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

Abstract

Dermanyssus gallinae (De Geer, 1778) is a major problem for the poultry industry worldwide, as it negatively affects virtually all kinds of rearing systems. Therefore, the control of infestation has become a routine process, and its economic cost is constantly increasing. Until now, most of the control strategies have relied on the use of synthetic chemical drugs, but their efficacy is often questioned by the emergence and diffusion of resistant mite populations. With this in mind, the efficacy of λ-cyhalothrin, amitraz, and phoxim has been verified by testing them against 86 mite populations collected from the same number of poultry farms in Italy from 2008 to 2015. Assays were performed according to the filter paper method using the recommended, half, quarter, double and quadruple doses. The results showed that phoxim and amitraz were the most effective acaricides (median efficacies 80.35% and 80.83%, respectively), but amitraz exhibited a sharp fall in its efficacy during 2011 and 2012, while phoxim maintained its high effectiveness up to 2015, when it dropped. The overall median efficacy of λ-cyhalothrin was 58.33%. The data also highlighted the importance of the use of the right concentration, as an increase in dosage was not always useful against resistant populations, while its reduction also diminished efficacy, simultaneously increasing the risk for the development of resistance.

Miticidal activity of fenazaquin and fenpyroximate againstVarroa destructor, an ectoparasite ofApis mellifera

“…To expedite the search for a new Varroacide, it is advantageous to evaluate compounds already used in other agriculture and domestic animal industries. In the case of amitraz, for example, it was originally formulated for use on mammals for the removal of mites and ticks 40–42 . After testing this compound on honey bees and Varroa mites, it was found to be an effective Varroacide and it is now used as the active ingredient (AI) of the in‐hive treatment Apivar.…”

“…In the case of amitraz, for example, it was originally formulated for use on mammals for the removal of mites and ticks. 40 , 41 , 42 After testing this compound on honey bees and Varroa mites, it was found to be an effective Varroacide and it is now used as the active ingredient (AI) of the in‐hive treatment Apivar. Indeed, there are other miticides with differing MOAs that have already been developed to control mites and ticks in North America that could be screened for use on Varroa .…”

Challenges for the Control of Poultry Red Mite (Dermanyssus gallinae)

“…The number of PRM populations with reduced sensibility to traditional pesticides as λ-Cyhalothrin or Amitraz has grown especially after 2012. In the case of Phoxim, which has been considered a highly effective compound, highly resistant populations have been detected since 2015 [70]. This is probably related to withdrawal of most of the labeled compounds from the marked and subsequent overuse and misuse of the only remaining products available.…”

Dermanyssus gallinae: the long journey of the poultry red mite to become a vector

“…The control strategies mostly rely on the application of synthetic or semisynthetic acaricides [ 8 ], with phoxim, fluralaner and spinosad being among the few acaricides authorized worldwide [ 9 ]. However, the development of mite populations resistant to these chemical compounds has often led farmers to use unauthorized drugs, such as amitraz or fipronil, which could be harmful to human health [ 10 ].…”