Nesting Habits of a Solitary Bee of the Genus Spinoliella of Ashmead

The nests of the bees of this genus are generally hard to find. The insects are so small, usually not more than a quarter inch long, that they are difficult to follow in their flight. I n fact, so far as I can tell, no information is available on their nesting habits. It was on a fine sunny day in the latter part of August, 1927, while visiting the Country Club a t Denver, Colorado, that my attention was called to some small mounds of dark soil resembling ant nests. These were located along the side of a tennis court. It was soon evident that they were the nests of some bees. They had picked three different areas in which to establish their dwellings. Each colony possessed some forty or fifty nests separated from one another by a distance of about six inches. Each day the courts had been moistened and rolled by the caretaker. And each day the busy owners had thrown up the small mounds of soil over their entrances. When I arrived, the colonies were bustling with work. Here was a bee opening the entrance to her nest. Up the tunnel she backed, pushing a load of earth. When almost to the top, she suddenly stopped and descended for another load. The earth in the entrance-way remained without falling. Presently she was up again with some more. This was also pushed out of the entrance a portion remaining in the passage-way as before. The little mound of soil above the nest was steadily increasing in size. Over here was a female just in from the fields. Her hind legs were heavy and quite conspicuous with their loads of green pollen. Back and forth she circled, undecided which of the nests was her own. Several times she alighted on the ground. After a minute, the problem solved, she hovered over her nest and entered. I n other