Wings- by Sarah Gabric

Wings

 

Honey bees have two pair of wings, carpeted in tiny spines, anchored in their upper thorax. When at rest, the hind wing lays under the fore. When in use, the upper edge of the hind wing locks into the hind edge of the fore wing via microscopic hooks, called humuli. The wings are relatively rigid as their surface (made of chitin like the cuticle) is enclosed by veins, cross veins and margins through which hemolymph (bee blood) flows.

 

In flight, honey bees’ wings move up-and-down and forward-and-backward in a figure 8 pattern. Powered by large indirect flight muscles which virtually fill the cavity of the thorax, a honey bee can move her wings 300 times per second. For comparison’s sake, dragonfly’s wings beat about 30 times and hummingbirds’ 70 times per second.

 Honey bees also use their indirect flight muscles to generate heat via metabolic friction by moving them isometrically, aka shivering. When a bee needs to produce heat and moving her wings would be untenable, such as when clustered, she can uncouple her wings from these muscles so that this activity does not result in wing motion. In addition to the large indirect muscles, there are several smaller muscles responsible for more subtle wing adjustments that allow honey bees to pilot themselves with precision and efficiency. All the flight muscles are supplied by abundant trachea, as they require high levels of oxygen to fuel the metabolic demands of flying.

 

Finally, in addition to wings being essential components of flight, they are also useful fans.  Honey bees’ use their wings to create and direct ventilation, which can be a critical for the colony when summer heat indexes soar, and internal hive temperatures can become deadly. During these times, honey bees distribute water droplets throughout the hive and fan them, creating in essence, mini swamp-coolers. Bees’ also use their wings to disseminate pheromones—you may have seen worker bees singly or lined up, often at the hive entrance, holding the ‘down-dog’ yoga pose (head down, abdomen raised).  They are exposing their Nasonov gland and whisking air over it to disperse this volatile pheromone.