Date of Award
Arrestment, Behaviour, Blow flies, Locomotion, Tasting, Volatile organic compounds
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Behavioural plasticity is a concept that describes a change in an organism’s behaviour due to their exposure to stimuli that differ from their usual environment. For instance, females of many insect species alter their behavioural responses when exposed to differing substances that they utilize for feeding, oviposition, and/or mating. Behaviours such as the frequency of walking, tasting, grooming exhibited by flies can be associated with the detection and acceptance of a suitable medium. For this thesis, the arrestment and behavioural response of gravid adult females of three species of blow flies (Diptera: Calliphoridae), Lucilia sericata Meigen, Phormia regina Meigen, and Calliphora vicina Robineau-Desvoidy, were tested against six different profiles containing mixtures of three volatile organic compounds (including dimethyl disulfide, indole, phenylacetic acid, and isobutylamine). Each of these organic compounds have been previously found to be attractive to both larval and adult blow flies. Each profile mixture of VOCs corresponds to a diet lacking in one essential amino acid (either phenylalanine, tryptophan, valine, or methionine), each of which are critical to the growth and development of immature flies.
The results of this study indicate that on their own, these volatile cues result in increased arrestment behaviour, but not oviposition. Although demonstrating arrestment, L. sericata displayed no preference between the VOC profiles. In contrast, greater arrestment of P. regina occurred when the VOC profile lacked isobutylamine. Differing from the other two species, C. vicina exhibited a mixed arrestment response whereby no single VOC elicited a consistent response such that a particular cue was always sought or avoided. In terms of the pattern of behavioral switches between arrestment, locomotion, and tasting, overall, across species and VOC profiles, greater arrestment occurred, however, within a few species and within VOC profile differences were present. This was particularly true in C. vicina, where only two VOC profile combinations of phenylacetic acid versus indole and isobutylamine versus indole demonstrated greater arrestment than locomotion. Interestingly, this is the opposite for P. regina and L. sericata, that demonstrated no difference between locomotion and arrestment in the VOC profile combinations of isobutylamine versus indole. This behavioural plasticity demonstrates how different species of fly respond and forage differently despite having the same physiological needs.
Owen, Vanessa Elizabeth, "Mother Knows Best: Mechanistic Aspects of Foraging Preference and Differential Arrestment of Gravid Females: A Case Study on Blow Flies (Diptera: Calliphoridae)" (2022). Electronic Theses and Dissertations. 9119.