Doctoral Thesis
Development, Colour Preference, and Survey Outcomes of Primary and Secondary Sheep Myiasis-Causing Fly Species in Australia: Implications for Mitigation Strategies
Murdoch University
Doctor of Philosophy (PhD), Murdoch University
2025
DOI:
https://doi.org/10.60867/00000082
Abstract
Sheep (Ovis aries. L) are highly vulnerable to a variety of ectoparasites, which adversely impact their well-being and overall productivity. Blow flies (Order: Diptera) play a significant role in sheep health, ranging from pathogen transmission to causing direct damage through myiasis. Myiasis, the infestation of live tissues by fly larvae, is a major cause of economic loss in livestock productivity worldwide. The present study investigated two critical sheep myiasis-causing fly species in Western Australia: Lucilia cuprina (Wiedemann) and Chrysomya rufifacies (Macquart). A third species was also studied, Lucilia sericata (Meigen), although involved in sheep myiasis globally, it is less of a problem in this respect in Australia. The research aimed to gather developmental data for L. sericata and Ch. rufifacies feeding on ovine skeletal muscle (both with and without fat) at two temperature regimes (24 ± 1°C and 30 ± 1°C), representing autumn and summer temperatures in Western Australia. Additionally, their pupation landmarks were comparatively analyzed based on the morphological changes of seven identified characters. The study revealed that the larval development duration was longest on ovine skeletal muscle tissues without fat, compared to those with fat, regardless of the fly species. Overall, L. sericata took more time to pass across four pupation landmarks at both temperatures than Ch. rufifacies. Further research on Ch. rufifacies pupal development in two soil types (loam and sand) under five moisture conditions (0%, 20%, 40%, 60%, and 80%) at 24 ± 1°C and 30 ± 1°C were conducted. This research showed a significant correlation between soil type and temperature concerning the time required to complete the pupal stages: however, moisture had no significant impact. Larvae exhibited varying survival rates across the two temperatures and five moisture levels in the two soil types, particularly under extremely low moisture conditions (0%) at 30 ± 1°C, where they failed to progress to the pupal stage. Previous studies have shown that flies can be attracted to the colour hues of discoloured wool on sheep, as well as to various colours of fly traps. A comparative analysis of the attraction of L. cuprina and Ch. rufifacies to different reflectance levels of green and yellow hues revealed that L. cuprina exhibited a stronger affinity for moderate yellow, whereas Ch. rufifacies showed a clear preference for moderate green. Additionally, the study generated two comprehensive reviews. The first review focused on existing knowledge about sheep myiasis, including fly-sheep interactions, types of myiasis, predisposing factors, clinical signs, the impact of climate change on the dispersal patterns of myiasis-causing flies, control strategies, and potential research directions. The second review summarized essential entomological and veterinary aspects necessary for conducting questionnaires and clinical observation surveys on sheep myiasis.
Details
- Title
- Development, Colour Preference, and Survey Outcomes of Primary and Secondary Sheep Myiasis-Causing Fly Species in Australia: Implications for Mitigation Strategies
- Authors/Creators
- Tharindu Bambaradeniya
- Contributors
- Ian Dadour (Supervisor) - Murdoch University, School of Medical, Molecular and Forensic SciencesPaola A. Magni OSI (Supervisor) - Murdoch University, School of Medical, Molecular and Forensic SciencesGarth Maker (Supervisor) - Murdoch University, Centre for Computational and Systems Medicine
- Awarding Institution
- Murdoch University; Doctor of Philosophy (PhD)
- Publisher
- Murdoch University
- Identifiers
- 991005869303107891
- Murdoch Affiliation
- School of Medical, Molecular and Forensic Sciences
- Resource Type
- Doctoral Thesis
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