Amy C. Murillo

Laboratory and field assessment of cyantraniliprole relative to existing fly baits

BACKGROUND Toxic fly baits are commonly used for fly control in California animal operations. However, resistance development has been a problem. Comprehensive laboratory and field studies were conducted to test commercial baits (imidacloprid, methomyl, dinotefuran, spinosad) and one novel cyantraniliprole bait. A susceptible Musca domestica strain was compared with wild-type M. domestica and Fannia canicularis strains in the laboratory using choice/no-choice tests. Field visitation to baits and both short- and longer-term mortality were documented. RESULTS Susceptible Musca suffered high mortality with all baits after 3 days of choice and no-choice tests. Wild-type Musca mortality was more variable and higher in no-choice relative to choice tests. Fannia were most susceptible to spinosad > dinotefuran = cyantraniliprole > methomyl = imidacloprid. Field Musca were most attracted to spinosad > cyantraniliprole > dinotefuran > sugar > methomyl > imidacloprid. Delayed mortality from bait-fed field flies (captured and held with untreated food and water for 3 days) was ranked spinosad = cyantraniliprole > dinotefuran = methomyl > imidacloprid > sugar. CONCLUSION Behavioral resistance of M. domestica to imidacloprid and methomyl persists. Spinosad and cyantraniliprole baits (delayed mortality) performed best. Speed of action may be a factor in use and misuse of baits.

Diversity and Prevalence of Ectoparasites on Backyard Chicken Flocks in California

Abstract Peridomestic (“backyard”) chicken flocks are gaining popularity in the developed world (e.g., North America or Europe), yet little is known regarding prevalence or severity of their ectoparasites. Therefore, five birds on each of 20 properties throughout southern California were surveyed in summer for on-host (permanent) and off-host dwelling (temporary) ectoparasites. Only four premises (20%) were entirely free of ectoparasites. In declining order of prevalence (% of premises), permanent ectoparasites included six chicken louse species: Menacanthus stramineus (Nitzsch) (50%), Goniocotes gallinae (De Geer) (35%), Lipeurus caponis (L.) (20%), Menopon gallinae (L.) (15%), Menacanthus cornutus (Schömmer) (5%), and Cuclotogaster heterographus (Nitzsch) (5%). Only one flea species, Echidnophaga gallinacea (Westwood) (20%), was found. Three parasitic mite species were observed: Ornithonyssus sylviarum (Canestrini & Fanzago) (15%), Knemidocoptes mutans (Robin & Lanquetin) (10%), and Dermanyssus gallinae (De Geer) (5%). Many infestations consisted of a few to a dozen individuals per bird, but M. stramineus, G. gallinae, M. cornutus, and E. gallinacea were abundant (dozens to hundreds of individuals) on some birds, and damage by K. mutans was severe on two premises. Off-host dwelling ectoparasites were rare (D. gallinae) or absent (Cimex lectularius L., Argasidae). Parasite diversity in peridomestic flocks greatly exceeds that is routinely observed on commercial chicken flocks and highlights a need for increased biosecurity and development of ectoparasite control options for homeowners.

The future of poultry pest management

Abstract There is an increasing interest in using pest and parasite control approaches for poultry production that minimize traditional synthetic pesticides, particularly in organic production. Housing choices, such as conventional or enriched cages, indoor cage-free options such as aviaries, or free range systems for laying hens, greatly impact pest complexes, their potential to cause damage, and effective control options. Additionally, more information is needed on pest occurrence and dynamics in these systems. Known (or likely) important poultry pests and parasites are presented and discussed along with potential chemical, cultural, and biological control options. Control materials available now or in the near future, such as novel synthetic materials, plant essential oils, and vaccines, are briefly reviewed. Pest monitoring is vital to decision making and has been underutilized. Integrated pest management hinges on knowledge of local pest abundance, pest biology, cost–benefit analyses, and potential for economic damage in commercial-scale production.

Field Distribution and Density of Culicoides sonorensis (Diptera: Ceratopogonidae) Eggs in Dairy Wastewater Habitats

Abstract Culicoides sonorensis Wirth and Jones (Diptera: Ceratopogonidae) is a key bluetongue virus vector in the United States. Immatures occur in mud near the edges of wastewater ponds and are understudied targets for control efforts. Eggs of C. sonorensis were collected in the morning from a dairy wastewater pond bank by taking 5-ml surface mud samples along four transects on each of six dates. Surface mud samples parallel to waterline (10-cm long, 1-cm wide, and 0.5-cm deep) were removed at 5-cm increments ranging from 15 cm below waterline up to 25 cm above waterline. Eggs were removed using MgSO4 flotation, held on moist filter paper, and scored for hatching over 3 d. Eggs hatching on days 2 and 3 were assumed to have been laid on the test night. Water levels were stable within a night according to time-lapse camera photos. Most samples from below the waterline had no eggs and were not analyzed statistically. Mean (±SE) sample moisture (25.8 ± 2.1 at 5 cm above waterline and 19.8 ± 2.6% at 25 cm above waterline) did not vary significantly by position above waterline. The highest density of viable eggs (21 eggs/5 ml), proportion of mud samples positive for viable eggs (75%), and proportion of eggs hatching (80%) were found 5 cm above waterline. Oviposition in the few hours after sunset is adaptive, allowing eggs to age, develop the serosal cuticle, and resist later desiccation. As a potential control method, reducing water levels after midnight would encourage young egg desiccation.

A review of the biology, ecology, and control of the northern fowl mite, Ornithonyssus sylviarum (Acari: Macronyssidae)

The northern fowl mite, Ornithonyssus sylviarum (Canestrini & Fanzago, 1877), is found on several continents and has been a major pest of poultry in the United States for nearly a century. Lack of earlier USA reports in the United States suggests an introduction or change to pest status in domestic poultry systems occurred in the early 1900s. Though predominantly a nest-parasite of wild birds, this obligate hematophagous mite is a permanent ectoparasite on domestic birds, especially egg-laying chickens. Economic damage is incurred by direct blood feeding and activation of the of hosts immune responses. This in turn causes decreased egg production and feed conversion efficiency, and severe infestations can cause anemia or death to birds. Here we review the biology, ecology, and recent control measures for the northern fowl mite. Photomicrographs are included of adult males and females, protonymphs, and larvae with key characters indicated. Special emphasis is placed on current knowledge gaps of basic and applied science importance.

Timing Diatomaceous Earth-Filled Dustbox Use for Management of Northern Fowl Mites (Acari: Macronyssidae) in Cage-Free Poultry Systems

Northern fowl mite management on conventionally caged birds relies on synthetic pesticide sprays to wet the vent. Cage-free chickens cannot be effectively treated this way, and pesticide use is restricted in organic production. Dustbathing behavior is encouraged in newer production systems for increased hen welfare. Diatomaceous earth (DE) is an approved organic insecticide that can be mixed with sand in dustboxes, suppressing mites but not excluding them, and potentially allowing development of mite immunity. We tested two hypotheses: 1) that DE-filled dustboxes placed before northern fowl mite introduction (prophylactic use) prevents mite populations from reaching economically damaging thresholds, and 2) that bird exposure to low mite numbers allows for protective hen immunity to develop and suppress mites after dustboxes are removed. We also tested if different beak trimming techniques (a commercial practice) affect mite growth. Mites were introduced to birds after dustboxes were made available. Average mite densities in flocks remained below damaging levels while dustboxes were available. Average mite populations rebounded after dustbox removal (even though DE persisted in the environment) regardless of the timing of removal. Mite densities on birds where a traditional hot-blade beak trimming technique was used (trial 1) were high. Mite densities in trial 2, where a newer precision infra-red trimming was used, were lower. The newer infra-red trimming method resulted in nearly intact beaks, which were better for mite control by bird grooming behaviors. The combination of early dustbox use and infra-red beak trimming should allow producers to avoid most mite damage in cage-free flocks.

Sulfur Dust Bag: A Novel Technique for Ectoparasite Control in Poultry Systems

Abstract Animal welfare-driven legislation and consumer demand are changing how laying chickens are housed, thus creating challenges for ectoparasite control. Hens housed in suspended wire cages (battery cages) are usually treated with high-pressure pesticides. This application type is difficult in enriched-cage or cage-free production. Alternatives to pesticide sprays are needed in enriched-cage or cage-free systems. In this study, we tested the efficacy of sulfur dust deployed in “dust bags” for control against the northern fowl mite (Ornithonyssus sylviarum), which causes host stress, decreased egg production, and reduced feed conversion efficiency. Dust bags were hung from the tops of cages or were clipped to the inside front of cages. We also tested permethrin-impregnated plastic strips, marketed for ectoparasite control in caged or cage-free commercial and backyard flocks. Previous work has shown sulfur to be very active against poultry ectoparasites; however, we found that the placement of bags was important for mite control. Sulfur in hanging bags reduced mites on treatment birds by 95 or 97% (depending on trial) within one week of being deployed, and mite counts on these birds were zero after 2 wk. Clipped sulfur bags acted more slowly and did not significantly reduce mites in one trial, but reduced mite counts to zero after 4 wk in trial 2. Permethrin strips had no effect on mite populations. This may have been due to mite resistance, even though this mite population had not been exposed to pyrethroids for several years. Sulfur bags should be effective in caged or cage-free systems.

Parasites in Laying Hen Housing Systems

Abstract In this chapter the life cycles of selected principal internal and external parasites and pests of laying hens are presented including photographs of organisms and typical signs of infestation. Parasites are categorized according to whether they are (1) permanent parasites (e.g., coccidia, intestinal nematodes, and northern fowl mites), (2) spend only part of their lives as on-host parasites (e.g., sticktight fleas and red mites), or (3) are environmental pests which actually only live in close association with hens (e.g., darkling beetles and houseflies). Hen housing and management are subject to animal welfare concerns as well as public attitudes regarding pesticide use. This chapter approaches parasite prevalence and management from the standpoint of how they are impacted by housing. Parasites are rated for their severity in different housing types, and approaches to their control in those types of facilities are discussed.