Use this URL to cite or link to this record in EThOS: https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.284781
Title: Regulation of nest construction behaviour and nest development in Vespine wasps with special reference to Dolichovespula norwegica and D. sylvestris
Author: Cole, Mark Robert
ISNI:       0000 0001 3560 1082
Awarding Body: University of Glasgow
Current Institution: University of Glasgow
Date of Award: 1998
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Abstract:
The objective of this thesis was to examine various aspects of behavioural regulation of nest construction in Vespine wasps. This was achieved by examining nest structure principally in colonies of Dolichovespula sylvestris and Dolichovespula norwegica at various developmental stages. Some aspects of nest construction behaviour were also examined in Vespula vulgaris. The construction of the envelope requires a large investment in the time and resources of the colony. As the principal function of envelope is nest insulation, the amount constructed should reflect the requirement of the colony for thermoregulation. The thickness and number of layers of envelope constructed in nests of D. sylvestris and D. norwegica was found to increase with colony development, reaching a peak near the end of the lifecycle and when production of reproductives is at a maximum. Spradbery (1973) and Edwards (1980) claimed that small Vespine nests have proportionally thicker envelopes than large nests. The findings of this project did not agree with this claim and envelope thickness was found to increase linearly with nest diameter. This resulted from the allocation of a constant proportion of material to comb and envelope construction through colony development. The increase in envelope thickness is achieved by adding additional layers, while maintaining a constant gap between them. As the principal function of the envelope is insulation, temperature may act as a cue regulating its construction. Potter (1964) found evidence that the rate of foraging for pulp in V. vulgaris was affected by nest temperature. He did not, however, determine if this pulp was used in the construction of comb or envelope. A heated nest box and entrance trap were therefore developed to determine if environmental factors, such as temperature, affect the rate at which envelope is constructed. The nest box was successful in maintaining a colony of D. sylvestris transferred from the field. It was also capable of maintaining a range of temperatures selected by the experimenter of up to 35°C. The entrance trap was designed to allow foragers returning to the nest to be sampled and the type of forage carried to be determined. The entrance trap was based on a design by Harris (1989) for subterranean nests of V. vulgaris and V. germanica and was successfully adapted for separating and sampling foragers of D. sylvestris. Workers were found to exhibit a difference in behaviour when producing comb and envelope paper. Comb paper was found to be thinner and consisted of shorter fibres than that of envelope. In D. sylvestris and D. norwegica, comb paper was also found to be denser than that of envelope. D. sylvestris and D. norwegica were found to have very similar behaviour in fibre selection, pulp processing and paper manufacture. The Dolichovespula species were, however, found to exhibit several behavioural differences in paper manufacture to V. vulgaris. Comb and envelope fibres in V. vulgaris were found to be shorter and thicker than those of the Dolichovespula species. Comb and envelope paper was also found to be thicker in V. vulgaris than in D. sylvestris and D. norwegica. The use of short, thick fibres in V. vulgaris led to envelope with a lower tensile strength than that of D. sylvestris and D. norwegica. The ability of the colony to elevate its temperature was found to increase during development, reaching a peak at the start of the production of the reproductives. The colony showed its greatest ability to thermoregulate shortly before the maximum envelope thickness was reached in the nest. Several factors were examined which may limit the ability of the colony to elevate nest temperature. These included the number of workers, eggs, small larvae, large larvae and pupae. Differences between colonies in their ability to elevate nest temperature were only significantly explained by the number of old larvae present. Spradbery (1973) claimed that there is a higher density of comb supports on the upper combs than the lower combs. The findings of this thesis confirm this claim. In both D. sylvestris and D. norwegica, there was a higher density of supports on the upper comb in the nest than on any other comb. In constructing additional comb supports, workers appear to use a cue originating from a change in the size of the combs both directly and indirectly suspended. The cue for the construction of comb supports appeared to result from a change in the mass or size of comb suspended. The cue regulating the placement of the supports is, however, unknown. In D. sylvestris and D. norwegica, workers do not use the distance to neighbouring supports as a cue for initiating new supports. The results presented in this thesis indicate that workers use simple behavioural rules in the regulation of construction of comb, comb supports and envelope. The use of very simple behavioural rules may have penalties to the colony in terms of the adaptability of the nest structure. However they reduce the time spent by workers surveying the nest and processing information.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.284781  DOI: Not available
Keywords: Zoology
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