• International Journal of Industrial Entomology and Biomaterials
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• v.28 no.2
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• pp.58-65
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• 2014

Bumblebees are important pollinators of crops and wildflowers. Bumblebees generally produce one generation per year. One of the key stages for year-round rearing of bumblebees is breaking diapause. To evaluate the effects of a combination method of $CO_2$-narcosis and cold treatment to break the diapause of B. ignitus and B. terrestris queens, we determined whether this method affected their ability to establish a colony after the diapause break. The diapause treatment regimes that were utilized were $CO_2$ ($CO_2$-narcosis), CT-1M (cold treatment at $5^{\circ}C$ for 1 mo), CT-1M-$CO_2$ ($CO_2$-narcosis after cold treatment for 1 mo), CT-2M-$CO_2$ ($CO_2$-narcosis after cold treatment for 2 mo), CT-2M (cold treatment for 2 mo), CT-2.5M-$CO_2$ ($CO_2$-narcosis after cold treatment for 2.5 mo) and CT-2.5M (cold treatment at $5^{\circ}C$ for 2.5 mo). In view of the effects on the colony developmental characteristics of B. ignitus queens, the most favorable diapause treatment was CT-1M-$CO_2$. A combination method of $CO_2$-narcosis and cold temperature treatment yielded better results than that of single $CO_2$-narcosis or cold temperature treatment on the colony development of diapause-broken B. ignitus queens. In the case of B. terrestris queens, we concluded that a combination method of $CO_2$ and cold temperature treatment yielded better results than that of a single cold-temperature (up to 2 mo) treatment. In conclusion, the findings of the present study indicated that the combined application of $CO_2$ and cold temperature was a favorable method for the colony development of diapause-broken B. ignitus and B. terrestris queens compared with only $CO_2$-narcosis or cold temperature treatments. A combination method of $CO_2$ and cold treatment reduced the side effect of $CO_2$-narcosis and shortened the duration of cold treatment by at least 1 mo.

• International Journal of Industrial Entomology and Biomaterials
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• v.11 no.1
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• pp.21-25
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• 2005

As a means for year-round rearing of bumblebee, CO$_{2}$ -narcosis time favorable for colony development was identified in Bombus terrestris. CO$_{2}$ -narcosis time divided into five classes: 11 days of adult emergence (A-11), the day of adult emergence (A-0), late pupal stage (LP), middle pupal sta ge (MP), and early pupal stage (EP). In egg-laying characteristics, the oviposition rate of LP, A-11 and A-0 was over 76.0$\%$, but that of MP and EP was less than 61.1 $\%$. At the same time, the days needed to first oviposition shortened to 9.8 ­10.5 days in A-11, A-O and LP, comparing to 13.7 -16.1 days in MP and EP. The rate of colony foundation, progeny-queen produced and period of colony foundation of A-11 were the best results in among those at different CO$_{2}$-treatment time. The number of worker produced was 109.2 -110.5 in A-H, LP and A-H, comparing to 82.0 - 86.8 in MP and EP. Also, the number of progeny-queen produced of A-H, A-O and LP was 36.1, 41.0 and 71.3, respectively, which corresponded to 1.5 - 3.1 fold higher than MP and EP. Taken these together, CO$_{2}$-narcosis time favorable for colony development was determined to be 11 days of adult emergence. Also, the day of adult emergence and late pupal stage showed a positive effect on the oviposition and colony development in CO$_{2}$-narcosis time.

• Korean journal of applied entomology
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• v.47 no.1
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• pp.95-100
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• 2008

We compared colony development and survival rate after artificial hibernation between the bumblebees, Bombus terrestris, produced from domestic and foreign companies. The number of worker and queen produced from foundation colony of three domestic and one foreign companies was 232.4-270.8 and 62.0-181.8, respectively, but there was no statistical difference. In colony development of B. terrestris queens which were terminated diapause by $CO_2$ narcosis at different companies, oviposition rate, colony foundation and progeny-queen production of bumblebees produced from domestic companies were superior to those from foreign company. But foreign company in the number of worker and queen was superior to domestic companies. On the other hand, survival rate and colony development of B. terrestris queens, which were terminated diapause by artificial hibernation at three domestic and two foreign companies, were no significant differences. These results indicate that oviposition, colony foundation, progeny-queen production, and survival rate after artificial hibernation showed no differences between the bumblebees produced from domestic and foreign companies.