Some plants produce nectar that is poisonous to bees. It is difficult to understand how honey bees can produce honey from this toxic nectar. The effect on the bee is probably dose related at an individual as well as a colony level. The bee must consume a minimum amount of the toxin before it is affected. If the bee is visiting other non-toxic plants before returning to the colony, the toxin from the poisonous nectar may be diluted. Another factor …
What causes purple brood (honey bee larva that looks blue or purple, instead of white)?
The plant Cyrilla racemiflora, most often called southern leatherwood or summer titi, can cause larvae to turn purple when nectar or honey made from titi is feed to larvae. In 1932, Burnside discovered titi to be the cause of poisonings of half the bee colonies in Florida that year. He named the malady, “purple brood”, because affected larvae appeared blue or purple. Burnside reported that purple brood comes on suddenly and all the colonies in the affected area develop symptoms …
Are there plants that produce nectar that is poisonous to either honey bees or humans?
Plants can produce chemicals in sap, pollen, nectar or honeydew that are toxic to honey bees and humans. Some plants, such as the linden, are usually considered an excellent source of nectar, although under certain specific stress conditions, they have been shown to poison bees. These “specific stress conditions” seem to occur repeatedly in most cases of poisoning and they affect the dose of poison the bees receive. When environmental conditions, especially soil moisture, reduce other sources of nectar, the …