A thesis submitted to the Faculty of Science, University of the
Witwatersrand, Johannesburg, in fulfilment of the requirements
for the degree of Doctor of Philosophy / In this dissertation the physical and chemical alterations induced by
mastication and manipulation of wax by the worker bee in honeycomb
construction, and the subsequent contribution afforded the structural integrity
of the nest, are elucidated.
In comb building, the freshly secreted wax scales are mandibulated together
with a frothy salivary emulsion, and added piece-meal to form honeycomb.
Textural modifications were revealed using X-ray crystallography. While virgin
scale wax is highly structured, with the crystallites aligned approximately
perpendicular to the planar surface, comb wax has a random crystallographic
arrangement. This reflects a disruption of the crystallite structure following the
mechanical insult of mastication. Chemical analyses included investigation of
both lipid and proteinaceous elements. Lipid composition was evaluated by
enzyme-catalyzed as well as thin-layer and gas-liquid chromatographic
methods. The results indicate a reduction in scale diacylglycerols with a
corresponding increase in comb saturated monoaeylglycerols. Such
modifications are highly suggestive of lipase activity within the salivary
addition. The proteins of comb and scale wax were analyzed
electrophoretically, under reduced conditions. Each wax possesses unique
polypeptide fractions, in addition to sharing common protein species, It is
speculated that those in common represent integral proteins, such as transport
molecules, while the disparities noted may be due to salivary enzymatic
degradation, or even glycosylation.
The effects of these textural and chemical alterations on the mechanical
behaviour of the waxes was assessed. Tensile tests were performed on a
variety of scale and comb wax preparations over the range of temperatures
likely to impinge on the honeybee nest. These investigations reveal the specific
structural contributions made by each of the physico-chemical alterations
described. Further, they demonstrate that while scales are ideal moulding
materials due to their high distensibility and low stiffness, the greater
resistance to deformation and lower potential for extension makes comb wax
a superior structural material. The mechanical advantage for including
propolis and cocoon silk within the comb structure was also investigated.
Tensile testing indicates that the resultant composite material is structurally
superior, largely due to the presence of silk reinforcement. / Andrew Chakane 2018
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:wits/oai:wiredspace.wits.ac.za:10539/26220 |
| Date | January 1990 |
| Creators | Kurstjens, Sef Paul. |
| Source Sets | South African National ETD Portal |
| Language | English |
| Detected Language | English |
| Type | Thesis |
| Format | application/pdf |
Page generated in 0.002 seconds