Recipient Organization
UNIVERSITY OF CALIFORNIA, RIVERSIDE
(N/A)
RIVERSIDE,CA 92521
Performing Department
Entomology, Riverside
Non Technical Summary
The northern fowl mite (NFM) is a widespread poultry pest that is economically damagingcommercial poultry in the United States. Worldwide the poultry red mite (PRM)is the most economically important ectoparasite of poultry. Both NFM and PRM feed on chicken blood which causes damage to bird health, welfare, and economic output. NFM and PRM are endemic to the US and are parasites of wild birds as well as domestic poultry.One challenge facing poultry producers is how to treat NFM and PRM, especially in cage-free or organic production. The goal of this study is to test acaricides from several different modes of action (Insecticide Resistance Action Committee,http://www.irac-online.org). Insecticide resistance can be avoided by rotating compounds with different modes of action. Some of the compounds to be tested have been used to control citrus and other plant mites, with the hope of discovering a new (to poultry) treatment option. Compounds which could be used in organic production will also be tested.In this project we will:1) Test the efficacy of acaricides with different modes of action against field populations of NFM and PRM.2) Develop and distribute extension products focused on mite biology, prevention, and management to US stakeholders. NFM and PRM management recommendations will consider bioassay results.
Animal Health Component
100%
Research Effort Categories
Basic
(N/A)
Applied
100%
Developmental
(N/A)
Goals / Objectives
The northern fowl mite (NFM; Ornithonyssus sylviarum) is a widespread poultry pest that is particularly important for commercial poultry in the United States (Murillo and Mullens 2017). These mites are obligate blood feeders that spend most of their time on-host. Worldwide the poultry red mite (PRM), Dermanyssus gallinae, is the most important ectoparasite of poultry (Sparagano et al. 2009). Poultry red mites are also obligate blood feeders that cause damage to bird health, welfare, and economic output. Both NFM and PRM are endemic to the US and are parasites of wild birds as well as domestic poultry (Murillo and Mullens 2016). Poultry red mites have not been a pest in over 70 years in the US because of the use of wire cages for egg production, but this is rapidly changing. For example, in California Proposition 2 banned small wire cages for egg production and California's Proposition 12 eliminates the use of cages by 2022. However, increased cage-free egg production is a nation-wide trend, and it is estimated that over the next decade at least 40% of poultry will be housed in cage-free alternatives (Egg Industry, Feb 2016). The goal of this study is to test acaricides from several different modes of action (Insecticide Resistance Action Committee, http://www.irac-online.org). Insecticide resistance can be avoided by rotating compounds with different modes of action. Some of the compounds to be tested have been used to control citrus and other plant mites, with the hope of discovering a new (to poultry) treatment option. Compounds which could be used in organic production will also be tested.In this project we will:1) Test the efficacy of acaricides with different modes of action against field populations of NFM and PRM.2) Develop and distribute extension products focused on mite biology, prevention, and management to US stakeholders. NFM and PRM management recommendations will consider bioassay results.
Project Methods
Objective 1: Mites from 10 different properties (populations) throughout CA and the US will be used for acaricide screening. We will work with poultry extension agents, veterinary entomologists, poultry veterinarians, pest control operators, and poultry producers to identify NFM and PRM populations. Mites are easily caught using cardboard traps (e.g. Lammers et al. 2017). Traps will be shipped overnight to UCR for use in bioassays. All mites received will have their identity confirmed by microscopy (Murillo and Mullens 2017). Only the US state each collection came from will be recorded to preserve the anonymity of participating flocks.The compounds to be tested will be in different chemical classes with different modes of action (Table 1). These include: tetrachlorvinphos/dichlorvos (organophosphate), permethrin (pyrethrin), fenbutatin oxide (organotin miticide), hexythiazox (growth regulator), spirodiclofen (lipid synthesis inhibitor), diethylaminobenzaldehyde (detergent), and thyme essential oil. Both the detergent and essential oil treatments would potentially be allowed for use in organic production.Table 1. Seven chemical treatments from different chemical classes will be tested for efficacy against field collected NFM and PRM populations.TreatmentChemical ClassMode of ActionIRAC codetetrachlorvinphos/dichlorvosorganophosphateAcetylcholinesterase inhibitors1BpermethrinpyrethrinSodium channel modulators3Afenbutatin oxideorganotin miticideInhibitors of mitochondrial ATP synthase12Bhexythiazoxgrowth regulatorMite growth inhibitors10Aspirodiclofenlipid synthesis inhibitorInhibitors of acetyl CoA carboxylase.23diethylaminobenzaldehydedetergentLikely disrupts respiration and/or cuticlen/aThyme essential oilessential oilunknownn/aGlass pipettes (146 mm) will be used for the bioassays. Each pipette will be coated with a chemical to be tested. The stock solution for each chemical will be prepared according to the commercial label rate. For chemicals that do not have a label rate for poultry mites, preliminary testing on the UCR NFM colony will be completed using several concentrations based on current literature (e.g. Abdelfattah et al. 2018 for thyme essential oil). Chemicals are diluted into either a water or an ethanol carrier, so a water-only and ethanol-oil control will be included.Each chemical will be drawn up into a pipette, expelled, then allowed to dry overnight on a shaker table to ensure even coverage as the chemical dries (Mullens et al. 2004). For each chemical treatment five pipettes will be used. There will be a total of seven treatments and two controls (one water only, one ethanol only) tested for each mite population.Mites will be tested within 5 d of being collected. Twenty adult mites will be collected into each (treated) pipette (Mullens et al. 2004). Mite mortality will be assessed under a microscope at 2, 4, 24 and 48 h.Probit analyses, often used for survival comparisons (e.g., Mullens et al. 2004), will be used to make comparisons among treatments for each population (per species) or among populations for each treatment (per species).Objective 2: Integrated Pest Management (IPM) plans provide guidance for stakeholders in order to reduce the economic damage caused by pest arthropods. The PRM is a reemerging pest and mites generally are very difficult to eradicate once they are introduced to a property, so IPM efforts will be vital to control both species. It will be important to first provide information on the basic biology and life history of the mites and compare and contrast the PRM with other more well-known poultry ectoparasites that US poultry producers will be familiar with. In our experience, both PRM and NFM can be found in the same flock, so it will be important for producers to know the differences in monitoring and management techniques for these related but distinct species.The results from the bioassays will provide information on effective chemical controls for NFM and PRM. NFM are primarily an on-host pest, and birds in caged housing systems (and some aviaries) can be sprayed directly for NFM control. However, these types of on-animal sprays are less practical for other cage-free housing systems. Recent work provides strong evidence that once NFM are introduced to a property these same populations reinfest future flocks (i.e., there are not repeated mite introductions; McCulloch et al. 2020). Therefore, it is very important to thoroughly clean, disinfect and treat houses to eliminate NFM that carryover in between flocks. Followed by proper biosecurity, future flocks can remain NFM-free. This same principle of treating houses in between flocks is very important for PRM infestations, especially because they are better adapted for survival in the absence of birds.The results of the bioassay will not only inform producers on what chemicals are effective but can also provide a warning if acaricide resistance is detected. Chemical treatments can be expensive (product and labor costs), and the detection of acaricide resistance can warn producers to test a small subset of the mite population before treating an entire poultry house or property. In addition, general education on the topic of acaricide resistance and how to avoid it (i.e. chemical class rotation) will be provided in education materials.