A model of flystrike pesticide resistance management on sheep: use of pesticide rotations
Pia Benedetti Vallenari A , Andrew Bailey A and Brian J. Horton![https://orcid.org/0000-0001-6522-4396](/media/client/orcid_16x16.png)
A Tasmanian Institute of Agriculture, University of Tasmania, Private Bag 1375, Launceston, Tas. 7250, Australia.
Animal Production Science 63(8) 802-815 https://doi.org/10.1071/AN22345
Submitted: 6 September 2022 Accepted: 31 January 2023 Published: 24 February 2023
© 2023 The Author(s) (or their employer(s)). Published by CSIRO Publishing. This is an open access article distributed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License (CC BY-NC-ND)
Abstract
Context: In some regions of Australia, the Australian sheep blowfly (Lucilia cuprina) is resistant to some of the pesticides used to control flystrike in sheep. Few pesticide groups are available, so it is important to delay or prevent any increase in resistance.
Aims: This study examined some of the assumptions in a previously developed model of pesticide resistance and tested the use of pesticide rotations as a means of limiting blowfly resistance to pesticides.
Methods: A model of sheep blowfly pesticide resistance was added to a previous model of sheep blowfly strike, to allow simulation of a range of pesticide management options for control of flystrike in sheep that might avoid increasing pesticide resistance.
Key results: The model requires some assumptions of settings that are uncertain, but the effects are not sensitive to a wide range of values for these settings. Resistance may not be obvious for some years after a new product is introduced, but once it has been detected, the frequency of resistance genes will increase rapidly if use of the same pesticide continues. The use of different pesticide groups each year is preferable to continuous use of the same product, but this risks losing efficacy of multiple products rather than one product at a time. However, rotations do provide a longer period of good protection from flystrike before all products used in the rotation fail. The number of years of successful protection against flystrike is extended if there is a fitness disadvantage for resistance to the products used.
Conclusions: The model may be useful for examining interactions between genes for resistance to different pesticides and the effect of non-chemical methods of control of flystrike, to extend the useful life of the current range of pesticides.
Implications: By the time resistance is detected on a farm, the level of resistance is high and will increase rapidly if the same pesticides continue to be used. Other non-pesticide methods such as breeding sheep for resistance to flystrike may be long-term solutions where resistance has reduced pesticide protection.
Keywords: flies, flystrike, genetics, model, pesticides, resistance, sheep, sheep blowfly.
References
Benedetti Vallenari P (2021) The development of a model for flystrike resistance management. Honours Thesis, University of Tasmania, Launceston, Tas., Australia.Campbell N, Horton B (2002) WoolRes: a model to assist producers to meet market requirements for low-residue wool. Wool Technology and Sheep Breeding 50, 632–637.
Colditz IG, Walkden-Brown SW, Daly BL, Crook BJ (2005) Some physiological responses associated with reduced wool growth during blowfly strike in Merino sheep. Australian Veterinary Journal 83, 695–699.
| Some physiological responses associated with reduced wool growth during blowfly strike in Merino sheep.Crossref | GoogleScholarGoogle Scholar |
Colvin AF, Reeve I, Kahn LP, Thompson LJ, Horton BJ, Walkden-Brown SW (2022) Australian surveys on incidence and control of blowfly strike in sheep between 2003 and 2019 reveal increased use of breeding for resistance, treatment with preventative chemicals and pain relief around mulesing. Veterinary Parasitology: Regional Studies and Reports 31, 100725
| Australian surveys on incidence and control of blowfly strike in sheep between 2003 and 2019 reveal increased use of breeding for resistance, treatment with preventative chemicals and pain relief around mulesing.Crossref | GoogleScholarGoogle Scholar |
Cook DF, Steiner EC, Watson I, Dadour IR (1995) Do Australian sheep blowflies, Lucilia cuprina (Diptera: Calliphoridae), breed in either goat or sheep carcasses in a semi-arid environment? The Rangeland Journal 17, 186–192.
| Do Australian sheep blowflies, Lucilia cuprina (Diptera: Calliphoridae), breed in either goat or sheep carcasses in a semi-arid environment?Crossref | GoogleScholarGoogle Scholar |
Grant EP, Wickham SL, Anderson F, Barnes AL, Fleming PA, Miller DW (2019) Remote identification of sheep with flystrike using behavioural observations. Animals 9, 368–384.
| Remote identification of sheep with flystrike using behavioural observations.Crossref | GoogleScholarGoogle Scholar |
Greeff JC, Karlsson LJE, Schlink AC (2014) Identifying indicator traits for breech strike in Merino sheep in a Mediterranean environment. Animal Production Science 54, 125–140.
| Identifying indicator traits for breech strike in Merino sheep in a Mediterranean environment.Crossref | GoogleScholarGoogle Scholar |
Hatcher S, Preston JWV (2015) Genetic parameters for breech cover, wrinkle and wool coverage scores and their implications for Merino sheep breeding programs and flock management. Small Ruminant Research 130, 36–46.
| Genetic parameters for breech cover, wrinkle and wool coverage scores and their implications for Merino sheep breeding programs and flock management.Crossref | GoogleScholarGoogle Scholar |
Heath ACG, Levot GW (2015) Parasiticide resistance in flies, lice and ticks in New Zealand and Australia: mechanisms, prevalence and prevention. New Zealand Veterinary Journal 63, 199–210.
| Parasiticide resistance in flies, lice and ticks in New Zealand and Australia: mechanisms, prevalence and prevention.Crossref | GoogleScholarGoogle Scholar |
Horton B, Hogan L (2010) FlyBoss: a web-based flystrike information and decision support system. Animal Production Science 50, 1069–1076.
| FlyBoss: a web-based flystrike information and decision support system.Crossref | GoogleScholarGoogle Scholar |
Horton BJ, Corkrey R, Doughty AK (2018) Sheep death and loss of production associated with flystrike in mature Merino and crossbred ewes. Animal Production Science 58, 1289–1296.
| Sheep death and loss of production associated with flystrike in mature Merino and crossbred ewes.Crossref | GoogleScholarGoogle Scholar |
Hughes PB, McKenzie JA (1987) Insecticide resistance in the Australian sheep blowfly, Lucilia cuprina: speculation, science and strategies. In ‘Combating resistance to xenobiotics’. (Eds MG Ford, DW Holloman, BPS Khambay, RM Sawicki) pp. 162–177. (Ellis Horwood: Chichester, UK)
James PJ (2006) Genetic alternatives to mulesing and tail docking in sheep: a review. Australian Journal of Experimental Agriculture 46, 1–18.
| Genetic alternatives to mulesing and tail docking in sheep: a review.Crossref | GoogleScholarGoogle Scholar |
Kotze AC, James PJ (2022) Control of sheep flystrike: what’s been tried in the past and where to from here. Australian Veterinary Journal 100, 1–19.
| Control of sheep flystrike: what’s been tried in the past and where to from here.Crossref | GoogleScholarGoogle Scholar |
Kotze AC, Bagnall NH, Ruffell AP, George SD, Rolls NM (2022) Resistance to dicyclanil and imidacloprid in the sheep blowfly, Lucilia cuprina, in Australia. Pest Management Science 78, 4195–4206.
| Resistance to dicyclanil and imidacloprid in the sheep blowfly, Lucilia cuprina, in Australia.Crossref | GoogleScholarGoogle Scholar |
Lang MD, Allen GR, Horton BJ (2006) Blowfly succession from possum (Trichosurus vulpecula) carrion in a sheep-farming zone. Medical and Veterinary Entomology 20, 445–452.
| Blowfly succession from possum (Trichosurus vulpecula) carrion in a sheep-farming zone.Crossref | GoogleScholarGoogle Scholar |
Levot G (2001) Implications of insecticide resistance for the control of flystrike and lice on sheep. In ‘Proceedings of the FLICS Conference, Launceston, Tasmania’. (Ed. S Champion) pp. 127–134. (Tasmanian Institute of Agricultural Research, University of Tasmania: Launceston, Tasmania)
Levot GW (2013) Response to laboratory selection with cyromazine and susceptibility to alternative insecticides in sheep blowfly larvae from the New South Wales Monaro. Australian Veterinary Journal 91, 61–64.
| Response to laboratory selection with cyromazine and susceptibility to alternative insecticides in sheep blowfly larvae from the New South Wales Monaro.Crossref | GoogleScholarGoogle Scholar |
Levot G, Sales N (2004) Insect growth regulator cross-resistance studies in field- and laboratory-selected strains of the Australian sheep blowfly, Lucilia cuprina (Wiedemann) (Diptera: Calliphoridae). Australian Journal of Entomology 43, 374–377.
| Insect growth regulator cross-resistance studies in field- and laboratory-selected strains of the Australian sheep blowfly, Lucilia cuprina (Wiedemann) (Diptera: Calliphoridae).Crossref | GoogleScholarGoogle Scholar |
Levot GW, Langfield BJ, Aiken DJ (2014) Survival advantage of cyromazine-resistant sheep blowfly larvae on dicyclanil- and cyromazine-treated Merinos. Australian Veterinary Journal 92, 421–426.
| Survival advantage of cyromazine-resistant sheep blowfly larvae on dicyclanil- and cyromazine-treated Merinos.Crossref | GoogleScholarGoogle Scholar |
Lucas P, Horton B (2013) Comparative costs, chemical treatments and flystrike rates in mulesed and unmulesed sheep flocks as predicted by a weather-driven model. Animal Production Science 53, 342–351.
| Comparative costs, chemical treatments and flystrike rates in mulesed and unmulesed sheep flocks as predicted by a weather-driven model.Crossref | GoogleScholarGoogle Scholar |
Miko I (2008) Genetic dominance: genotype–phenotype relationships. Nature Education 1, 140
Percival V, Horton B (2014) Use of a threshold of flystrike risk as a method for treatment intervention in the management of flystrike in sheep. Animal Production Science 54, 308–318.
| Use of a threshold of flystrike risk as a method for treatment intervention in the management of flystrike in sheep.Crossref | GoogleScholarGoogle Scholar |
Rose Vineer H (2020) What modeling parasites, transmission, and resistance can teach us. Veterinary Clinics of North America: Food Animal Practice 36, 145–158.
| What modeling parasites, transmission, and resistance can teach us.Crossref | GoogleScholarGoogle Scholar |
Sales N, Suann M, Koeford K (2020) Dicyclanil resistance in the Australian sheep blowfly, Lucilia cuprina, substantially reduces flystrike protection by dicyclanil and cyromazine based products. International Journal for Parasitology: Drugs and Drug Resistance 14, 118–125.
| Dicyclanil resistance in the Australian sheep blowfly, Lucilia cuprina, substantially reduces flystrike protection by dicyclanil and cyromazine based products.Crossref | GoogleScholarGoogle Scholar |
Shah RM, Shad SA, Abbas N (2015) Mechanism, stability and fitness cost of resistance to pyriproxyfen in the house fly, Musca domestica L. (Diptera: Muscidae). Pesticide Biochemistry and Physiology 119, 67–73.
| Mechanism, stability and fitness cost of resistance to pyriproxyfen in the house fly, Musca domestica L. (Diptera: Muscidae).Crossref | GoogleScholarGoogle Scholar |
Shah RM, Shad SA, Abbas N (2017) Methoxyfenozide resistance of the housefly, Musca domestica L. (Diptera: Muscidae): cross-resistance patterns, stability and associated fitness costs. Pest Management Science 73, 254–261.
| Methoxyfenozide resistance of the housefly, Musca domestica L. (Diptera: Muscidae): cross-resistance patterns, stability and associated fitness costs.Crossref | GoogleScholarGoogle Scholar |
Shephard R, Webb Ware J, Blomfield B, Niethe G (2022) Priority list of endemic diseases for the red meat industry – 2022 update. Meat & Livestock Australia, North Sydney, NSW, Australia.
Tang JD, Caprio MA, Sheppard DC, Gaydon DM (2002) Genetics and fitness costs of cyromazine resistance in the house fly (Diptera: Muscidae). Journal of Economic Entomology 95, 1251–1260.
| Genetics and fitness costs of cyromazine resistance in the house fly (Diptera: Muscidae).Crossref | GoogleScholarGoogle Scholar |
Tellam RL, Bowles VM (1997) Control of blowfly strike in sheep: current strategies and future prospects. International Journal for Parasitology 27, 261–273.
| Control of blowfly strike in sheep: current strategies and future prospects.Crossref | GoogleScholarGoogle Scholar |
Wardhaugh KG, Morton R, Bedo D, Horton BJ, Mahon RJ (2007) Estimating the incidence of fly myiases in Australian sheep flocks: development of a weather-driven regression model. Medical and Veterinary Entomology 21, 153–167.
| Estimating the incidence of fly myiases in Australian sheep flocks: development of a weather-driven regression model.Crossref | GoogleScholarGoogle Scholar |
Yen YL, Batterham P, Gelder B, McKenzie JA (1996) Predicting resistance and managing susceptibility to cyromazine in the Australian sheep blowfly Lucilia cuprina. Australian Journal of Experimental Agriculture 36, 413–420.
| Predicting resistance and managing susceptibility to cyromazine in the Australian sheep blowfly Lucilia cuprina.Crossref | GoogleScholarGoogle Scholar |