In July 1931, while collecting beetles of the genus Donacia on rushes growing on the border of Lake of the Two-Mountains, near St. Placide, Que. I noticed a Hymenopterous insect alighting on one of these plants. It immediately walked down the stem, entering into the water and continued walking down, clinging to the stem of the plant, until it disappeared from view. Its movements under water were quite rapid. The water was about 24 to 30 inches deep.