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

Abstract

BackgroundNorthern 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.MethodsSix 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 h at 75% relative humidity and a temperature of 22 °C.ResultsAdult mite LC50 /LC99 values were 2.95/8.09 ppm for fluralaner, 1587/3123 ppm for spinosad, 420/750 ppm for phoxim and 86/181 ppm for propoxur. Permethrin and deltamethrin LC values could not be calculated due to lack of mortality observed even at 1000 ppm.ConclusionsNorthern 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.Electronic supplementary materialThe online version of this article (doi:10.1186/s13071-017-2289-z) contains supplementary material, which is available to authorized users.

In vitro activity of fluralaner and commonly used acaricides against Dermanyssus gallinae isolates from Europe and Brazil

“…Results from the studies described in this report show that fluralaner is active against poultry red mites, isolated from commercial operations, showing decreased susceptibility to the most commonly used acaricides. These findings are consistent with reports of fluralaner efficacy against Ornithonyssus sylviarum , the northern fowl mite, particularly prevalent in North and Latin America, at similar exposure rates as those to which D. gallinae is sensitive [ 34 ]. They also align with previous results showing that fluralaner has been shown to overcome resistance in fleas, ticks or sea lice against phenylpyrazoles, amidines, organophosphates, cyclodienes, macrocyclic lactones, phenylpyrazoles, benzophenyl ureas, pyrethroids and carbamates [ 35 ].…”

Efficacy ofλ-cyhalothrin, amitraz, and phoxim against the poultry red miteDermanyssus gallinaeDe Geer, 1778 (Mesostigmata: Dermanyssidae): an eight-year survey

“…This could account for the early rise of resistant D. gallinae populations, which was firstly documented more than 20 years ago (Beugnet et al, 1997) and it has been repeatedly reported from mites collected in poultry farms (Nordenfors et al, 2001;Thomas et al, 2018). A similar trend was observed for O. sylviarum populations collected in the field in California (Mullens et al, 2017).…”

Assessment of fluralaner as a treatment in controlling Dermanyssus gallinae infestation on commercial layer farms and the potential for resulting benefits of improved bird welfare and productivity

“…Fluralaner is an isoxazoline compound that is approved for the treatment of poultry red mite infestations by two drinking-water administrations with a 7-day interval and having egg and meat withholding times of 0 and 14 days, respectively [ 12 ]. In vitro studies have demonstrated that field isolates of the northern fowl mite ( Ornithonyssus sylviarum ) and the PRM that are highly sensitive to fluralaner are relatively insensitive to other compounds, including spinosad, phoxim, propoxur and deltamethrin [ 13 , 14 ]. The mite-killing activity of fluralaner is evident within 4 h of the first administration and is maintained for at least the next 14 days [ 15 ].…”