The honey bee is a wonderful creature. Its behavior, physiology, and ecology are marvels to behold. The range of behaviors expressed by honey bees is diverse and sophisticated. Its internal workings keep the bee alive and healthy, ultimately producing an ecology that is profound, perhaps the most impressive of all the social insects. All of these wonders are made possible by the bee’s physical structure. Honey bees have an external anatomy that perfectly complements its function. It is this external anatomy to which I want to introduce you in this article, with the key words printed in bold font.
Honey bees are insects and there are certain physical characteristics that all insects share. Most notably, insects have three body regions and six legs (Figure 1). The body regions are called the head, thorax, and abdomen. Each body regions has its own important role to play in the overall function of the honey bee. Correspondingly, the external structure of each body region is developed to support the given region’s function.
As for other insects, a honey bee’s body is covered in a thick layer of cuticle that entomologists call exoskeleton, or external skeleton. The exoskeleton is made of a few different layers itself. However, it is sufficient to say that it forms the hard structure that protects the bee’s vital internal organs. It also serves as a point of attachment of muscle and other tissues of the body. The exoskeleton of the bee can be pigmented or lack pigmentation. Generally speaking though, the exoskeleton is what gives the bee its dark color since it usually is pigmented black or variations thereof, especially in the head and thoracic regions. That said, there is a special condition where bees produce brown pigmentation in areas that otherwise normally would be black. This produces a bee that is reddish-brown in color. This trait is called cordovan, hence the origination of the cordovan bee. Incidentally, the bee in Figure 5 is cordovan while the one in Figure 1 is not. You can see the clear difference in the coloration pattern of the two bees.
Bees’ bodies also are covered in hair. A bee’s hair differs from ours in one notable way. Our hairs are single shafts while a bee’s hair is branched. This is part of what distinguishes the bees from the wasps. The branched hairs help pollen stick to the bee’s body easier. Furthermore, these hairs build up an electrostatic charge as bees fly. This charge makes the pollen jump onto a bee’s body when she visits a flower. Clearly, these hairs are important to the survival of the bee colony.
The honey bee head is the center of sensory perception for the bee. Almost everything that a bee uses to sense the outside world is part of or connected to the head. The most notable external features of a bee’s head occur on the front or face of the bee (Figure 2). These include two large compound eyes, three small ocelli, two antennae, a tongue, and mandibles.
Bees have five eyes, two large compound eyes and three ocelli. The compound eyes are situated on either side of the bee’s head (Figure 3). The compound eyes are composed of thousands of little lenses or facets. Together, the facets help bees see color, movement, and patterns. The images from all of the lenses in a single compound eye are believed to be joined into a single image in the bee’s brain. The bees do not see images the way we see them. It is possible that they perceive images more like a mosaic, because they are less able to see definition and outlines. Interestingly enough, bees see further into the ultraviolet (UV) spectrum that do humans. Many flowers of bee-pollinated plants have petals containing patterns that only can be seen by organisms possessing the ability to see into the UV spectrum. Of final note, bees can detect polarized light, but do not see as far into the red spectrum as do humans. Red appears black to a bee.
The function of the three ocelli at the top of a bee’s head is less understood. These eyes are arranged in a triangular pattern and each contains only one lens. Ocelli, sometimes called simple eyes, aid in the detection of sunlight, or light intensity in general. Thus, the ocelli help bees navigate during flight.
Honey bees have two antennae that come out of the face between the compound eyes (Figures 2 and 4). The antennae are major sensory organs. They are covered in …