American Bee Journal
Dadant & Sons Inc
LD50 for worker honey bees of unknown ages exposed to topical applications was 1.5 micrograms/bee in 24 hours. LD50 for similar bees fed ronnel in sugar syrup was 3.0 micrograms/bee in 24 hours. Honey bees did not visit materials treated with ronnel in laboratory tests where bees had a choice between food with and without ronnel added.
Nye, W. P. 1975. Effect of Ronnel on the Honey Bee. Am. Bee J. 115(1):12-13.