regulate flow of water from tank. Excelsior on top of wood slats in pan helps prevent bees from drowning. Steel grid on top of pan protects water supply from large animals.

Therapeutic drugs may be incorporated in sirup for treatment and control of bee disease; however, never feed any therapeutic drugs in candy or sirup to a colony during a honey flow or 5 weeks prior to the start of a major honey flow. (Feeding therapeutic drugs in candy or sirup at these times may contaminate the surplus honey with both sugar and the drug.)


Preparing and Feeding Sugar Candy

To prepare cane or beet sugar candy, mix one part granulated sucrose with one part water and heat this mixture until it becomes the thickness of fudge (softball stage). Pour the candy mix on waxed paper and allow it to cool and harden. Feed the candy to bees by placing it on the frame top bars.


Feeding Dry Sugar

As an emergency measure in late winter, when it is too early to feed sugar sirup, bees may be fed dry sugar by placing a pound or two on the inverted inner cover. Some beekeepers increase the feeding space by providing a wooden rim on top of the inner cover. The bees should have access to water while being fed dry sugar.


SUPPLYING BEES WITH WATER

A supply of water should be available to bees at all times. Water is an essential part of the diet of bees, and a lack of it adversely affects their nutrition, physiology, brood rearing, and normal behavior. The beekeeper should anticipate the need for water and present it to the bees in open pans or trays in which floating supports such as wood chips, corks, or plastic sponge are provided.


REFERENCES

(1) DETROY, B. F., and E. R. HARP. 1976.
TRAPPING POLLEN FROM HONEY BEE COLONIES. U.S. Dept. Agr. Prod. Res. Rept. 163, 11 pp.

(2) DIETZ, A. 1975.
NUTRITION OF THE ADULT HONEY BEE. In The Hive and the Honey Bee, chapter V, Dadant and Sons, Hamilton, Ill. 740 pp.

(3) JOHANSSON, T. S. K., and M. P. JOHANSSON. 1976.
FEEDING SUGAR TO BEES: 1. FEEDERS AND SYRUP FEEDING. Bee World 57(4): 137-142.

(4) _________and M. P. JOHANSSON. 1977.
FEEDING SUGAR TO BEES: 3. DRY SUGAR AND CANDY. Bee World 58(2):
49-52.

(5) RIBBANDS, C. R. 1964.
THE BEHAVIOR AND SOCIAL LIFE OF HONEYBEES. Dover Publications, Inc., New York. 352 pp.

(6) SHIMANUKI, H. 1971.
BEEKEEPING IN THE UNITED STATES. U.S. Dept. Agr. Agr. Handbook 335, 174 pp.

(7) STANDIFER, L. N., G. D. WALLER, M. H. HAYDAK, M. D. LEVIN, and J. P. MILLS. 1971.
STIMULATIVE FEEDING OF HONEYBEE COLONIES IN ARIZONA. J. Apic. Res.
10: 27-34.

(8) _________C. D. OWENS. M. H. HAYDAK, J. P. MILLS, and M. D. LEVIN. 1973.
SUPPLEMENTARY FEEDING OF HONEYBEE COLONIES IN ARIZONA. Am. Bee J. 113: 298-301.