Individual study: Treatment with carbon dioxide induces egg-laying in captive buff-tailed bumblebee queens Bombus terrestris; a laboratory study in Würzburg, Bayern, Germany
Röseler P.F. (1985) A technique for year-round rearing of Bombus terrestris (Apidae, Bombini) colonies in captivity. Apidologie, 16, 165-170
Bumblebees Bombus spp. are declining in Europe and America, and captive rearing followed by re-introduction is planned for one species in the UK. This laboratory study carried out in Würzburg, Bayern (Bavaria), southern Germany documents a technique to break hibernation and induce egg-laying in mated bumblebee queens, either caught from the wild or overwintered in captivity.
46 young mated buff-tailed bumblebee queens Bombus terrestris from laboratory-reared colonies were subjected to CO2 narcosis one day after mating. They were placed in a glass jar and treated with a CO2 stream until they became still. They were left in the closed jar for 30 minutes, then allowed to fly in a gauze cage. The process was repeated the following day.
After CO2 narcosis without hibernation, 33 of the 46 queens (72%) began egg-laying within one week. After CO2 narcosis and hibernation, 39 of the 48 queens (81%) began egg-laying within one week. All the queens treated this way eventually laid eggs, some after more than 10 days of confinement.
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