Does consuming irradiated royal jelly affect Apis mellifera larvae development and survival to adulthood in vitro?

Abstract

The purpose of this study was to determine if Apis mellifera could be reared in vitro on a diet containing royal jelly (RJ) irradiated at 25 kGy. Twelve-hour-old larvae were collected from fourteen colonies and fed a diet containing unirradiated RJ (refrigerated until use), irradiated RJ, or an irradiation control (RJ stored next to the irradiator for the time it takes to irradiate RJ). Statistically fewer larvae survived to adulthood when fed a diet containing irradiated RJ (70.6%) than when fed a diet containing unirradiated RJ (82.9%) or the irradiation control RJ (78.4%; F2,39 = 4.34; p < 0.001). Nevertheless, larval survival at day 8 and eclosion exceeded the U.S. Environmental Protection Agency’s requirements for controls in tier one toxicological studies. Feeding on irradiated RJ did not affect bee developmental time or weight at emergence. The data demonstrate that A. mellifera workers can be reared on a diet that includes irradiated RJ, but that additional diet refinements may be necessary to improve the survival of these individuals to levels experienced by larvae feeding on a diet containing unirradiated RJ.

Keywords:

• Apis mellifera
• royal jelly
• in vitro rearing
• irradiated diet
• toxicology

Acknowledgements

We would like to thank Susan Stanford (University of Florida) for access to the UF irradiator and help with irradiating the royal jelly, Chris Oster for assistance with material/supply purchases and meeting permit requirements, Brett Labella for in vitro rearing assistance, Brian Chiang for in vitro rearing assistance, Steven Keith for caging queens, and Dr. Dan Hahn for radiation support.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by funding provided by the Clay County Beekeepers Association (Clay County, Florida) and the USDA-APHIS via a cooperative agreement (AP22PPQS&T00C189) with the University of Florida.