The Basics of a Bee’s Anatomy
Like all insects, bees’ bodies consist of three distinct parts: the head, abdomen and thorax. A bee has six legs with three on each side of the thorax. It also has a long tongue (proboscis) that functions as a straw and is used to essentially suck up water and nectar.
Located at the very end of its abdomen is the sting. This is used to sense if there is a danger to either the bee itself or the colony as a whole.
Bees also have two antennae that they use for smell and touch. On each side of a bee’s head, there are large compound eyes that consist of many tiny eyes clustered together.
A Bee’s Wings
The wings of a bee play a significant role in its scientific name. Bees are part of the Hymenoptera order. It’s a word stemming from the Greek language — when translated, it literally means membrane (hymen) wings (ptera).
Bee wings are made up of a fibrous substance called chitin. Chitin is the same material that makes up the body wall — wings are an extension of the bee exoskeleton.
If you were to give a bee a quick, cursory glance, you might think that it only has two wings. When a bee is at rest, the wings lay gently on top of each other. If you were to look closer, you would realize that they have a total of four.
Bees have two sets of wings on each side of the thorax. They possess a pair of forewings that are almost the same length as the abdomen and a smaller set of hindwings.
In flight, both pairs of wings join together to create one larger wing on each side. This is made possible by a row of hooks — called humuli. These humuli are located on the edge of the hindwings and lock into grooves on the trailing edge of the forewings. Once a bee has landed they release.
Aside from helping bees fly, wings also help bees to ventilate the hive, which in turn, lowers the moisture content in the honey.
Flight Muscles
The wings of a bee are powered by the longitudinal and vertical muscles located inside the thorax. Consuming almost the entire middle section, this pair of muscles is essential to allow bees to fly.
When the longitudinal muscles contract, the thorax raises its height and allows the wings to be lowered. The vertical muscles work oppositely. When they contract, the height of the thorax is shortened, and the wings are raised.
This muscle movement occurs multiple times with one nerve impulse, allowing bees to fly at an incredible speed. Here are a few bee flight facts:
- Bees fly at a speed of 7.5 and 6.5 meters per second respectively for unloaded and loaded bees
- The wingbeat frequency of a bee is approximately 125-130 beats per second
Effects of Temperature on Flight
If the wing muscle temperature falls below 96.8 degrees Fahrenheit. (36 degrees Celsius) they can’t function, hence, the bee cannot fly. As bees are cold-blooded, they have to find ways to elevate it themselves.
During flight, the temperature is maintained by the wing muscles — every contraction generates heat. It’s regulated to remain between the range of 96.8-111.2 degrees Fahrenheit (36-44 degrees Celsius).
When resting, a bee’s body temperature adjusts to that of its surroundings. The bee utilizes a shivering mechanism, to raise the flight muscle temperature high enough to take off.
You can observe this in a grounded bee as its abdomen pumps up to aid in the warming up of the flight muscles. This pumping rate can be measured and indicates the bee’s body temperature. It takes anywhere from a few seconds to fifteen minutes to reach the mark that is conducive to and necessary for flight.
Bees will typically not venture outside if the ambient temperature falls below 50 degrees Fahrenheit (10 degrees Celsius). If food supplies are short, however, a queen will leave the nest in even lower temperatures. In these severe conditions, bees vary their flying height to take advantage of any temperature differences in the air.
Summary
The mechanisms for hooking and warming up bees’ wings are incredibly complex, yet extremely important for understanding their anatomy. If you were to glance at a bee in flight, you would assume that a bee only has two wings.
Bees do, have four wings — a set of large forewings and smaller hindwings. When seamlessly latched together by humuli, they also function as two stronger wings.
