Comparative in vitro evaluation of contact activity of fluralaner, spinosad, phoxim, propoxur, permethrin and deltamethrin against the northern fowl mite

calendar icon 4 October 2018
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Northern fowl mites (Ornithonyssus sylviarum) are obligate hematophagous ectoparasites of both feral birds and poultry, particularly chicken layers and breeders. They complete their entire life-cycle on infested birds while feeding on blood. Infestations of O. sylviarum are difficult to control and resistance to some chemical classes of acaricides is a growing concern. The contact susceptibility of O. sylviarum to a new active ingredient, fluralaner, was evaluated, as well as other compounds representative of the main chemical classes commonly used to control poultry mite infestations in Europe and the USA.


Six acaricides (fluralaner, spinosad, phoxim, propoxur, permethrin, deltamethrin) were dissolved and serially diluted in butanol: olive oil (1:1) to obtain test solutions used for impregnation of filter paper packets. A carrier-only control was included. Thirty adult northern fowl mites, freshly collected from untreated host chickens, were inserted into each packet for continuous compound exposure. Mite mortality was assessed after incubation of the test packets for 48 hours at 75 percent relative humidity and a temperature of 22°C.


Adult mite LC50 /LC99 values were 2.95/8.09ppm for fluralaner, 1587/3123ppm for spinosad, 420/750ppm for phoxim and 86/181ppm for propoxur. Permethrin and deltamethrin LC values could not be calculated due to lack of mortality observed even at 1000 ppm.


Northern fowl mites were highly sensitive to fluralaner after contact exposure. They were moderately sensitive to phoxim and propoxur, and less sensitive to spinosad. Furthermore, the tested mite population appeared to be resistant to the pyrethroids, permethrin and deltamethrin, despite not being exposed to acaricides for at least 10 years.

by Bradley A. Mullens, Amy C. Murillo, Hartmut Zoller, Anja R. Heckeroth, Faris Jirjis and Annie Flochlay-Sigognault

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Two major ectoparasite species severely affect the poultry industry worldwide: the northern fowl mite, Ornithonyssus sylviarum, and the poultry red mite, Dermanyssus gallinae.1 2 Both mite species are obligate hematophagous parasites able to complete their life-cycles within about 1 week under optimal conditions.2 3 4 Mite populations can become dense very quickly in commercial poultry facilities reducing hen performance and profitability.5 6 They differ mainly in that all stages of O. sylviarum mites live on the host full time, occupying and laying eggs in the fluffy feathers mostly of the vent region (Fig. 1),1 while D. gallinae lives predominantly off-host, hidden in cracks and crevices, and comes out nocturnally to feed on the birds.2 Classical approaches to treat mite infestations mostly include the use of acaricidal sprays applied to the environment or to the host itself.6 However, a complicating factor for both mite species is that they can persist without hosts for weeks and perhaps months in the environment.7 8 Their very small size makes them a difficult target for spray treatments and subsequent disinfestation of poultry houses between flocks. In addition, these acaricidal sprays must penetrate the feather layer from under the birds (vent region) to treat O. sylviarum on host, which make it difficult to spray birds in enriched cage or cage-free systems.

Fig. 1 Northern fowl mites (Ornithonyssus sylviarum) on the vent region of an infested hen. A representative cluster of feeding mites indicated by an arrow

In North America, O. sylviarum is the most prevalent ectoparasite of commercial laying hen operations.1 Control efficiency is threatened by serious mite resistance to a shrinking arsenal of acaricidal compound classes,9 especially for the synthetic pyrethroids, but also against carbamates and organophosphates. In the USA synthetic on-host control chemicals for O. sylviarum 15 years ago included the carbamate carbaryl, the organophosphate mixture tetrachlorvinphos/dichlorvos, and permethrin. Currently only permethrin is widely allowed for use, tetrachlorvinphos or its mixture with dichlorvos are used in some states, and carbaryl is no longer allowed.10 Alternatives to traditional acaricides, such as botanical products or inert dusts, have been explored for both O. sylviarum and D. gallinae control, with inconsistent results; botanical products are notoriously variable, while silica dusts can be difficult to deploy effectively.2 10 11 Entomopathogenic fungi, especially Beauveria bassiana and Metarhizium anisopliae, have promise for control of D. gallinae and perhaps of O. sylviarum, although results have been mixed.12 13 14 It is critical that we explore other options, including new synthetic acaricides.2

Twenty-first century developments of new classes of acaricidal compounds like isoxazolines, have restored optimism that safe and effective pest control could be maintained for crop, premise protection, and animal health. Isoxazolines work by binding to invertebrate GABA and glutamate channels,15 but act at previously unrecognised sites. This mitigates cross-resistance to other chemotypes, and differing target sites between arthropods and mammals result in selective toxicity and mechanistically based safety.16 Isoxazolines, including fluralaner, afoxalaner and sarolaner, are under development and are of increasing importance in the control of external parasites in dogs and cats, including mites.17 18 19 20 The present study was conducted to determine if fluralaner possesses contact activity against O. sylviarum, and compare this activity with that of other acaricides commonly used against mite infestations of poultry.

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Northern fowl mites were highly susceptible to fluralaner by contact in this study. This mite resides primarily in the fluffy feathers of the vent region of chickens, where protonymphs and adults blood feed. This ectoparasite causes considerable economic damage to egg laying hens, caused by blood-feeding and the subsequent immune responses.6 Pesticide sprays are currently the primary method of controlling O. sylviarum. The pesticides must be sprayed from underneath the birds at high pressures to effectively treat the mites living in the vent feathers. As birds are moved into alternative cages with solid floors and other structures, or cage-free environments, this type of treatment will become difficult to execute. Fluralaner has a higher contact activity than other acaricides we tested for O. sylviarum. This activity, together with its expected systemic activity, as demonstrated for it and other isoxazolines against other mite species,16, 19, would make fluralaner a valuable addition to the poultry mite control palette.


1. Axtell RC, Arends JJ. Ecology and management of arthropod pests of poultry. Annu Rev Entomol. 1990;35:101–6.

2. Sparagano OAE, George DR, Harrington DWJ, Giangaspero A. Significance and control of the poultry red mite, Dermanyssus gallinae. Ann Rev Entomol. 2014;59:447–66.

3. Sikes RK, Chamberlain RW. Laboratory observations on three species of bird mites. J Parasitol. 1954;40:691–7.

4. McCulloch JB, Owen JP. Arrhenotoky and oedipal mating in the northern fowl mite (Ornithonyssus sylviarum) (Acari: Gamasida: Macronyssidae). Parasit Vectors. 2012;5:281.

5. Kilpinen O, Roepstorff A, Permin A, Norgaard-Nielsen G, Lawson LG, Simonsen HB. Influence of Dermanyssus gallinae and Ascaridia galli infections on behavior and health of laying hens (Gallus gallus domesticus). Br Poult Sci. 2005;46:26–34.

6. Mullens BA, Owen JP, Kuney DR, Szijj CE, Klingler KA. Temporal changes in distribution, prevalence and intensity of northern fowl mite (Ornithonyssus sylviarum) parasitism in commercial caged laying hens, with a comprehensive economic analysis of parasite impact. Vet Parasitol. 2009; 160:116–30.

7. Nordenfors H, Hoglund J, Uggla A. Effects of temperature and humidity on oviposition, molting, and longevity of Dermanyssus gallinae (Acari: Dermanyssidae). J Med Entomol. 1999;36:68–72.

8. Chen BL, Mullens BA. Temperature and humidity effects on off-host survival of the northern fowl mite (Acari: Macronyssidae) and the chicken body louse (Phthiraptera: Menoponidae). J Econ Entomol. 2008;101:637–46.

9. Mullens BA, Velten RK, Hinkle NC, Kuney DR, Szijj CE. Acaricide resistance in northern fowl mite (Ornithonyssus sylviarum) populations on caged layer operations in southern California. Poultry Sci. 2004;83:365–74.

10. Registered Pesticides Database. UCR, Riverside, CA. 2015. http:// Accessed 1 Mar 2017.

11. Martin CD, Mullens BA. Housing and dustbathing effects on northern fowl mites (Ornithonyssus sylviarum) and chicken body lice (Menacanthus stramineus) on hens. Med Vet Entomol. 2012;26:323–33.

12. Tavassoli M, Ownag A, Pourseyed SH, Mardani K. Laboratory evaluation of three strains of the entomopathogenic fungus Metarhizium anisopliae fntrolling Dermanyssus gallinae. Avian Pathol. 2008;37:259–63.

13. Mullens BA, Soto D, Martin CD, Callaham BL, Gerry AC. Northern fowl mite (Ornithonyssus sylviarum) control evaluations using liquid formulations of diatomaceous earth, kaolin, sulfur, azadirachtin and Beauveria bassiana on caged laying hens. J Appl Poult Res. 2012;21:111–6.

14. Immediato D, Figueredo LA, Iatta R, Camarda A, Nogueira de Luna RL, Giangaspero A, et al. Essential oils and Beauveria bassiana against Dermanyssus gallinae (Acari: Dermanyssidae): toward new natural acaricides. Vet Parasitol. 2016;229:159–65.

15. Gassel M, Wolf C, Noack S, Williams H, Ilg T. The novel isoxazoline ectoparasiticide fluralaner: selective inhibition of arthropod y-aminobutyric acid and L-glutamate-gated chloride channels and insecticide/acaricidal activity. Insect Biochem Mol Biol. 2014;45:111–24.

16. Casida J. Golden age of RyR and GABA R diamide and isoxazoline insecticides: common genesis, serendipity, surprises, selectivity and safety. Chem Res Toxicol. 2015;28:560–6.

17. Taenzler J, Liebenberg J, Roepke R, Frénais R, Heckeroth A. Efficacy of fluralaner administered either orally or topically for the treatment of naturally acquired Sarcoptes scabiei var. canis infestation in dogs. Parasit Vectors. 2016;9:392.

18. Wengenmayer C, Williams H, Zschiesche F, Moritz A, Langenstein J, Roepke RKA, Heckeroth AR. The speed of kill of fluralaner (Bravecto) against Ixodes ricinus ticks on dogs. Parasit Vectors. 2014;7:525.

19. Beugnet F, Liebenberg J, Halos L. Comparative efficacy of two oral treatments for dogs containing either afoxolaner or fluralaner against Rhipicephalus sanguineus sensu lato and Dermancentor reticulatus. Vet Parasitol. 2015;209:142–5.

20. Becskei C, De Bock F, Illambas J, Cherni JA, Fourie JJ, Lane M, Mahabir SP, Six RH. Efficacy and safety of a novel oral isoxazoline, sarolaner (Simparica™), for the treatment of sarcoptic mange in dogs. Vet Parasitol. 2016;222:56–61.

21. Stone BF, Haydock KP. A method for measuring the acaricide susceptibility of the cattle tick Boophilus microplus (can.). Bull Entomol Res. 1962;53:563–78.

22. Rodrigues-Vivas RI, Miller RJ, Ojeda-Chi MM, Rosado-Aguillar JA, TrinidadMartinez IC, Perez de Leon AA. Acaricide and ivermectin resistance in a field population of Rhipicephalus microplus (Acari: Ixodidae) collected from red deer (Cervus elaphus) in the Mexican tropics. Vet Parasitol. 2014;200:179–88.

23. Winston PW, Bates DH. Saturated solutions for the control of humidity in biological research. Ecology. 1960;41:323–37.

24. Henderson CF, Tilton W. Tests with acaricides against the brown wheat mite. J Econ Entomol. 1955;48:157–61.

25. Hall RD, Townsend LH Jr, Turner EC Jr. Laboratory and field tests to compare the effectiveness of organophosphorous, carbamate and synthetic pyrethroid acaricides against northern fowl mites. J Econ Entomol. 1978;71:315–8.

26. Crystal MM, DeMilo AB. Susceptibility of laboratory-reared northern fowl mites, Ornithonyssus sylviarum (Acari: Macronyssidae) to selected acaricides. Exp Appl Acarol. 1988;4:353–8.

27. Fletcher MG, Axtell RC. Susceptibilities of northern fowl mite, Ornithonyssus sylviarum (Acarina: Macronyssidae), and chicken mite (Acarina: Dermanyssidae), to selected acaricides. Exp Appl Acarol. 1991;13:137–42.

28. Abbas RZ, Colwell DD, Iqbal Z, Khan A. Acaricidal drug resistance in poultry red mite (Dermanyssus gallinae) and approaches to its management. World’s Poultry Sci J. 2014;70:113–24.

29. Elector® PSP Label. Elanco, Indianapolis, IN. 2011. labels/Dairy/Elector_PSP.pdf. Accessed 8 Dec 2016.

30. Murillo AC, Gerry AC, Gallagher NT, Peterson NG, Mullens BA. Laboratory and field assessment of cyantraniliprole relative to existing fly baits. Pest Manag Sci. 2014;71:752–8.

31. George DR, Shiel RS, Appleby WGC, Know A, Guy JH. In vitro and in vivo acaricidal activity and residual toxicity of spinosad to the poultry red mite, Dermanyssus gallinae. Vet Parasitol. 2010;173:307–16.

32. Elector Technical Manual. Elanco, Indianapolis. 2012. https://www. Accessed 8 Dec 2016.

33. Rohdich N, Roepke RKA, Zschiesche E. A randomized, blinded, controlled and multi-centered field study comparing the efficacy and safety of Bravecto™ (fluralaner) against frontline™ (fipronil) in flea- and tick-infested dogs. Parasit Vectors. 2014;7:83.

34. Williams H, Zoller H, Roepke RKA, Zschiesche E, Heckeroth AR. Fluralaner activity against life stages of ticks using Rhipicephalus sanguineus and Ornithodorus moubata in in vitro contact and feeding assays. Parasit Vectors. 2015;8:90.

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