Low levels of chicken body louse (Menacanthus stramineus) infestations affect chicken welfare in a cage-free housing system.

BACKGROUND: The chicken body louse is an obligate ectoparasite of domestic chickens. Chicken body lice feed on feathers, and infestation with this louse is linked to decreases in egg production, hen weight, and feed conversion efficiency. However, it is unknown how chicken body lice impact egg-laying chickens in cage-free environments. Welfare and behavior metrics were collected from flocks of egg-laying chickens either infested with chicken body lice or left uninfested. METHODS: In two trials, two flocks of cage-free commercial egg-laying chickens were infested with chicken body lice or maintained as uninfested controls. At three timepoints, behavior and welfare of all chickens was measured. On-animal sensors were used to quantify pecking, preening, and dustbathing behavior. Other animal-based welfare metrics included recording comb wounds and skin lesions. RESULTS: Birds infested with chicken body lice exhibited significantly more preening behaviors than uninfested birds, even at low louse levels. Moderate or severe skin lesions were detected on birds that were moderately infested with chicken body lice while skin lesions were never detected on uninfested birds. CONCLUSIONS: The welfare of chickens was impacted by the chicken body louse, a chewing louse that primarily feather feeds. Evidence of skin lesions on infested birds suggests that lice may cause more damage to birds than previously thought, and further evaluation of louse economic damage is necessary.

PRELIMINARY EXPERIMENTATIONS ON THE IN VITRO REARING OF HEMATOPHAGOUS PIGEON LOUSE HOHORSTIELLA LATA (AMBLYCERA: PHTHIRAPTERA: INSECTA).

Rearing hematophagous amblyceran lice in vitro is a challenging task. The hematophagous nature and active habits of amblycerans are distinct hurdles to in vitro rearing. The literature indicates only limited success in rearing the hematophagous amblyceran avian louse. Herein we report on the results of in vitro experimentation on an amblyceran pigeon louse, Hohorstiella lata. The incubation period of eggs was 5.47 ± 0.52 days. The durations of first, second, and third nymphal instars were 5.14 ± 0.55, 5.65 ± 0.83, and 6.35 ± 0.82 days, respectively. The average lifespan of adult females (7.45 ± 5.88 days) was higher than adult males (4.61 ± 3.57 days). Adult females laid a lifetime average of 3.73 eggs at a rate of 0.45 eggs/female/day under in vitro conditions (35 ± 1 C, 75-82% relative humidity, feather diet).

Sex interacts with age-dependent change in the abundance of lice-infesting Amur Falcons (Falco amurensis).

Sex-biassed and age-biassed parasite infections are common in nature, including ectoparasites-vertebrate host systems. We investigated the effect of Amur Falcons' sex, age and body size on the abundance of their lice at a migratory stopover site, where the falcons' habitat use and behaviour are more homogeneous across sex and age categories than during the breeding season. We sampled Amur Falcons in Nagaland, India at major roosting sites in 2016. We applied generalized linear models (with negative binomial distribution and log-link) to model the abundance of their two most numerous lice (Colpocephalum subzerafae and Degeeriella rufa) using the host age category (juvenile or adult) and wing length, both in interaction with sex, as explanatory variables. The abundance of C. subzerafae was only affected by host age, being nearly four times higher on juveniles than on adults. Juveniles were also more infested with D. rufa than the adults. Additionally, the abundance of the latter species was lower on adult male Falcons as compared to adult females. A juvenile bias in ectoparasite infestations is common in nature, probably due to juveniles being immunologically naïve, more resource-limited and may be inexperienced in body maintenance behaviours like preening and grooming. On the other hand, female-biassed infestations are much rarer than male-biassed infestations. We briefly discuss the possible causes of female-biassed infestations on Amur Falcons reported here, and in the closely related Red-footed Falcon and Lesser Kestrel as reported in the literature.

Chewing lice from high-altitude and migrating birds in Yunnan, China, with descriptions of two new species of Guimaraesiella.

In total, 366 birds representing 55 species in 24 families and eight orders, were examined for chewing lice (Phthiraptera: Amblycera, Ischnocera) in two high-altitude localities in Yunnan Province, China. In Ailaoshan, almost all of the birds examined were resident passeriforms, of which 36% were parasitized by chewing lice. In Jinshanyakou, most birds were on migration, and included both passerine and non-passerine birds. Of the passerine birds caught in Jinshanyakou, only one bird (0.7%) was parasitized by chewing lice. The prevalence of Myrsidea and Brueelia-complex lice on birds caught in Ailaoshan was higher than in previous reports. Of the chewing lice identifiable to species level, three represent new records for China: Actornithophilus hoplopteri (Mjöberg, 1910), Maculinirmus ljosalfar Gustafsson & Bush, 2017 and Quadraceps sinensis Timmermann, 1954. In total, 17 new host records are included, of which we describe two as new species in the Brueelia-complex: Guimaraesiella (Cicchinella) ailaoshanensis sp. nov. ex Schoeniparus dubius dubius (Hume, 1874) and G. (C.) montisodalis sp. nov. ex Fulvetta manipurensis tonkinensis Delacour & Jabouille, 1930. This published work has been registered in ZooBank, http://zoobank.org/urn:lsid:zoobank.org:pub:9FC3D8EE-2CED-4DBE-A1DB-471B71260D27.

The chewing lice (Phthiraptera: Ischnocera, Amblycera) of the great cormorant (Phalacrocorax carbo).

The Great Cormorant is a widespread bird species with almost worldwide distribution. Accordingly, its general biology has been investigated thoroughly. Less well known, however, are the chewing lice that live inside the plumage of this diving bird. We examined the two known species of Great Cormorant chewing lice, Eidmanniella pellucida (Rudow, 1869) (Amblycera: Menoponidae) and Pectinopygus gyricornis (Denny, 1842) (Ischnocera: Philopteridae). Taking advantage of the autofluorescence of the cuticle, confocal laser scanning microscopy (CLSM) was used to explore the external morphology of all developmental stages of P. gyricornis. Morphometric analyses revealed a standard increase in body size from first larval instar to the adult. In addition, all instars exhibited increasing body segment differentiation, especially in the abdomen and the head. A total of 277 individuals of Pectinopygus gyricornis and 2 individuals of Eidmanniella pellucida were collected from eleven Great Cormorants from Mecklenburg-Western Pomerania, Germany, in 2015.

Chewing lice from wild birds in northern Greece.

Greece represents an important area for wild birds due to its geographical position and habitat diversity. Although the bird species in Greece are well recorded, the information about the chewing lice that infest them is practically non-existent. Thus, the aim of the present study was to record the species of lice infesting wild birds in northern Greece and furthermore, to associate the infestation prevalence with factors such as the age, sex, migration and social behaviour of the host as well as the time of the year. In total 729 birds, (belonging to 9 orders, 32 families and 68 species) were examined in 7 localities of northern Greece, during 9 ringing sessions from June 2013 until October 2015. Eighty (11%) of the birds were found to be infested with lice. In 31 different bird species, 560 specimens of lice, belonging to 33 species were recorded. Mixed infestations were recorded in 11 cases where birds were infested with 2-3 different lice species. Four new host-parasite associations were recorded i.e. Menacanthus curuccae from Acrocephalus melanopogon, Menacanthus agilis from Cettia cetti, Myrsidea sp. from Acrocephalus schoenobaenus, and Philopretus citrinellae from Spinus spinus. Moreover, Menacanthus sinuatus was detected on Poecile lugubris, rendering this report the first record of louse infestation in this bird species. The statistical analysis of the data collected showed no association between parasitological parameters (prevalence, mean and median intensity and mean abundance) in two different periods of the year (breeding vs post-breeding season). However, there was a statistically significant difference in the prevalence of infestation between a) migrating and sedentary passerine birds (7.4% vs 13.2%), b) colonial and territorial birds (54.5% vs 9.6%), and c) female and male birds in breeding period (2.6% vs 15.6%).

Size matters for lice on birds: Coevolutionary allometry of host and parasite body size.

Body size is one of the most fundamental characteristics of all organisms. It influences physiology, morphology, behavior, and even interspecific interactions such as those between parasites and their hosts. Host body size influences the magnitude and variability of parasite size according to Harrison's rule (HR: positive relationship between host and parasite body sizes) and Poulin's Increasing Variance Hypothesis (PIVH: positive relationship between host body size and the variability of parasite body size). We analyzed parasite-host body size allometry for 581 species of avian lice (∼15% of known diversity) and their hosts. We applied phylogenetic generalized least squares (PGLS) methods to account for phylogenetic nonindependence controlling for host and parasite phylogenies separately and variance heterogeneity. We tested HR and PIVH for the major families of avian lice (Ricinidae, Menoponidae, Philopteridae), and for distinct ecological guilds within Philopteridae. Our data indicate that most families and guilds of avian lice follow both HR and PIVH; however, ricinids did not follow PIVH and the "body lice" guild of philopterid lice did not follow HR or PIVH. We discuss mathematical and ecological factors that may be responsible for these patterns, and we discuss the potential pervasiveness of these relationships among all parasites on Earth.

Walk or ride? Phoretic behaviour of amblyceran and ischnoceran lice.

Phoresy is a behaviour where one organism hitches a ride on another more mobile organism. This is a common dispersal mechanism amongst relatively immobile species that specialise on patchy resources. Parasites specialise on patchily distributed resources: their hosts. Although host individuals are isolated in space and time, parasites must transmit between hosts or they will die with their hosts. Lice are permanent obligate ectoparasites that complete their entire life cycle on their host. They typically transmit when hosts come into direct contact; however, lice are also capable of transmitting phoretically. Yet, phoresy is rare amongst some groups of lice. Fundamental morphological differences have traditionally been used to explain the phoretic differences amongst different suborders of lice; however, these hypotheses do not fully explain observed patterns. We propose that a more fundamental natural history trait may better explain variation in phoresy. Species able to disperse under their own power should be less likely to engage in phoresy than more immobile species. Here we experimentally tested the relationship between independent louse mobility and phoresy using a system with four species of lice (Phthiraptera: Ischnocera and Amblycera) that all parasitize a single host species, the Rock Pigeon (Columba livia). We quantified the relative ability of all four species of lice to move independently off the host, and we quantified their ability to attach to, and remain attached to, hippoboscid flies (Pseudolynchia canariensis). Our results show that the most mobile louse species is the least phoretic, and the most phoretic species is quite immobile off the host. Our findings were consistent with the hypothesis that phoretic dispersal should be rare amongst species of lice that are capable of independent dispersal; however other factors such as interspecific competition may also play a role.

Epidemiological aspects of lice (Menacanthus species) infections in laying hen flocks from the State of Minas Gerais, Brazil.

The epidemiology of chicken lice species such as Menacanthus stramineus, M. cornutus and M. pallidulus were studied during an observational, analytical and sectional survey, to determine predisposing factors for their occurrence in laying hen farms in the State of Minas Gerais, Brazil. A total of 431 houses on 43 farms were visited in 2012. M. cornutus, M. stramineus and M. pallidulus occurred in 20.9%, 11.6% and 11.6% of farms, respectively. The frequencies of occurrence of M. cornutus, M. stramineus and M.pallidulus in poultry houses were 10.4%, 8.8% and 3.7%, respectively. The epidemiological determinants for the occurrence of these species were investigated using Poisson or logistic regression models. The region of the farm, the recent use of acaricides and the presence of birds, such as saffron finch (Sicalis flaveola), feral pigeon (Columba livia) and Guira cuckoo (Guira guira) around the farms were related to the epidemiology of M. cornutus. Infestation by M. stramineus was associated with age of birds, number of birds per cage and the presence of Guira cuckoo and Chopi blackbird (Gnorimopsar chopi) near the poultry houses. The occurrence of M. pallidulus was influenced by the type of facilities, presence of cattle egret (Bubulcus ibis) and free-range domestic hens around the farm. The use of wire mesh nets in the houses and of forced moulting did not influence lice infestation.

The Chewing Lice (Insecta, Phthiraptera) Fauna of the Swainson's Warbler, Limnothlypis swainsonii (Aves, Parulidae).

We examined Swainson's warblers (Limnothlypis swainsonii (Audubon, 1834), Aves: Parulidae) for lice fauna during 2 yr at three study sites in Arkansas, USA. A total of 66 individuals were examined; eight birds (10.6%) were parasitized with 16 lice of two new species belonging to two genera Myrsidea Waterson, 1915 (Amblycera: Menoponidae) and Brueelia Kéler, 1936 (Ischnocera: Philopteridae). Parasitological parameter data are given on the prevalence of lice on Swainson's warblers. Species descriptions and illustrations are provided for Myrsidea bensoni sp. nov. and Brueelia limnothlypiae sp. nov.; including a key for females of the genus Myrsidea that parasitize Parulidae (Passeriformes).

Host generalists and specialists emerging side by side: an analysis of evolutionary patterns in the cosmopolitan chewing louse genus Menacanthus.

Parasites with wide host spectra provide opportunities to study the ecological parameters of speciation, as well as the process of the evolution of host specificity. The speciose and cosmopolitan louse genus Menacanthus comprises both multi-host and specialised species, allowing exploration of the ecological and historical factors affecting the evolution of parasites using a comparative approach. We used phylogenetic analysis to reconstruct evolutionary relationships in 14 species of Menacanthus based on the sequences of one mitochondrial and one nuclear gene. The results allowed us to validate species identification based on morphology, as well as to explore host distribution by assumed generalist and specialist species. Our analyses confirmed a narrow host use for several species, however in some cases, the supposed host specialists had a wider host spectrum than anticipated. In one case a host generalist (Menacanthus eurysternus) was clustered terminally on a clade almost exclusively containing host specialists. Such a clade topology indicates that the process of host specialisation may not be irreversible in parasite evolution. Finally, we compared patterns of population genetic structure, geographic distribution and host spectra between two selected species, M. eurysternus and Menacanthus camelinus, using haplotype networks. Menacanthus camelinus showed limited geographical distribution in combination with monoxenous host use, whereas M. eurysternus showed a global distribution and lack of host specificity. It is suggested that frequent host switching maintains gene flow between M. eurysternus populations on unrelated hosts in local populations. However, gene flow between geographically distant localities was restricted, suggesting that geography rather than host-specificity is the main factor defining the global genetic diversity of M. eurysternus.

Community of chewing lice (Phthiraptera: Amblycera and Ischnocera) parasites of resident birds at the Archipelago of São Pedro and São Paulo in northeast Brazil.

The current study describes the chewing lice community associated with seabird populations resident at the São Pedro and São Paulo Archipelago in the Atlantic Ocean in Pernambuco State, Brazil. Adults of three species of seabirds were captured using hand-nets for the collection of biometric data and specimens of ectoparasites. In total, 320 birds were examined (120 Sula leucogaster (Boddaert), Brown Booby; 120 Anous stolidus (L.), --Brown Noddy; and 80 Anous minutus Boie, Black Noddy) of which 95% were infested with 8,625 chewing lice, representing eight species of the genera Actornithophilus, Austromenopon, Eidmanniella, Pectinopygus, Quadraceps, and Saemundssonia. On S. leucogaster, Pectinopygus garbei (Pessôa & Guimarães) was more prevalent and had a mean and median intensity of infestation significantly greater than those recorded for Eidmanniella albescens (Piaget). On the two Noddies, the species of Actornithophilus and Quadraceps were significantly more prevalent and abundant than Austromenopon atrofulvum (Piaget) and Saemundssonia remota Timmermann Most of the louse species had a highly aggregated distribution, with k exponent of the negative binomial distribution ranging from 0.04 to 3.06. A weak but significant correlation was found between the abundance of chewing lice and morphometric variables (body weight, wing, beak, tail, and tarsus lengths). It is possible that high rates of infestation have a negative effect on the morphological characteristics of the hosts, including the health of the plumage. All the lice species collected--except for P. garbei (ex S. leucogaster)--were reported for the first time from Brazilian populations of these seabird species.

Chewing lice (Phthiraptera: Amblycera and Ischnocera) from wild birds in southern Vietnam, with descriptions of two new species.

A total of 239 individuals of 50 bird species were examined for chewing lice (Insecta: Phthiraptera) in southern Vietnam. Fifty-six birds of 20 species were parasitised by 15 species of lice belonging to 10 genera from two suborders, Amblycera: Menacanthus, Meromenopon, Myrsidea, and Ischnocera: Alcedoecus, Brueelia, Cuculicola, Meropoecus, Penenirmus, Philopteroides and Philopterus. Thirteen louse samples from Passeriformes were identified to genus only because they contain inadequate material. A total of 29 host-louse associations were found, of which nine are new, including: (1) two new species of the genus Brueelia, which are described and named in this paper: Brueelia binhchauensis from Megalaima lineata (Vieillot, 1816) (Piciformes: Megalaimidae), and Brueelia malacocincla from Malacocincla abbotti Blyth, 1845 (Passeriformes: Pellorneidae); (2) first records of lice from Cyornis hainanus (Ogilvie-Grant, 1900); and (3) the first record of Myrsidea claytoni Hellenthal & Price, 2003 from Cymbirhynchus macrorhynchos (Gmelin, 1788) (Passeriformes: Eurylaimidae), here regarded as a case of natural host-switching. A portion of the mitochondrial cytochrome oxidase I (COI) gene for some species of chewing lice was sequenced in order to assess their genetic divergences.

A survey of ectoparasites infesting urban and rural dogs of Maranhão state, Brazil.

This study evaluated for the first time, ectoparasite infestations on dogs from urban and rural areas of the continental land of the state of Maranhão, northeastern Brazil. In total, 622 dogs were examined for ectoparasite infestations. Overall, 392 (63.0%) were infested with ectoparasites, 154 (51.3%) of 300 urban dogs and 238 (73.9%) of 322 rural dogs. Five species of ectoparasites were found, three ticks [Rhipicephalus sanguineus (Latreille), Amblyomma ovale Koch, and Amblyomma cajennense (F.)], one flea [Ctenocephalides felis (Bouché)], and one louse [(Heterodoxus spininger (Enderlein)]. The frequency of infestation by R. sanguineus tended to be higher in urban than in rural areas, whereas infestations by Amblyomma ticks and C. felis fleas tended to be higher among rural dogs. Louse (H. spininger) infestations were similarly low among all areas. Mixed infestations by at least two species of ectoparasites on the same dog were significantly more frequent on rural than on urban dogs. The most frequent mixed infestation was by R. sanguineus and C. felis, found on 11.4% of the dogs. Further studies are warranted to evaluate canine vector-borne agents in Maranhão, especially because most of the ectoparasites here reported are vectors of major vector-borne diseases, including zoonoses of continental importance.

Chewing lice of genus Myrsidea (Phthiraptera: Menoponidae) from Turdidae (Passeriformes) of Costa Rica, with descriptions of seven new species.

A total of 166 individuals from 10 bird species belonging to the family Turdidae were examined for chewing lice in Costa Rica during 2004, 2009 and 2010. A total of 12 species of the louse genus Myrsidea were collected from 54 birds, including four previously named, seven new undescribed species, and one identified as Myrsidea sp. Names, descriptions and illustrations are given for the seven new species of Myrsidea. They and their type hosts are: Myrsidea assimilis sp. nov. ex Turdus assimilis (Cabanis, 1850), M. cerrodelamuertensis sp. nov. ex Catharus gracilirostris (Salvin, 1865). M. hrabaki sp. nov. ex Myadestes melanops (Salvin, 1865), M. obsoleti sp. nov. ex Turdus obsoletus (Lawrence, 1862), M. quinchoi sp. nov. ex Catharus frantzii (Cabanis, 1861), M. tapanti sp. nov. ex Catharus fuscater (Lafresnaye, 1845), and M. tapetapersi sp. nov. ex Turdus nigrescens (Cabanis, 1861). Records of four named and one unidentified species of Myrsidea from other Costa Rican thrushes are also given and discussed.

Egg laying site and oviposition pattern of two Phthirapteran species parasitizing red whiskered Bulbul (Pycnonotus jocosus).

OBJECTIVE: Present study was performed to record the oviposition and egg laying pattern of two phthirapteran species infesting red whiskered Bulbul. METHODS: The number of egg laid by each species on different parts of body was recorded by direct observation under stereozoom binocular microscope. Feathers bearing egg were subjected to SEM to observe the pattern of egg laying. RESULTS: The maximum percentage of egg of the ischnoceran louse, Brueelia guldum were recorded on feather of back region, followed by neck and breast. The amblyceran louse, Menacanthus eurysternus prefers to lay eggs mainly on neck, head and nape feathers. CONCLUSION: The ischnoceran louse, Brueelia guldum exhibits widespread oviposition sites while amblyceran louse, Menacanthus eurysternus shows restricted oviposition sites on the host body.

Housing and dustbathing effects on northern fowl mites (Ornithonyssus sylviarum) and chicken body lice (Menacanthus stramineus) on hens.

Hen housing (cage or cage-free) did not impact overall abundances of northern fowl mites, Ornithonyssus sylviarum (Canestrini & Fanzago) (Acari: Macronyssidae), or chicken body lice, Menacanthus stramineus (Nitzsch) (Phthiraptera: Menoponidae). Cage-free hens received a dustbox with sand plus diatomaceous earth (DE), kaolin clay or sulphur. Weekly use varied from none to 100% of hens; 73% of hens used the dustbox at least once. Ectoparasite populations on dustbathing hens (users) were compared with those on non-user cage-free and caged hens. All materials reduced ectoparasites on user hens by 80-100% after 1 week of dustbox use. Diatomaceous earth and kaolin failed to reduce ectoparasites on non-user hens, and ectoparasites on user hens recovered after dustbox removal. A sulphur dustbox eliminated mites from all hens (including non-users) within 2-4 weeks. Residual sulphur controlled mites until the end of the experiment (up to 9 weeks), even after the dustbox was removed. Louse populations on hens using the sulphur dustbox were reduced in 1-2 weeks. Residual sulphur effects were less evident in lice, but the use of a sulphur dustbox by a higher proportion of hens extended louse control to all hens. This is the first experimental study to show that bird dustbathing in naturally and widely available dust materials (particularly kaolin) can suppress ectoparasites and thus the behaviour is probably adaptive.