Thaindian News

Washington, Feb 11 (IANS) Bees seem to be addicted to nectar with traces of nicotine and caffeine rather than plain honey, says a new study.
“This could be an evolutionary development intended, as in humans, to make the bee addicted,” states Ido Izhaki, one of the researchers who conducted the study at the University of Haifa (U-H) in Israel.

Flower nectar comprises sugars, which provide energy for the potential pollinators, but such nectar from some plant species also includes small quantities of toxic substances like caffeine and nicotine.

The present study examined whether these substances are intended to “entice” bees or whether they are by-products.

Nicotine is found naturally in floral nectar at a concentration of up to 2.5 milligrams (mg) per litre, primarily in various types of tobacco trees (Nicotiana glauca).

Caffeine is found at concentration levels of 11-17.5 mg per litre, mostly in citrus flowers. In the nectar of grapefruit flowers, however, caffeine is present in much higher concentrations, reaching 94.2 mg per litre.

In order to examine whether bees prefer nectar containing caffeine and nicotine, the researchers offered artificial nectar that comprised various natural sugar levels and various levels of caffeine and nicotine, alongside “clean” nectar that comprised sugar alone.

The caffeine and nicotine concentrations ranged from the natural levels in floral nectar up to much higher concentrations than found in nature, said an U-H release.

The results showed that bees clearly prefer nectar containing nicotine and caffeine over the “clean” nectar. The preferred nicotine concentration was one mg per litre, similar to that found in nature.