that honeybees should receive more credit as pollinators of red clover than has previously been accorded to them. “In 1925,” he writes, “I found that red-clover seed was produced in Ohio, West Virginia, and Kentucky. In some of the localities visited there were apparently few bumblebees, while in other places they were very abundant. In all cases the number of honeybees working on red clover far exceeded the number of bumblebees.”
Also in the Boise Valley, Idaho, according to E. F. Atwater, the production of red-clover seed is so profitable that the acreage of alfalfa has been greatly reduced. Honeybees are believed to be very important pollinators of the bloom. “When the alfalfa has all been cut,” he writes, “and honeybees are seen all over the red-clover blossoms, I shall believe until the contrary has been proved that much of the seed crop is due to their work.” On the other hand Waldron asserts that bumblebees are responsible for 95 per cent, of the red-clover seed produced in North Dakota. There are no reliable numerical data in existence showing how large a percentage of red clover flowers are pollinated by honeybees when gathering nectar alone. It is, however, well established that short-tongued bumblebees, the honeybee, and short-tongued solitary bees are not reliable pollinators of flowers having the nectar concealed in tubes longer than their tongues when they devote their attention wholly to gathering nectar and do not collect pollen. Bombus terrestris, one of the bumblebees introduced into New Zealand, has a short tongue, and has proved an unsatisfactory pollinator of red clover in that country. Thus the fact that thousands of honeybees have been observed gathering nectar does not prove that they were pollinating the flowers.
But honeybees in large numbers at times gather pollen from red-clover bloom, and then almost invariably they effect cross-pollination. In 1911 (Bull. No. 269, U. S. Dept. Agr.) honeybees collected large quantities of red-clover pollen, springing the keels, and pollinating the flowers. Westgate erected in a red-clover field a screened cage 12 feet square, in which he placed a small colony of bees. An average of 37 seeds per head was obtained. The bees collected pollen, as well as nectar, and it is certain that the crop of seed was in part, and it may have been wholly, due to pollination effected while the bees were seeking pollen. H. Mueller, as has been mentioned, saw hundreds of honeybees gathering red-clover pollen. Hopkins also noticed that they brought into the hives more or less pollen from red clover. A beekeeper in Illinois says that at times his bees have brought in red-clover pollen, but that he never could be certain that they gathered nectar. Pammel (Trans. St. Louis Acad. Sci., Vol. V., p. 248) saw honeybees gathering pollen at La Crosse, Wisconsin. In Iowa, in 1915, honeybees were observed collecting pollen from red-clover bloom on two or three days during the summer. Pammel is inclined to the opinion that honeybees do not gather nectar from red clover in Iowa, notwithstanding the opinion of many beekeepers in this state to the contrary. When honeybees gather red-clover pollen they are reliable pollinators of the flowers; but, as the anthers are enclosed in a keel or carina, this occurs apparently at irregular and rather infrequent intervals. (Fig. 49.)
The long-tongued bumblebees are admitted by everyone to be better adapted to the pollination of red clover than honeybees. A bumblebee can pollinate from 30 to 35 red clover flowers in a minute, and thus in two or three days a comparatively small number of them could pollinate millions of flowers. Taking into consideration all the localities throughout the world where red clover flourishes, the author is of the opinion that this species of clover is dependent chiefly on bumblebees for pollination. But in certain sections, where special conditions prevail, it is possible that honeybees may equal or exceed them in value. Basing his statement on many inquiries and observations, E. R. Root would give a larger amount of credit to the honeybee at least in the United States. “While the evidence at present,” he says, “is not conclusive, I believe that further inquiry and research will show beyond question that the honeybee in many localities has taken the place of the bumblebee as a pollinator of red clover. While the former is not so effective as the bumblebee,