No abstract

Two bumble bee observation hive designs are described. Both have a sloping floor to support peripheral brood clumps. One is temperature controlled, using insulated resistance wire as an internal heat source. The other is moulded from a concrete mixture consisting of horticultural Perlite, cement, and plaster of Paris. Techniques for the sanitation, feeding, and handling of laboratory colonies are described.

Observations of five free foraging colonies of Bombus (Megabombus) ruderatus (Fab.) are reported with respect to brood production and mortality. Emphasis is given to the nutrition of larvae and new adults, and larval ejection. Seasonal trends in the sex, caste, and size of adults are reported. Colony size was relatively large for a temperate Bombus species. Intraspecific variation in colony size was related to the timing of male production.

No abstract

The first-brood worker populations of 18 artificially fed colonies of Bombus perplexus were adjusted to two, four, or eight and allowed to treble with the emergence of the second brood. The timing of male production was independent of the number of workers present and independent of the time of colony initiation. Consequently the duration of the premale period was correlated with the earliness of colony initiation. The first queens emerged after a mean delay of 3.2 days after the first males, this delay being shorter if more workers were present. The rate of pollen consumption per unit larval area was lower with only two workers present than when there were four or eight, but no association was found between the time of initiation of queen production and high ratios of worker numbers to larval area.