FARMER'S FRIEND

APICULTURIST U.S. DEPARTMENT OF AGRICULTURE UNIVERSITY OF ARIZONA

PHOTOGRAPHS BY HERB MCLAUGHLIN

Although there are numerous solitary bees na-tive to Arizona, honey bees were brought by the white man. The first honey bees, which the Indians called the "white man's flies," reached Arizona 234 years after their arrival in New England from Europe in 1638. Honey bees first reached San Francisco by boat from New York in 1853 and from the San Francisco-Sacramento area to San Diego in the early sixties. In 1872 General J. B. Allen moved two swarms of bees by wagon through the 500 miles of moun-tain and desert from San Diego, California, to Tucson. Thus did honey bees reach Arizona, and a new industry of ever growing importance was born. The first two swarms to issue from General Allen's colo-nies were sold to L. C. Hughes of Tucson who, during the next two years, increased them to fifteen colonies. Many swarms from these were distributed during the early 80's to residents throughout the southeastern part of Arizona. (For these historical notes we are indebted to the Honorable Sen-ator Carl Hayden.) According to the census, the industry had grown to 19,000 colonies at the turn of the century, and now, fifty years later, there are about 65,000 colonies in the state. Many people are surprised to find an abundance of nectar-yielding flora in the desert. The early honey crops undoubtedly THE BUSY HONEY BEE is one of the farmer's best friends in pollinating alfalfa and other crops. The services of bees in pollination has become an im-portant contribution to the state's resources. Intense studies has revealed that seed yield per acre of alfalfa increases greatly when colonies of bees are placed near the alfalfa fields. Furthermore, the spicy flavored alfalfa honey is considered a delicacy by many people. Nectar and pollen are food sources for honey bees.

Came largely from such native plants as mesquite, catsclaw and cacti, but cultivated plants were destined to grow in importance. Alfalfa was introduced into Arizona from California probably in the early 80's and its use spread rapidly in the agricultural valleys. Official records indicate that alfalfa contributed nearly half of the 1918 honey crop and cotton only three percent. The desert still supplies two-fifths, alfalfa onethird and cotton one-fifth of the annual Arizona honey crop. Thus, during the past thirty years, cotton has become an important honey source. Arizona honeys are distinctive. Many people prefer the rich flavors of mesquite and catclaw honey, while others enjoy the spicy flavored alfalfa honey.The development of bee culture has made a more important contribution to the state's resources than just the honey crop, for it provides pollination service for agricultural crops and ranges. The alfalfa seed, cantaloupe. watermelon and vegetable seed industries are largely dependent upon bees for pollination. Cotton production is probably aided, although this needs further clarification. The value of the production of these agricultural crops far outweighs the half million dollar annual returns from honey and beeswax.

Most part require an external agent to transfer pollen (the male element) to the stigma (the female part of the flower) before the ovule or egg can be fertilized and develop into seed and fruit. When plants such as alfalfa or melons are screened to prevent bee visits to their flowers-no seed or fruit is produced. If bees are introduced into such an experiment to serve as pollinating agents, the productivity of the same plants becomes so great it amazes the experimenter. The honey bee is a hairy creature and when it visits a flower to obtain nectar pollen grains become entangled in these hairs. Flowers are so constructed that the visiting bee will rub some of the pollen on the stigma. On a food collecting trip the bee visits only one species of plant and carries pollen from one plant to another, thus accomplishing the cross pollination necessary to maintain vigor in the offspring. The bee is interested in collecting food, but its visit to the flowers renders an indispensable service to plants.

The pollination of alfalfa has been intensively studied during and since the war because of an acute shortage of seed which could not be augmented by millions of dollars of subsidies or any other known means. An amazing discovery has recently been made which may revolutionize seed production methods. Scientists have, for many years, credited certain native bees, with a major role in the pollination of alfalfa. Recent studies, however, have shown that in the principal seed producing areas of the west. honey bees are doing most of the pollination work for which native bees had been given the credit. The importance of this discovery lies in the fact that the seed grower need no longer leave pollination to chance, because honey bee colonies can Flowering plants for the THE CONCENTRATION OF HONEY BEE colonies, when and where desired, means that the seed grower does not have to leave important pollination to chance. Flowering alfalfa plants require an external agent to accomplish crosspollination and for this role the honey bee is admirably adapted. An alfalfa field, poorly "tripped," has a solid bluish-purple appearance, while a "tripped" field rapidly acquires a brownish cast. A "tripped" field means greater seed yield.

Honey bees can be concentrated when and where they are desired. This cannot be done with native bees. By providing additional honey bee colonies, seed yields have been increased two fold and three fold over those obtained by the older method of leaving pollination to chance.

In newly cultivated areas of Arizona alfalfa seed yields of one thousand pounds or more per acre were obtained-but the cultivated acreage increased, and a greater demand arose for pollinators. The impact of agricultural development on native bees is severe, as their nesting sites in the soil are destroyed and insecticides kill the adults. On the other hand, honey bees are husbanded by man, and although they may be severely affected by insecticides, their numbers in the state have been maintained and increased more than five-fold during the past fifty years. This probably explains why native bees have declined in importance, while the honey bee industry has become an indispensable part of our agricultural economy.

Only a fifth of the 200,000 acres of alfalfa in Arizona is used for seed production. The seed acreage is definitely localized to Yuma County and in the Buckeye area of Maricopa County. These are the areas having the highest concentrations of apiaries, but this coincidence has been overlooked until recently. In other parts of Arizona, seed yields have been unaccountably too low for profitable production, but the recognition of the honey bee as a pollinator may help to extend to seed producing area.

The alfalfa flower is a classic example of a perfected floral structure designed to effectuate cross-pollination. It has an explosive pollinating mechanism which acts like a trap For bees. When the bee extends its proboscis into a flower, with its head pressed against the standard petal, a tripping mechanism is contacted which opens the keel and releases the sexual column. The tip of the sexual column bears the pollenyielding stamens and a stigma. When released, this column springs forth explosively striking forcefully the lower rear portion of the bee's head where it deposits a mass of pollen. The bee's head is pinched between the standard petal and sexual column, and when pulled free it still bears a pollen mass. Sometimes this "explosion" is so forceful that it actually can be heard and on rare occasions the bee is unable to extricate its head. Cross-pollination is accomplished by repeating this performance in the next flower visited, the stigma being embedded in the pollen mass from the previous flower until the bee frees its head. Until the flower is tripped, the sexual column is hidden within the keel, but, after tripping, it remains exposed to view, pressed firmly against the standard petal. Within a few hours the petal wraps around the sexual column and wilts, giving a field of rapidly tripped flowers a brownish cast. A field with few tripped flowers has a solid bluish-purple cast resembling a flower garden.

The pollen-gathering bee transfers pollen caught in its body hair to "baskets" on the outside of its hind legs. When a full load is collected, it is carried back to the hive where it is fed to young bees and eaten by nurse bees to be converted into royal jelly. Pollen supplies the colony with the protein, minerals and vitamins necessary in the bee's diet. while nectar supplies the carbohydrates. To obtain a load of pollen, the bee visits about 350 flowers.

Some idea of the size of the task of pollinating Arizona's alfalfa seed crop may be gained by an estimate of the number of flowers involved. About 400 million flowers are borne by an acre of alfalfa grown for seed and these will not produce seed pods unless tripped and cross-pollinated. At this rate the average 38,000 acres devoted to seed in Arizona would provide 15 trillion flowers to be visited during a four-weeks' flowering period by a field force of about 1.5 billion honey bees in the state. Of course, not all colonies are located in seed fields. It is not surprising that investigation indicates a deficient supply of pollinators, and that it is necessary to increase the number of colonies attending alfalfa fields from one per acre, which is profitable for honey production, to five or six to obtain seed yields of a thousand pounds or more per acre.

The construction of the alfalfa flower permits the collection of nectar without tripping. The bee inserts its proboscis between the overlapping wing and standard petals, avoiding the tripping mechanism and the forceful punch in the head that accompanies tripping. Individually, nectar gathering bees trip fewer flowers than pollen gatherers, the number depending on the condition of the plant. However, nectar gatherers usually outnumber pollen gatherers in the field and because of their greater numbers may contribute nearly as much tripping. Placing colonies in or adjacent to the alfalfa field may result in more tripping. Possibly the younger bees range less widely from the hive, or they trip more blossoms while "learning" to obtain nectar without tripping.

Of course, many factors enter into the setting of a good seed crop. Providing a heavy concentration of bees will not in itself insure a seed set. Proper attention must be given to the agronomic factors and the harmful insects must be controlled. Disregarding any of the essential factors may result in a seed crop failure. A problem which calls for unusual skill and ingenuity on the part of entomologists is how to control the harmful insects on alfalfa without also destroying the pollinators. The most harmful insects to seed production are the lygus bugs which feed on the developing buds and flowers, preventing adequate flowering and doing other damage. It is a tribute to entomological skill that methods have been worked out whereby these insects can be controlled with a minimum of destruction to the pollinators.

Arizona has some features which are unique in beekeeping. The intense summer sun makes it necessary to provide shade over apiaries. These shades are called ramadas and may be seen about the valleys. It is surprisingly cool in the shade of the ramada. This idea was probably borrowed from the Indians. In some locations supplying water for the bees becomes a problem. It has been found that a colony needs about a pint of water a day to maintain the bees in good condition. Where water is not available within a reasonable distance from the apiary, the beekeeper must haul it.

Back in 1872 it would have required unusual faculties on the part of General Allen to have visioned the value of the industry he was initiating. Even today it is difficult to grasp the full import of maintaining a healthy bee industry. Fortunate it is for the state that, during the three quarters of a century which have elapsed since bees were first brought to Arizona, the expansion of bee culture has kept pace with the rapid development of agriculture.

Expert studies and experiments prove importance of honey bee in seed production, resulting in great benefits to the industries.