The antennae of bees are amazing! They help to provide bees with the sense of smell, taste, and touch, and pick up sound vibrations.
Antennae perform a number of vital tasks, from assisting bees in locating flowers, to communication, finding a mate and more.
Bee antennae comprise 3 main parts, each made up of segments. The three parts are:
Male bees have longer antennae than females of the same species. Male antennae have 13 segments in total, whereas female antennae have 12 segments.
For example, worker honey bees are female, and therefore, each antenna has 12 segments, whereas drone antennae have 13 segments.
A bee's antennae pick up vital information from the environment in the form of sound, taste, scent and temperature via special sense organs.
The ability to pick up information from the environment enables bees to further make use of their antennae in a variety of ways. Which brings us to our next point:
There are many ways in which bees use antennae. Here are just three specific examples:
Antennae assist in foraging
Because the antennae are important for the sense of smell, then the use of both antennae enables bees to detect and locate the source of a scent to a flower2.
In honey bees it is known that the honey bee dance signals are picked up from one bee via the other, thanks to the Johnston's Organ located in the antennae4,5.
Finding a mate
Honey bee drones can detect queens via scent cues picked up by the antennae. Compared with worker bees, drones have larger antennae and about seven times as many sensilla6. Thus drones have 18,600 olfactory sensilla per antenna, each equipped with receptor neurons sensitive to the queen's sex pheromone7.
Bees have a special structure on their forelegs which they use to clean their antennae.
This antennae cleaner is called a 'strigilis', which is a comb-like structure inside a curved 'notch'. Incidentally, its name 'strigilis' may have its origins in the name used for a curved blade or scraper used by the ancient Greeks and Romans to scrape dirt and sweat from their bodies.
As far as can be ascertained, all bees have strigilis on their forelegs, and a study (Schönitzer 2009)8 examining 175 species of bee found there are slight differences between the structure of antennae cleaners among species.
Research in a study (Schönitzer 1986)9 of antenna grooming in more than 100 species of bees from 34 genera of the 7 major bee families found that most species are either:
The study also found that in several species, males and females differ with respect to their antenna cleaning behaviour, females tend to be more uniscraping.
Many bees have genticulate antennae. Genticulate antennae have an abrupt bend or elbow part of the way along the antennae between the scape and the pedicel. Bumble bees and honey bees have genticulate antennae, along with many other bees species, but not all. For example, some solitary species have filiform antennae.
1. Maria Gabriela de Brito Sanchez, Taste Perception in Honey Bees, Chemical Senses, Volume 36, Issue 8, October 2011, Pages 675–692, https://doi.org/10.1093/chemse/bjr040
2. Solitary Bees - by Ted Benton - p. 46. & 101.
3. Rands SA, Whitney HM. Floral temperature and optimal foraging: is heat a feasible floral reward for pollinators? PLoS One. 2008 Apr 23;3(4):e2007. doi: 10.1371/journal.pone.0002007. PMID: 18431488; PMCID: PMC2292243.
4. Tsujiuchi S, Sivan-Loukianova E, Eberl DF, Kitagawa Y, Kadowaki T. Dynamic range compression in the honey bee auditory system toward waggle dance sounds. PLoS One. 2007;2(2):e234. Published 2007 Feb 21. doi:10.1371/journal.pone.0000234
5. Ai H, Rybak J, Menzel R, Itoh T. Response characteristics of vibration-sensitive interneurons related to Johnston's organ in the honeybee, Apis mellifera. J Comp Neurol. 2009 Jul 10;515(2):145-60. doi: 10.1002/cne.22042. PMID: 19412925.
6. A honey bee odorant receptor for the queen substance 9-oxo-2-decenoic acid Kevin W. Wanner, Andrew S. Nichols, Kimberly K. O. Walden, Axel Brockmann, Charles W. Luetje, Hugh M. Robertson Proceedings of the National Academy of Sciences Sep 2007, 104 (36) 14383-14388; DOI: 10.1073/pnas.0705459104
7. Brockmann A, Brückner D. Structural differences in the drone olfactory system of two phylogenetically distant Apis species, A. florea and A. mellifera. Naturwissenschaften. 2001 Feb;88(2):78-81. doi: 10.1007/s001140000199. PMID: 11320892.
8. Schönitzer, B.K. (1986), Comparative morphology of the antenna cleaner in bees (Apoidea). Journal of Zoological Systematics and Evolutionary Research, 24: 35-51. https://doi.org/10.1111/j.1439-0469.1986.tb00614.x
9. SCHÖNITZER, K. (1986), Quantitative Aspects of Antenna Grooming in Bees (Apoidea: Hymenoptera). Ethology, 73: 29-42. https://doi.org/10.1111/j.1439-0310.1986.tb00997.x