The mandibular gland secretions and ovarial development of worker honeybees (Apis Mellifera) in the Eastern Cape Province of South Africa
- Authors: Reece, Sacha Louise
- Date: 2001
- Subjects: Honeybee -- South Africa -- Eastern Cape , Honeybee -- Behavior , Honeybee -- Physiology
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5729 , http://hdl.handle.net/10962/d1005415 , Honeybee -- South Africa -- Eastern Cape , Honeybee -- Behavior , Honeybee -- Physiology
- Description: The Eastern Cape is an area in which Apis mellifera capensis, A. m. scutellata and their hybrid are known to naturally occur. I investigated the mandibular gland profiles and ovarial development of queenright workers from 4 localities. Their queens were then removed to determine how these aspects changed upon queen loss. In addition, drifted bees were analysed in the same way to determine how these factors changed once they had gained entry to a foreign hive. The queenright bees, form all 4 localities were found to have 9HDA as the most abundant of the 5 fatty acids measured and all localities had small percentages of 9ODA in their mandibular gland secretions. This resulted in relatively high queenright 9ODA:10HDA and 9HDA:10HDAA ratios. Despite this the percentage of bees with undeveloped ovaries was consistent with their queenright status. The mean values of these 2 ratios were significantly higher in the bees from East London and Cradock than those from Port Elizabeth. Steynsburg's bees were intermediate in this regard. Upon queen loss, the bees from all 4 localities had an increase in the percentage of 9ODA but the other compound changes in varying ways. East London's bees were the only ones not to become significantly more queen-like after queen loss. After 14 days without a queen, the mean values of these 2 ratios were much higher in the bees from Port Elizabeth than those from the other localities. Certain individuals from Port Elizabeth had values of these ratios that exceeded those found in A. m. capensis queens. Port Elizabeth was the only locality to display any surrogate queens and exhibited the highest increase in the number of bees with partially or fully developed ovaries. While certain individuals from the other localities had values of these ratios that exceeded these values reported in A. m. scutellata queens, Steynsburg's bees were the only ones that did increase in in terms of the number of bees with developed ovaries subsequent. The bees from Steynsburg were shown to suppress the mandibular gland and ovarial development of drifters from Port Elizabeth while bees from East London did not.
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- Date Issued: 2001
Wax secretion in the Cape honeybee (Apis mellifera capensis esch.) in relation to juvenile hormone and age polyethism
- Authors: Muller, Nikite Wilhelmine Josephine
- Date: 1993
- Subjects: Honeybee -- Behavior , Honeycombs
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5797 , http://hdl.handle.net/10962/d1005485
- Description: 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.
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- Date Issued: 1993