Temperature and humidity favorable for colony development of the indoor-reared bumblebee, Bombus ignitus

Abstract

The optimum temperature and humidity for the indoor-rearing of Bombus ignitus were investigated. The experimental regimes of temperature and humidity were defined as 23°C, 27°C and 30°C under a constant humidity of 65% R.H., and 50%, 65% and 80% R.H. under a constant temperature of 27°C, respectively. Among the temperature regimes, 27°C-rearing showed the best results, i.e., the rates of colony initiation, colony foundation and progeny-queen production at 27°C were 83%, 63% and 46%, respectively, which corresponded to 2.2-5.5 times the respective values at other temperature regimes. The numbers of progeny produced at 27°C-rearing, 164±33 workers, 553±174 males and 33±48 queens were also higher, corresponding to 21.8 and 1.5 times those at 23°C and 30°C, respectively. In terms of humidity, 65% R.H. was favorable for big colony formation. Under the same humidity, the rates of colony initiation, colony foundation and progeny-queen production were 85%, 70% and 50%, respectively, and the number of progenies reached 180±30 workers, 578±179 males and 35±38 queens. Therefore, 27°C and 65% R.H. were determined to be the favorable environmental conditions for colony development of B. ignitus in indoor rearing.