Mite fauna ( Acari ) associated to commercial laying hens and bird nests in Vale do Taquari , Rio Grande do Sul , Brazil

The control of ectoparasites is essential for maintaining biosafety in a poultry farm. This paper aimed to analyze the mite fauna associated to abandoned nests and commercial laying hens in the towns of Lajeado and Teutônia, Vale do Taquari, Rio Grande do Sul, Brazil. Samplings were conducted from December 2010 to July 2011. A total of 11,757 mites belonging to 21 families and 31 species were found. Cheyletidae showed the highest number of species (4), followed by Blattisocidae (3 species). Dermanyssus gallinae (De Geer) showed the highest number of individuals (5,689), followed by Megninia gynglimura Mégnin (2,175), and Chortoglyphus arcuatus Troupeau (1,488). Blattisocius tarsalis Berlese, C. arcuatus, and D. gallinae were found on traps, feathers, poultry farm nests without cages (free), and abandoned bird nests.


Introduction
The laying hens, free and wild birds may carry pathogenic organisms and ectoparasites to the farms linked to commercial aviculture.Although the Ministério da Agricultura, Pecuária e Abastecimento (MAPA) try to control the presence of birds and other animals on poultry farms, is unlikely to be able to eradicate wild birds from nearby farms.The integral control of people and objects, flux and ectoparasites is essential for the maintenance biosecurity.The absence of these controls increases the diseases risk (BORNE;COMTE, 2003).
Dermanyssus gallinae (De Geer) (Dermanyssidae) also known as the poultry red mite (PRM), is an epidemiological and economical problem for the poultry industry worldwide.This ectoparasite is hematophagous and is responsible for egg downgrading and spotting, anaemia in birds and more reports suggest it could be a etiologic agents vector of several human and animal diseases.It is the most important ectoparasite affecting laying hens (CHAUVE, 1998).Megninia ginglymura (Mégnin) (Analgidae) is an ectoparasite found in bird feathers (FLECHTMANN, 1985).Their saliva causes allergic reactions, stress and the itching leads to the development of petechiae hemorrhagic, vesicles and the crust formation on the site providing secondary bacterial infections and pyorderma (TUCCI et al., 2005).Studies with the aim of finding a natural predator to D. gallinae, in their natural habitat, were developed by Lesna et al. (2009), in samples by nests abandoned Sturnus vulgaris (Linnaeus) (Sturnidae) in the Netherlands.Currently, studies on population dynamics and efficient techniques for the control of hematophagous mites are scarce in Brazil.Until now, nothing is known about the mite fauna associated to D. gallinae and commercial laying birds in Rio Grande do Sul.Due to the importance of this activity to the economy of Taquari Valley and state, it is necessary to know the associated mites, their frequency and damages caused by them.Moreover, it is essential to know what laying hens and wild birds are carriers of the pest mites for poultry houses.In this context also arises the need to improve certain methods of control of ectoparasites in the productive system of commercial laying eggs, because the market is demanding new processes and methodologies that focus on product quality, environmental, worker health and rural animal welfare.This study investigates the mite fauna associated to bird's nests abandoned and commercial laying hens of poultry egg-laying business.

Materials and Methods
This study was conducted in birds' nests abandoned and egg-laying poultry commercial between December 2010 to July 2011 in Lajeado and Teutônia Counties, in Taquari Valley, Rio Grande do Sul, Brazil.The abandoned nests were stored in plastic sacks, kept refrigerated and sent to the Acarology Laboratory, University Center UNIVATES to realize the extraction of mites.Mites found were collected with fine-tipped paintbrush and mounted with Hoyer's medium on microscopic slides (WALTER-KRANTZ, 2009).
In Lajeado were collected a Hylocharis sp.(hummingbird) nest; nearby of UNIVATES University Center, a Troglodytes musculus (Naumann) (southern house wren) and hummingbirds nests and in Teutônia two Turdus rufiventris Vieillot nests (rufous-bellied thrush).To identify these birds was used Belton (1994) and the birds were monitored and identified before to abandon the nest.Four poultry houses were sampled in Teutônia in wooden sheds, being what in two, the birds were kept metal cage battery (Cage) and the other two, the birds were raised free, on wooden pallet with nests and roosts disposition, with feeders tubular and drinkers pendulous and with free access to farm courtyard, where they took the sun, flying, wings beating, running, pecked and revolved along the ground (Free range).In cage system, to make samples were prepared cardboard traps with 100 mm width x 70 mm length x 3 mm height, as suggested by Cunha et al. (2009).The cardboard traps were distributed near the superior vertex, sides and in front of the cages selected randomly; in free range system of traps were placed on roosts, nests, columns and walls, following the method used by Lesna et al. (2009).The traps were changed every 15 days and always fixed at the same point.These traps, without acaricides, usually try to imitate the hiding places searched by D. gallinae, facilitating their capture (CHIRICO; TAUSAN, 2002).

Mitefauna associated to commercial laying hens and birds' nests
In each poultry house were exposed five traps, totaling 20 traps every 15 days following by Lesna et al. (2009).After the exposure period, traps were collected and placed in plastic bag, identified and kept under refrigeration in laboratory until the realization of screening material.Five nests were sampled in Free range system, where was collected a portion of nest substrate, placed on identified plastic bag and moved to laboratory.
To identify the mites present in the feathers were removed three feathers from nine birds to each poultry house, totalizing 108 feathers/month/poultry house.Hughes (1976) and Flechtmann (1985) were used to identify the species.Voucher specimens were deposited in mites reference collection of the Museum of Natural Sciences -University Center UNIVATES (ZAUMCN), Lajeado, Rio Grande do Sul.

Results
A total of 11,757 mites belonging to 21 families and 31 species were found.Most, about 99% of specimens were collected in poultry house, in Teutônia.The Cheyletidae showed increased number of species, with four species and Blattisocidae, with three species.Acaridae, Glycyphagidae, Laelapidae and Phytoseiidae had two species.Dermanyssidae show higher abundance, with 5,689 specimens, followed by Analgidae with 2,175 and Chortoglyphidae with 1,488.Pyroglyphus sp. was collected only in feathers, while M. gynglimura was found in feathers, traps and poultry farm nests in free range system.Blattisocius tarsalis (Berlese), Chortoglyphus arcuatus (Troupeau) and D. gallinae, they are also found in the traps, on feathers, poultry farm nests in both system and also in abandoned bird's nest.
The mite species and the environments where found collected are presented below, along with the municipality, month and year of collection.Specimens' numbers are showed in parentheses.

Suborder Mesostigmata
Blattisocidae Garman, 1948 Comments: Blattisocius dentriticus feeds eggs of other arthropods and T. putrescentiae (FENILLI; FLECHTMANN, 1990).Species associated with imported food in the United States (HUGHES, 1976).Blattisocius dentriticus is a predator that competes with Cheyletus eruditus (COLLINS, 2012).Comments: Blattisocius keegani control beetles in stored products.There are evidences that this species feeds on lepidopteran eggs and present potential for biological control of fly larvae in orange (THOMAS et al., 2011).Comments: Blattisocius tarsalis has been used in biological control in flour mills, because it acts effectively on the flour moth (Ephestia kuehniella) (Zeller) (Lepidoptera: Pyralidae) (NIELSEN, 1998).This species is known as predatory larvae of insects in stored grain (TREAT, 1969) Comments: Kleemania plumigera may occur in hay warehouses in debris and crumbling walls in new buildings, but in this environment, usually disappears once the area becomes drier.It has also been found in reused litter (HUGHES, 1976).In studies between 2000 and 2006, in Greece, met Kleemania plumigera on farms and in environments of agricultural cooperatives (PALYVOS et al., 2008).

Dermanyssidae Kolenati, 1859
Dermanyssus gallinae (De Geer, 1778) Acarus gallinae De Geer, 1778.Comments: Dermanyssus gallinae is a health and economic problem in commercial laying poultry.Injuries during its blood meal can be identified on chest and legs of birds (TUCCI; GUIMARÃES, 1998).Causes stress, theft, due to hematophagous activity, anemia, and decrease in egg production and may also be a vector of pathogenic microorganisms (BACK, 2004).
Comments: Hypoaspis aculeifer feeds on other mites, small insects and nematodes.Their larvae don´t feed and adult forms may eat their own eggs.It feeds also T. putrescentiae (ZHANG, 1963) and immature of D. gallinae (LESNA et al. 2009).
Comments: Macrocheles muscaedomesticae is a predator (LESNA et al., 2009) of house fly and related species.It is found in manure, including poultry manure, habitat conducive to the development of flies.Larvae and adults feed on the eggs of flies.It is common to find female M. muscaedomesticae in stored food or in any other place where have flies (ZHANG, 1963).
Comments: This species was collected from native vegetation and vines in the state of Rio Grande do Sul (FERLA;MORAES, 2002;FERLA et al., 2011).
Comments: They are mites that live in forests, fertile soil and manure.They feed on bread, yeast and immature stages of flies.These mites are phoretic, attach to the surface of their prey.There are studies reporting that some uropodinas are carnivores (GERSON; SMILEY, 1990).
Comments: Cheyletus eruditus has been observed feeding on young forms of D. gallinae (MAURER;HERTZBERG, 2001).Cheyletus eruditus practice cannibalism in the absence of food, or when kept with food with low nutritional value.There are reports of stored grains containing only C. eruditus without any prey (CEBOLLA et al., 2009).
Comments: Cheyletus malaccensis is related to biological control of prey and has proved very effective in controlling Lepidoglyphus destructor and T. putrescentiae.This mite also practiced cannibalism in the absence of food, or when kept with food with low nutritional value (CEBOLLA et al., 2009).
Comments: Megninia ginglymura feeds the feathers of birds infested.The mite's saliva causes an allergic reaction, stress, and intense itching, which leads to the formation of crusts, facilitating secondary bacterial infections and pyoderma.The itching may cause petechiae and hemorrhagic blisters on the skin of the bird parasitized (TUCCI et al., 2005).
Comments: Chortoglyphus arcuatus is a mite identified in dust samples mattress, is commonly found in rural areas of Central Europe, being responsible for allergies in farmers (SCHULZ et al., 2004).
Comments: Blomia tropicalis is associated with occupational asthma in farmers and grain handlers.It occurs in tropical and subtropical regions in dust.In the United States, is very common in dust from mattresses and carpets of houses (ARRUDA; CHAPMAN, 1992).In Rio Grande do Sul was found in residences (FERLA; NEUMANN, 2004).
Comments: Ctenoglyphus plumiger occurs in barns, wheat, oats and barley, grass seed, and sometimes appears in large populations, in the hay.It has been found in fish meal and honeycombs (HUGHES, 1976).Comments: Lepidoglyphus destructor occurs worldwide in stored grains and also in animal feed.In periods of high humidity, especially in hay stored, there may be rampant infestation, reaching 50,000 mites per kg of hay.In addition to economic losses, the mite is a public health problem, since it may be responsible for cases of occupational diseases such as asthma among rural workers (KNÜLLE, 1991).
Comments: Pyroglyphus sp. is found in the nests of rodents and birds (HUGHES, 1976).
Mitefauna associated to commercial laying hens and birds' nests
Comments: Oribatids mites are common in the soil.They feed on fungi and fallen plants, are important in decomposition and soil formation.There are few species that live in the aerial parts of plants, but still has economic importance because they are known as plant pests (ZHANG, 1963).

Discussion
The biological control of mite pests by natural predators can help reduce high infestations, preventing that these ectoparasites becoming a health and economic problem.Lesna et al. (2009) commented that, as the eggs are produced for human consumption must meet stringent food safety standards, in other words, the eggs must be free of debris and for the use of acaricide products, there must be a rapid degradation of the compounds used for components which are not harmful.Also commented that the products cannot be harmful to health or well being of the squad.In spite of using chemical sprays directly on the birds, the synthetic acaricides currently used has limitations as well as unfeasibility eradication and residues presence in eggs, because the red mite spends most of the time housed in their hiding places, places where spraying will hardly reach (LESNA et al., 2009).These authors in Dutch provinces, found in birds' nests D. gallinae, A. casalis, C. eruditus and L. destructor.These specimens were also found in Teutônia poultry houses and in abandoned nests collected in Taquari Valley, Rio Grande do Sul, Brazil.
Our results highlighted on commercial hen´s nests a high predator population belonging to Cheyletidae and Cunaxidae families if compared with Lesna et al. (2009).Eucheyletia reticulata is the first citation of this species in the state of Rio Grande do Sul and, according to Cebolla et al. (2009), Cheyletus malaccensis is reported like a biological agent controlling effectively L. destructor and T. putrescentiae.In this work it may be feeding of Tyrophagus putrescentiae in nests or Dermanyssus gallinae.Rubroscirus nidorum is the first species of the genus to be described for commercial laying hens.
This study showed that specimens collected in abandoned nests of birds can also be seen in poultry farm for commercial egg laying excepting specimens of Pyroglyphus sp. on feathers which was found in specific places.Thus, it is concluded that wild birds are often similar mitefauna of the natural environment for commercial poultry farms.The access restriction to farm of wild birds could reduce limit the entry of mite disseminators of diseases, causing economic losses to farmers and the poultry industry.

FIGURE 2 :
FIGURE 2: Mites found in abandoned bird's nest between December 2010 to July 2011 in Lajeado and Teutônia Counties, Rio Grande do Sul, Brazil.
G. L. Silva et al.