Honeybees Use Claw to Taste
Like many species in the animal kingdom, humans use their sense of smell and sight before they decide to taste something. These senses contribute to whether or not they personally will like what they are eating.
As for the honeybee, the species relies on color vision, memory, and sense of smell to find nectar. But before they eat their next meal, new research shows that the species will "taste" with the claws on their forelegs before extending their tongue to the nectar.
Insects taste through sensilla, hair-like structures on the body that contain receptor nerve cells, each of which is sensitive to a particular substance. In many insects, for example the honeybee, sensilla are found on the mouthparts, antenna and the tarsi — the end part of the legs. Honeybees weigh information from both front tarsi to decide whether to feed, finds the latest study led by Dr. Gabriela de Brito Sanchez, researcher, University of Toulouse, and Dr. Martin Giurfa, Director of the Research Centre on Animal Cognition, University of Toulouse, France.
Researchers conducted an experiment where sugary, bitter and salty solutions were applied to the tarsi of the honeybees' forelegs to test if this stimulated the bees to extend or retract their tongue — reflex actions that indicate whether or not they like the taste and are preparing to drink. Results revealed that honeybee tarsi are highly sensitive to sugar: even dilute sucrose solutions prompted the bees to extend their tongue. Measurements of nerve cell activity showed that the part of the honeybee tarsus most sensitive to sugary tastes is the double claw at its end. Also, the segments of the tarsus before the claws, known as the tarsomeres, were found to be highly sensitive to saline solutions.
Dr. Giurfa explains, "The high sensitivity to salts of the tarsomeres and to sugar of the tarsal claws is impressive given that each tarsus has fewer sensilla than the other sense organs. The claw's sense of taste allows workers to detect nectar immediately when they land on flowers. Also, bees hovering over water ponds can promptly detect the presence of salts in water through the tarsomeres of their hanging legs."
The study is published in the open-access journal, Frontiers in Behavioral Neuroscience.
Read more at EurekAlert.
Honeybee image via Shutterstock.