Optimal Cold Temperature for the Artificial Hibernation of Bombus ignitus Queen Bumblebees

Abstract

Bumblebees are widely used to pollinate various greenhouse crops. Among the different bumblebee species, Bombus ignitus is indigenous to Korea, China, Japan and Russia. B. ignitus undergoes one generation per year, and artificial hibernation is essential for year-round rearing of the bumblebee. Keeping the queens under low-temperature conditions for several months is an effective method for terminating their diapause and promoting colony development. In the present study, we investigated how cold temperature affects the artificial hibernation of B. ignitus queens. Under chilling temperatures of -2.5°C, 0°C, 2.5°C and 5°C with constant humidity >80%, the queens stored at 2.5°C exhibited the highest survival rates, which were 74.0% at one month, 67.0% at two months, 60.0% at three months, 46.0% at 4 months, 33.0% at 5 months and 24.0% at 6 months. Lower survival rates were observed at 0°C, 5°C, 7.5°C and 12.5°C. At 2.5°C the colony developmental characteristics after diapause were 1.2-to 1.5-fold greater than those when queens were stored at 5°C. Thus, 2.5°C and 70% R.H.were the most favorable chilling temperature and humidity conditions for terminating the diapause of B. ignitus queens. Introduction AbstractInt.

A Combination Method of CO2-Narcosis and Cold Treatment for Breaking Diapause of Bombus ignitus and Bombus terrestris Bumblebee Queens

“…Therefore, the necessary cold period for B. ignitus queens was determined to be at least 2 mo. Yoon et al (2013) reported that a cold period of at least 2 mo applied 12 d after emergence was found to be the most favorable condition for diapause break in B. ignitus queens.…”

Immune Modulation of B. terrestris Worker (a Type of Bumblebee), Extract on CFA-induced Paw Edema in Rats

“…The bumblebees B. terrestris and B. hypocrita sapporoensis belong to Hymenoptera, family Apidae, Subfamily Apinae, and are adapted as bumblebees for the pollination of natural vegetation and agricultural plants (9) . Recently, B. terrestris workers have been abundant from the summer through the winter season because of mass artificial bumblebee production.…”

First field-based estimates of bumblebee diapause survival rates showcase high survivorship in the wild

“…Bumblebees are some of the most important native pollinators of crops in the United States (Kleijn et al 2015 ), and recently there has been great interest in understanding their biology throughout the life cycle (Liczner and Colla 2019 ; Williams et al 2019a ). Multiple studies (> 10) have monitored diapausing bumblebees in the lab, relating survival rates to environmental factors like temperature or relative humidity (Gretenkord and Drescher 1997 ; Yoon et al 2013 ; Lindsay 2020 ) or to intrinsic physiological factors like body mass (Woodard et al 2019 ; Treanore and Amsalem 2020 ). Many of the studies that target this lifecycle stage are focused on improving methods of husbandry or commercial rearing (Gretenkord and Drescher 1997 ; Beekman et al 1998 ; Yoon et al 2013 ; Lindsay 2020 ).…”

“…Multiple studies (> 10) have monitored diapausing bumblebees in the lab, relating survival rates to environmental factors like temperature or relative humidity (Gretenkord and Drescher 1997 ; Yoon et al 2013 ; Lindsay 2020 ) or to intrinsic physiological factors like body mass (Woodard et al 2019 ; Treanore and Amsalem 2020 ). Many of the studies that target this lifecycle stage are focused on improving methods of husbandry or commercial rearing (Gretenkord and Drescher 1997 ; Beekman et al 1998 ; Yoon et al 2013 ; Lindsay 2020 ). Conditions experienced by queens in the lab are not always ecologically realistic (e.g., Beekman et al 1998 ).…”