A REEXAMINATION OF THE MORPHOLOGY OF THE HONEY BEE (APIS MELLIFERA L.)

Specimen preparation techniques developed for polarized light microscopy and the recognition of resilin led to this reexamination of the functional anatomy of the honey bee. The result is three new techniques that give an unequalled view of the form and function of the (1) cuticle and chitin fiber orientation, (2) muscular and exoskeletal anatomy and (3) muscular, exoskeletal and resilin anatomy. Two additional improved techniques are developed for the histological sectioning of resilin and the fluorescence of resilin.; The exocuticle and resilin as well as the endocuticle in the honey bee are deposited on a circadian rhythm. Resilin is in the mouthparts, thorax (mesosoma), legs and abdomen (gaster). Functional interpretations of the mouthparts are different from those of previous authors due to large amounts of resilin in the maxillae, hypopharynx and labium. Because of the resilin, there is a unique mandibular locking mechanism.; In the honey bee mesosoma, the ability to hover is due to a separation of the power production mechanism and the wing control mechanism, both of which have resilin. Observation with a strobe showed that a flying bee is composed of functional units. The power production mechanism consists of two of these functional units (the pronotum, mesonotum, mesoscutellum, metanotum and the mesothoracic and metathoracic pleural and sternal areas and propodeum) plus the fibrillar musculature and a large piece of resilin between the pronotal lobe (on the first functional unit) and the mesepisternum (on the second functional unit). These functional units vibrate up and down against one another and the elasticity of resilin. This action flaps the wings and also autoventilates the tracheal system. The wing control mechanism consists of the epipleural sclerites and associated musculature and several locations of resilin and the union of the meso- and metawings (which makes them function as single aerodynamic units). The several locations of resilin collectively have three functions. First, they act to withdraw the wings and overlap them over the abdomen. Second, they mediate the high frequency oscillations of the fibrillar musculature and the slow tonic tension of the wing control musculature. In this way, resilin is involved in all aspects of pronation vs supination, and the generation of lift vs thrust. Third, these collective locations of resilin in the wing control mechanism plus the resilin in the power production mechanism store and release energy in the top and bottom of the wing stroke. The honey bee is unique in this regard. The insect pterothorax has been defined as a harmonic oscillator or elastic system composed of the elasticity of the cuticle and the musculature and the resilin. A conceptually better way to view the role of resilin in the pterothorax of a flying insect is that it provides a bounce or an elastic collision at the top and bottom of the wing stroke. This research shows that the insect pterothorax is an elastic system dependent on cuticular and muscular elasticity plus the near perfect elastic collisions of resilin. Resilin in all of the trochanteral-femoral joints has a support function. Resilin in the proctiger extends it after defecation and resilin in the sting has a sensory function.; These techniques will find considerable use as tools in teaching and research. More importantly, resilin is clearly a normal part of the anatomy that offers several natural selective advantages. With the de novo evolution of resilin in specific sites, the form and function of the surrounding exoskeletal structure often changes. The reason for some of those changes have escaped systematic attention. Because we can now find resilin and assess its functional roles, there is considerable potential for future research.