Use of natural sites and field hives by a long-tongued bumble beeBombus ruderatus

Abstract

Features of the sites of. 12 natural Bombus ruderatus colonies are reported; most were subterranean. This species (and B. terrestris) occupied 8-32% of 23-25 surface hives of bricks or pumice concrete, and 93% of 45 underground hives with earth floors and plastic roofs. High colony mortality, apparently caused by excessive condensation, occurred in plastic underground hives, but was remedied by replacing the plastic-roofed nesting cavities with partly buried pumice-concrete hives. The mean cocoon count In 16 completed B. ruderatus colonies was 418. A method for calculating a ‘productivity index’ based on mean sizes and numbers of worker or male and queen cocoons is described.