Hibernate/ hibernation: hibernation is a winter survival strategy characteristic of some mammals in which an animal's metabolic rate slows down and a state of deep sleep is attained. Whilst hibernating, animals survive on stored reserves of fat that they have accumulated in summer. In insects, the correct term for hibernation is 'diapause', a temporary pause in development and growth. Any stage of the lifecycle (eggs, larvae, pupae or adults) may enter diapause, which is typically associated with winter.
Larvae: stage in an animal's lifecycle after it hatches from the egg. Larvae are typically very different in appearance to adults; they are able to feed and move around but usually are unable to reproduce.
Nearctic: the region including north America south to Mexico.
Palaearctic region: the region that includes Europe, the part of Asia to the north of the Himalayan-Tibetan barrier, North Africa and most of Arabia.
Pupae: stage in an insect's development when huge changes occur, which reorganise the larval form into the adult form. In butterflies the pupa is also called a chrysalis.
Pupal stage: stage in an insect's development, when huge changes occur that reorganise the larval form into the adult form. In butterflies the pupa is also called a chrysalis.
Prys-Jones, O.E., Olafsson, E. & Kristjansson, K. (1981) The Icelandic bumble bee fauna (Bombus Latr., Apidae) and its distributional ecology. J. Apicultural Research20 (3): 189-197; and see: http://www.nhm.ac.uk/entomology/bombus/bo.html#lucorum
Free, J.B & Butler, C. G (1959) The New Naturalist: Bumblebees. Collins, London.