Wax secretion in the Cape honeybee (Apis mellifera capensis esch.) in relation to juvenile hormone and age polyethism

Muller, W.J. (1993) Wax secretion in the Cape honeybee (Apis mellifera capensis esch.) in relation to juvenile hormone and age polyethism. PhD thesis, Rhodes University.

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Abstract

Wax secretion in worker honeybees is significantly related to the age of the worker and, while the secretion pattern remains the same, the absolute amount of wax secreted varies seasonally. Comb building festoons, previously thought to be the site of wax secretion, contain only a fraction of the newly-secreted wax in the nest. Festooning behaviour was also found to be seasonal. The amount of wax secreted by workers was significantly affected by hive. Although age-related changes in behaviour and physiology of worker honeybees appears to be modulated by juvenile hormone (JH), wax secretion is not dependent on JH. Manipulating JH III titres by injecting the hormone and manipulating the only source of the hormone (the corpora allata: CA) did not affect wax secretion. Increasing haemolymph JH titre shortly after ec1osion did not affect the amount of wax produced by workers aged 3 to 21 days, nor could a critical period be found during which elevated hormone titres would affect the rate of wax secretion. Allatectomy of newly eclosed workers did not affect wax production. Removing the putative neural feedback inhibition on the CA did not result in a change in wax production. Implanting CA from older workers into younger workers had no significant effect. Methoprene, a widely-used JH analog, caused reduced wax secretion in workers. It is suggested that methoprene poisons worker honeybees. The results obtained are consistent with an alternative model for wax secretion proposed by Butler (1954). The methodological problems found in this work are present in many other studies. When viewed in this light, the role of JH in polyethism appears dubious and there are alternative models of polyethism that do not have these shortcomings.

Item Type:Thesis (PhD)
Uncontrolled Keywords:Wax, Secretion, Honeybees, Apis mellifera capensis esch., Worker, Age, Festoons, Comb building, Hive, Juvenile hormone, Physiology, Titres, Corpora allata, Methoprene, Poison, Polyethism
Subjects:Q Science > QL Zoology > Invertebrates > Insects
Divisions:Faculty > Faculty of Science > Zoology & Entomology
Supervisors:Hepburn, Randall
ID Code:4122
Deposited By: Philip Clarke
Deposited On:23 Nov 2012 09:47
Last Modified:23 Nov 2012 09:47
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