First record of Cebidicola armatus (Phthiraptera: Trichodectidae) on the Brachyteles hypoxanthus (Primate: Atelidae) in Brazil.

This study reports for the first time the infestation of Cebidicola armatus in Brachyteles hypoxanthus. In total, 14 lice were recovered of an individual in Minas Gerais, Brazil. These were subjected to a microscopic analysis and the identification of C. armatus was carried out through its very characteristic morphology.

Eutrichophilus cordiceps Mjöberg, 1910 (Ischnocera: Trichodectidae) in Spiny Tree Porcupines (Coendou villosus): New locality records and the first molecular evidence of association with Bartonella sp.

The chewing louse genus Eutrichophilus Mjöberg has 19 species only associated with porcupines (Rodentia: Erethizontidae). Of these species, E. cercolabes, E. cordiceps, E. emersoni, E. minor, E. moojeni, and E. paraguayensis have been recorded in Brazil. In the present study, we report E. cordiceps for the first time in the São Paulo State (Bauru Municipality) and for the second time in the Santa Catarina State (Lages Municipality), providing scanning electron images and light microscopy for the eggs, as well as the first molecular data (18S rRNA) for the genus. Additionally, Bartonella sp. was detected for the first time in this chewing lice species.

Parasitic findings on threatened pudu deer from Central Chile accounts first genetic characterization of lice parasitizing P. puda in Chile and the first molecular report of Taenia hydatigena metacestodes in this species.

Southern pudu (Pudu puda) is a threatened endemic deer of the temperate forests of Chile. In recent years pudu populations rates have decreased mainly due to anthropogenic causes including forest loss and landscape fragmentation. In this context, the parasitic fauna of Chilean pudu has been scarcely investigated. The aim of this study was to determine the parasitic status of rescued pudu n = 13 from its natural habitat in Central Chile (Maule region) during March 2022 and June 2023 by applying morphological, histopathological, and molecular analyses. As result, we report the presence of transmission of parasites from dogs to pudus as showed by the presence of metacestodes of the parasite Taenia hydatigena on omentum, liver, and pleura of pudus during postmortem examinations, being the first molecular report on the presence of this parasite on Chilean pudu. Meanwhile, ectoparasite examinations determined the presence of chewing and sucking lice on pudu exemplars here analysed. Molecular and phylogenetic analysis of lice revealed new insights on Bovicola and Anoplura lice parasitizing P. puda in Chile, equally being the first genetic characterization of lice parasitizing pudu exemplars in Chile. In addition, parasite loads of lice and metacestodes were analysed. However, no statistically significance was observed when comparing environmental and individual traits influence on parasite load variation. Overall, the study area is the northern limit of habitat distribution of this specie in Chile and we here provide novel information on pudu deer parasites, thus making a useful and valuable contribution to the parasitological knowledge on this threatened species.

Co-infestation caused by Goniodes pavonis (L., 1758) (Ischnocera: Goniodidae) and Goniocotes rectangulatus Nitzsch [In Giebel], 1866 on white Indian peafowl, Pavo cristatus L., 1758 (Galliformes: Phasianidaede) in Brazil.

The genus Goniodes Nitzsch and Goniocotes Burmeister (Ischnocera: Goniogodidae) are distributed worldwide, and exclusively parasitizing avian hosts of the Galliformes. In Brazil, there are only four species recorded: Goniodes dissimilis Denny, Goniodes gigas (Taschenberg), Goniodes pavonis (L.), and Goniocotes gallinae (DeGeer). In the present study, we are reporting the co-parasitism of G. pavonis and G. rectangulatus Nitzsch [In Giebel] on specimens of the white Pavo cristatus, popularly known as 'white Indian peafowl' for the first time. Furthermore, a new Brazilian locality for G. pavonis species has been reported, as well as the first time that G. rectangulatus is reported to Brazil. Additionally, we provide the first molecular information for G. pavonis.

Co-infestation caused by Goniodes pavonis (L., 1758) (Ischnocera: Goniodidae) and Goniocotes rectangulatus Nitzsch [In Giebel], 1866 on white Indian peafowl, Pavo cristatus L., 1758 (Galliformes: Phasianidaede) in Brazil

The genus Goniodes Nitzsch and Goniocotes Burmeister (Ischnocera: Goniogodidae) are distributed worldwide, and exclusively parasitizing avian hosts of the Galliformes. In Brazil, there are only four species recorded: Goniodes dissimilis Denny, Goniodes gigas (Taschenberg), Goniodes pavonis (L.), and Goniocotes gallinae (DeGeer). In the present study, we are reporting the co-parasitism of G. pavonis and G. rectangulatus Nitzsch [In Giebel] on specimens of the white Pavo cristatus, popularly known as ‘white Indian peafowl’ for the first time. Furthermore, a new Brazilian locality for G. pavonis species has been reported, as well as the first time that G. rectangulatus is reported to Brazil. Additionally, we provide the first molecular information for G. pavonis.

Contribution to the knowledge of Neotrichodectes (Nasuicola) pallidus (Piaget, 1880) (Phthiraptera: Trichodectidae).

The species in the genus Neotrichodectes (Phthiraptera: Ischnocera) infest carnivores. Neotrichodectes (Nasuicola) pallidus (Piaget, 1880), which has been primarily found parasitizing Procyonidae mammals, has been recorded in ring-tailed coatis (Nasua nasua) in the Brazilian states of Minas Gerais, Pernambuco, Santa Catarina, Rio Grande do Sul and Pernambuco. We report a new record of N. pallidus in coatis in the state of Mato Grosso do Sul, central-western Brazil, using morphological (Light and Scanning Electronic Microscopy) and molecular approaches (PCR, sequencing and phylogenetic analysis). Coatis were sampled in two peri-urban areas of Campo Grande city, Mato Grosso do Sul state, Brazil, between March 2018 and March 2019, as well as in November 2021. Lice were collected and examined under light and Scanning Electron Microscopy. DNA was also extracted from nymphs and adults and submitted to PCR assays based on the 18S rRNA and cox-1 genes for molecular characterization. One hundred and one coatis were sampled from 2018 to 2019 and 20 coatis in 2021 [when the intensity of infestation (II) was not accessed]. Twenty-six coatis (26/101-25.7%) were infested with at least one louse, with a total of 59 lice collected in 2018-2019. The II ranged from one to seven lice (mean 2.2 ± SD 1.7). The louse species was confirmed based on the following morphological characteristics: female gonapophyses rounded with the setae along anterior region but not in the medial margin; the male genitalia with a parameral arch not extending beyond the endometrial plate. The same ornamentation was observed on the abdomen of the females, males, and nymphs. The nymphs and the eggs were described in detail for the first time. The obtained 18S rRNA and cox1 sequences from N. pallidus clustered in a clade with other sequences of Ischnocera species. In the present study, a new record of the louse N. pallidus in central-western Brazil was provided, along with new insights into the morphological features of this species, with the first morphology contribution of nymphal and eggs stages.

Chewing lice of Procellaria aequinoctialis Linnaeus, 1758 in Brazil with a new host record.

The white-chinned petrel (Procellaria aequinoctialis) is a seabird widely distributed in the circumpolar sub-Antarctic islands and subtropical regions, including Brazilian waters. Among the parasites present on the white-chinned petrel are the chewing lice. This seabird is parasitized by 4 known lice species to date. In this study we evaluated the ectoparasites of 2 white-chinned petrels rescued by an animal rehabilitation center in Rio de Janeiro, Brazil and recorded 4 species of chewing lice, of which 3 are already known for this host. One of the species however, has never been recorded in Brazil and another one has never been recorded parasitizing P. aequinoctialis, making this a new host record.

New records of chewing lice (Insecta: Phthiraptera) parasites of Brazilian Anhimidae, Threskiornithidae, and Aramidae (Aves)

We present records of chewing lice collected from bird skins of the families Anhimidae, Threskiornithidae, and Aramidae deposited at the Museum of Zoology of University of São Paulo (MZUSP). Twenty-one chewing lice species from the suborders Amblycera and Ischnocera were identified, seven of which are new records for Brazil. These species belong to the genera Ardeicola (1), Colpocephalum (3), Ibidoecus (1), and Plegadiphilus (2). Furthermore, ten species were recorded from new localities in Brazil, and Colpocephalum cayennensisPrice & Emerson, 1967 is for the first time recorded with precise locality in the country. Lastly, the bird host subspecies Phimosus infuscatus nudifrons (Spix, 1825) (Threskiornithidae) was for the first time found to harbor lice species.

Contribution to the knowledge of Neotrichodectes (Nasuicola) pallidus (Piaget, 1880) (Phthiraptera: Trichodectidae)

The species in the genus Neotrichodectes (Phthiraptera: Ischnocera) infest carnivores. Neotrichodectes (Nasuicola) pallidus (Piaget, 1880), which has been primarily found parasitizing Procyonidae mammals, has been recorded in ring-tailed coatis (Nasua nasua) in the Brazilian states of Minas Gerais, Pernambuco, Santa Catarina, Rio Grande do Sul and Pernambuco. We report a new record of N. pallidus in coatis in the state of Mato Grosso do Sul, central-western Brazil, using morphological (Light and Scanning Electronic Microscopy) and molecular approaches (PCR, sequencing and phylogenetic analysis). Coatis were sampled in two peri-urban areas of Campo Grande city, Mato Grosso do Sul state, Brazil, between March 2018 and March 2019, as well as in November 2021. Lice were collected and examined under light and Scanning Electron Microscopy. DNA was also extracted from nymphs and adults and submitted to PCR assays based on the 18S rRNA and cox-1 genes for molecular characterization. One hundred and one coatis were sampled from 2018 to 2019 and 20 coatis in 2021 [when the intensity of infestation (II) was not accessed]. Twenty-six coatis (26/101–25.7%) were infested with at least one louse, with a total of 59 lice collected in 2018–2019. The II ranged from one to seven lice (mean 2.2 ± SD 1.7). The louse species was confirmed based on the following morphological characteristics: female gonapophyses rounded with the setae along anterior region but not in the medial margin; the male genitalia with a parameral arch not extending beyond the endometrial plate. The same ornamentation was observed on the abdomen of the females, males, and nymphs. The nymphs and the eggs were described in detail for the first time. The obtained 18S rRNA and cox1 sequences from N. pallidus clustered in a clade with other sequences of Ischnocera species. In the present study, a new record of the louse N. pallidus in central-western Brazil was provided, along with new insights into the morphological features of this species, with the first morphology contribution of nymphal and eggs stages.

The Attractivity of the Head Louse, Pediculus humanus capitis (Pediculidae: Anoplura) to Isolated Compounds and Blends of Human Skin.

Human head lice Pediculus humanus capitis De Geer (Phthiraptera: Pediculidae) are ectoparasites that cause pediculosis, a global scale disease mainly found in school-age children. Previous works from our laboratory found nonanal, sulcatone, and geranylacetone as the main human scalp volatile components, and individually evaluated their attraction to head lice using an olfactometer. In this work, we compared how their blends at different concentrations attract head lice, and how their blended effect compares to the effect of isolated compounds. At the concentrations evaluated, individual components did not show attraction towards head lice, but a ternary mixture of them was attractive. Moreover, a solvent extract from the human head scalp was analyzed by GC-MS, finding that tetradecanoic acid, palmitic acid, oleic acid, palmitoleic acid, and squalene are the most abundant components. Attraction to these individual compounds at natural concentrations was tested by bioassays in a circular experimental arena. No attraction was observed when the components were tested individually, but when they were evaluated as a blend they attracted head lice. This work presents new information about how chemical signals are attractive at certain concentrations and proportions. This information could be used to better understand communication mechanisms in head lice and for the development of louse repellents.

Eficácia do caldo de fumo (Nicotiana tabacum) no controle do Menacanthus stramineus (phthiraptera: menoponidae) em galinhas poedeiras no município de salinas, Minas Gerais / Efficacy of tobacco broth (Nicotiana tabacum) in the control of Menacanthus stramineus (phthiraptera: menoponidae) in laying hens in the municipality of salinas, Minas Gerais / Eficacia del caldo ahumado (Nicotiana tabacum) en el control de Menacanthus stramineus (phthiraptera: menoponidae) en gallinas ponedoras del municipio de salinas, Minas Gerais

Em granjas de postura, infestações por ectoparasitas são um problema que gera gastos e diminui a produção dos animais, pelo aumento do estresse. O piolho Menacanthus stramineus é apontado como um dos principais parasitas na avicultura comercial. Há um interesse crescente no uso de abordagens de controle de parasitos na produção de aves minimizando o uso de pesticidas sintéticos tradicionais. Objetivou-se avaliar a eficácia do caldo de fumo (Nicotiana tabacum) no controle do Menacanthus stramineus (Phthiraptera: Menoponidae) em galinhas poedeiras no município de Salinas, Minas Gerais. Para isso, 30 galinhas poedeiras naturalmente infestadas por piolhos, oriundas dos Setor de Zootecnia I do Instituto Federal do Norte de Minas Gerais - Campus Salinas (IFNMG), foram selecionadas aleatoriamente e divididas em três grupos, mantidos em galpões distintos e separados: Grupo I- Tratado com caldo de fumo, conforme Sagrilo e colaboradores (2007); Grupo II- Tratado com Colosso Pulverização®, diluídos 11ml em nove litros; Grupo III- Controle, tratado com água, sendo todos os grupos submetidos ao tratamento por imersão em balde com nove litros de solução. Espécimes de piolhos foram coletados manualmente através de inspeção visual, juntamente com penas contendo ovos em sua base e encaminhados ao Laboratório de Parasitologia Veterinária (LPV) do IFNMG, para realização do diagnóstico parasitológico através de chaves de identificação. Os espécimes foram clarificados em hidróxido de potássio a 10% e observados em microscopia óptica nas objetivas de 4x e 10x. Os ovos foram observados em microscópio estereoscópico, no aumento de 4x. Todas as galinhas foram diagnosticadas com infestação por ovos e adultos de M. stramineus. Para o banho de imersão, as aves foram seguradas pelo pescoço e pelas asas, mergulhando todo seu corpo em balde plástico. Sete dias após a realização dos tratamentos, as aves foram novamente examinadas em uma inspeção visual pelos mesmos examinadores. O Grupo I não apresentou ovos e nem adultos de M. stramineus em nenhuma ave, revelando 100% de eficácia. O Grupo II não apresentou adultos, mas foram observados ovos aderidos à base das penas, friáveis ao toque, em nove aves. Posteriormente, verificou-se que se tratava de cascas de ovos vazias. E, o Grupo III estava ainda intensamente parasitado por ovos e adultos de M. stramineus. Conclui-se que o caldo de fumo (Nicotiana tabacum) preparado conforme descrito na metodologia do presente trabalho, é eficaz no controle do piolho Menacanthus stramineus (Phthiraptera: Menoponidae) em galinhas poedeiras no município de Salinas, Minas Gerais.(AU)

In laying hens barns, ectoparasite infestations are a problem that generates expenses and decreases animal production due to increased stress. The Menacanthus stramineus louse is considered one of the main parasites in commercial poultry. There is growing interest in the use of parasite control approaches in poultry production while minimizing the use of traditional synthetic pesticides. The objective of this study was to evaluate the efficacy of tobacco broth (Nicotiana tabacum) in controlling Menacanthus stramineus (Phthiraptera: Menoponidae) in laying hens in the municipality of Salinas, Minas Gerais. Thus, 30 laying hens naturally infested with lice, housed at the Zootechnics Sector I at the Federal Institute of Northern Minas Gerais ­ Campus Salinas (FINMG) were randomly selected and divided into three groups, which were kept in different and separated barns: Group I- Treated with tobacco broth, according to Sagrilo et al (2007); Group II- Treated with Colosso Pulverização®, diluted 11ml in nine liters; Group III- Control, treated with water. All groups were elaborated for treatment by immersion in a bucket with nine liters of solution. Lice specimens were manually collected through visual inspection including feathers containing eggs at their base and then sent to the Veterinary Parasitology Laboratory (VPL) at the FINMG for parasitological diagnosis by using identification keys. The specimens were clarified in potassium hydroxide 10% and observed under optical microscopy at 4x and 10x objectives. The eggs were observed under a stereoscopic microscope at 4x magnification. All chickens were diagnosed with infestation of adult and egg stages of M. stramineus. For the immersion bath, the animals were held by the neck and wings, dipping their entire bodies in a plastic bucket. Seven days after the treatments were carried out they were again examined in a visual inspection by the same examiners. Group I did not show any eggs or adults of M. stramineus, which presented efficacy of 100%. Group II did not have adults, but friable eggs when touched adhered to the base of the feathers were observed in nine animals. Later on, it was found that they were empty egg shells. And, Group III was still intensely parasitized by eggs and adults stages of M. stramineus. It is concluded that tabocco broth (Nicotiana tabacum) prepared as described in the methodology of the present study is effective in controlling the lice Menacanthus stramineus (Phthiraptera: Menoponidae) in laying hens in the municipality of Salinas, Minas Gerais.(AU)

En las gallinas ponedoras, las infestaciones de ectoparásitos son un problema que genera gastos y disminuye la producción animal, debido al aumento del estrés. El piojo Menacanthus stramineus se considera uno de los principales parásitos de las aves comerciales. Existe un interés creciente en el uso de enfoques de control de parásitos en la producción avícola mientras se minimiza el uso de pesticidas sintéticos tradicionales. El objetivo fue evaluar la eficacia del caldo de tabaco (Nicotiana tabacum) en el control de Menacanthus stramineus (Phthiraptera: Menoponidae) en gallinas ponedoras del municipio de Salinas, Minas Gerais. Para ello, 30 gallinas ponedoras naturalmente infestadas de piojos, del Sector I de Zootecnia del Instituto Federal del Norte de Minas Gerais - Campus Salinas (IFNMG), fueron seleccionadas al azar y divididas en tres grupos, mantenidos en galpones separados y separados: Grupo I - Tratado con caldo de humo, según Sagrilo et al. (2007); Grupo II- Tratado con Colosso Pulverização®, diluido 11ml en nueve litros; Grupo III- Control, tratado con agua, con todos los grupos sometidos a tratamiento por inmersión en un balde con nueve litros de solución. Las muestras de piojos se recolectaron manualmente mediante inspección visual, junto con plumas que contenían huevos en su base y se enviaron al Laboratorio de Parasitología Veterinaria (LPV) del IFNMG, para el diagnóstico parasitológico mediante claves de identificación. Las muestras se clarificaron en hidróxido de potasio al 10% y se observaron bajo microscopía óptica en objetivos 4x y 10x. Los huevos se observaron bajo un microscopio estereoscópico, con un aumento de 4x. Todos los pollos fueron diagnosticados con huevos de M. stramineus e infestación de adultos. Para el baño de inmersión, se sujetó a las aves por el cuello y las alas, sumergiendo todo su cuerpo en un balde de plástico. Siete días después de que se llevaron a cabo los tratamientos, las aves fueron examinadas de nuevo en una inspección visual por los mismos examinadores. El grupo I no presentó huevos ni adultos de M. stramineus en ninguna ave, mostrando una efectividad del 100%. El grupo II no presentó adultos, pero se observaron huevos adheridos a la base de las plumas, friables al tacto, en nueve aves. Posteriormente, se encontró que se trataba de cáscaras de huevo vacías. Y, el Grupo III todavía estaba intensamente parasitado por huevos y adultos de M. stramineus. Se concluye que el caldo de tabaco (Nicotiana tabacum) elaborado según lo descrito en la metodología del presente trabajo, es efectivo en el control de los piojos Menacanthus stramineus (Phthiraptera: Menoponidae) en gallinas ponedoras del municipio de Salinas, Minas Gerais.(AU)

Sensory features of the human louse antenna: new contributions and comparisons between ecotypes.

Body and head lice are known to be exclusive ectoparasites of human hosts. Current genomic and transcriptomic data suggest that both louse types represent ecotypes of the same species. They exhibit morphological and physiological differences that probably arose from living in different biotopes. Sensory traits represent suitable candidates to be affected by environmental heterogeneity. Therefore, through scanning electron microscope studies, this study analysed and compared the sensory structures of both ecotypes' antennae. Seven types of sensory structures were identified in both ecotypes: bristles, tuft organs, pore organs, single pore and three morphotypes of sensilla basiconica. Notably, the single pore and the morphotypes of sensilla basiconica were described for the first time in the body louse antenna. This study's comparative analysis mainly revealed size differences across the sensory structures of the ecotypes. Bristles of the flagellomere 2 of the body louse antenna were longer than the head louse bristles. In addition, the pore organs of the head louse antenna presented a higher diameter than those of the body louse. The possible relevance of size differences regarding the biotopes exploited by the body louse and the head louse is discussed. Yet, physiological studies may help to fully understand the phenotypical differences of both ecotypes.

Occurrence of the louse fly Ornithoctona erythrocephala Leach (1817) (Diptera: Hippoboscidae) on a free-living red-legged seriema (Cariama cristata) / Ocorrência da mosca Ornithoctona erythrocephala Leach, 1817 (Diptera: Hippoboscidae) em seriema (Cariama cristata) de vida livre

Abstract The aim of this study was to report, for the first time, the occurrence of the hippoboscid fly Ornithoctona erythrocephala on a red-legged seriema (Cariama cristata). A Diptera specimen was found among the feathers of a free-living red-legged seriema, which was referred to necropsy at the Wild Animal Pathology Service, UNESP Jaboticabal. The fly was collected, stored in absolute alcohol, and shipped to the Institute of Biosciences of the Federal University of Mato Grosso do Sul for proper identification. Based on morphological characters, the specimen was identified as a female of Ornithoctona erythrocephala. This study provides a report on a new host for O. erythrocephala.

Resumo O objetivo deste estudo foi descrever pela primeira vez a ocorrência da mosca Hippoboscidae Ornithoctona erythrocephala em uma seriema (Cariama cristata). Um espécime de díptero foi encontrado entre as penas de dessa ave, que havia sido encaminhada para necropsia ao Serviço de Patologia de Animais Selvagens, UNESP, Jaboticabal. A mosca foi armazenada em álcool absoluto e enviada ao Instituto de Biociências da Universidade Federal do Mato Grosso do Sul para identificação por um especialista. Baseado em características morfológicas, o espécime foi identificado como fêmea de Ornithoctona erythrocephala. Este relato oferece a descrição de um novo hospedeiro para O. erythrocephala.

Island and Riverine populations of Alouatta belzebul from the Brazilian Amazon parasitized by Pediculus mjobergi.

Mammalian lice are obligate hematophagous ectoparasites that remain on the host throughout the life cycle. This study showed an endangered wild howler species (Alouatta belzebul) parasitized by Pediculus mjobergi. Twenty-seven primates were rescued during wildlife rescue activities in the process of vegetation suppression at the Belo Monte Hydroelectric Power Plant (UHE), located on the lower Xingu River, in the Brazilian Amazon basin. Among the 27 primates examined from two vegetal formations (alluvial rainforest and liana-infested forest) areas, 13 (48.15%) were parasitized by lice with all positive primates being from alluvial rainforest. Optical and scanning electron microscopy allowed the visualization of the structures and the diagnostic characters of the lice species in greater detail expanding the current description. These results highlight the importance of considering ecological and regional features to provide a better understanding of the factors that promote parasitism.

Integrative taxonomic description of the chewing louse Tricholipeurus lipeuroides infesting Odocoileus virginianus veraecrucis white-tailed deer in Veracruz, Mexico.

Chewing lice (Phthiraptera: Amblycera, Ischnocera) represent a component of the ectoparasite fauna associated with large sized mammals as deers. However, the diversity of chewing louse species infesting deer remains to be fully characterized in the Neotropics. Little is known about the chewing lice infesting the extant fourteen subspecies of white-tailed deer (Odocoileus virginianus) in Mexico. Known to infest white-tailed deer (WTD) in Canada and the United States (U.S.), Tricholipeurus lipeuroides is a chewing louse species that was originally described in the nineteenth century infesting O. v. mexicanus in Mexico. For the first time, infestation of O. v. veraecrucis, a Neotropical WTD subspecies in Mexico, with T. lipeuroides is reported herein. An integrative taxonomic approach was taken by combining morphological and molecular analyses to describe the T. lipeuroides infestion of O. v. veraecrucis. Ecological parameters of the T. lipeuroides infestations were also calculated. The prevalence was 91.7% of the 56 O. v. veraecrucis (29 females and 27 males) inspected while under chemical restraint that were sampled at 3 sites in the central region of Veracruz state in Mexico. The amplification and sequencing of previously reported T. lipeuroides Cytochrome Oxidase Subunit I gene confirmed the identity of all the chewing louse life stages. These results are discussed in the context of comparative analyses on the emergence of novel chewing lice-deer associations.

Tackling the Molecular Drug Sensitivity in the Sea Louse Caligus rogercresseyi Based on mRNA and lncRNA Interactions.

Caligus rogercresseyi, commonly known as sea louse, is an ectoparasite copepod that impacts the salmon aquaculture in Chile, causing losses of hundreds of million dollars per year. This pathogen is mainly controlled by immersion baths with delousing drugs, which can lead to resistant traits selection in lice populations. Bioassays are commonly used to assess louse drug sensitivity, but the current procedures may mask relevant molecular responses. This study aimed to discover novel coding genes and non-coding RNAs that could evidence drug sensitivity at the genomic level. Sea lice samples from populations with contrasting sensitivity to delousing drugs were collected. Bioassays using azamethiphos, cypermethrin, and deltamethrin drugs were conducted to evaluate the sensitivity and to collect samples for RNA-sequencing. Transcriptome sequencing was conducted on samples exposed to each drug to evaluate the presence of coding and non-coding RNAs associated with the response of these compounds. The results revealed specific transcriptome patterns in lice exposed to azamethiphos, deltamethrin, and cypermethrin drugs. Enrichment analyses of Gene Ontology terms showed specific biological processes and molecular functions associated with each delousing drug analyzed. Furthermore, novel long non-coding RNAs (lncRNAs) were identified in C. rogercresseyi and tightly linked to differentially expressed coding genes. A significant correlation between gene transcription patterns and phenotypic effects was found in lice collected from different salmon farms with contrasting drug treatment efficacies. The significant correlation among gene transcription patterns with the historical background of drug sensitivity suggests novel molecular mechanisms of pharmacological resistance in lice populations.

The Sensory Machinery of the Head Louse Pediculus humanus capitis: From the Antennae to the Brain.

Insect antennae are sophisticated sensory organs, usually covered with sensory structures responsible for the detection of relevant signals of different modalities coming from the environment. Despite the relevance of the head louse Pediculus humanus capitis as a human parasite, the role of its antennal sensory system in the highly dependent relation established with their hosts has been barely studied. In this work, we present a functional description of the antennae of these hematophagous insects by applying different approaches, including scanning electron microscopy (SEM), anterograde antennal fluorescent backfills, and behavioral experiments with intact or differentially antennectomized lice. Results constitute a first approach to identify and describe the head louse antennal sensilla and to determine the role of the antenna in host recognition. SEM images allowed us to identify a total of 35-40 sensilla belonging to seven different morphological types that according to their external architecture are candidates to bear mechano-, thermo-, hygro-, or chemo-receptor functions. The anterograde backfills revealed a direct neural pathway to the ipsilateral antennal lobe, which includes 8-10 glomerular-like diffuse structures. In the two-choice behavioral experiments, intact lice chose scalp chemicals and warm surfaces (i.e., 32°C) and avoided wet substrates. Behavioral preferences disappeared after ablation of the different flagellomeres of their antenna, allowing us to discuss about the location and function of the different identified sensilla. This is the first study that integrates morphological and behavioral aspects of the sensory machinery of head lice involved in host perception.

Tifus / Typhus

Resumen El género Rickettsia está compuesto por dos grupos definidos antigenicamente: el grupo tifus, que incluye a Rickettsiaprowazekii, causante del tifus epidémico o exantemático, y a R. typhi, causante del tifus murino o endémico; el otro grupo es el de las fiebres manchadas. El género Rickettsia está constituido por diferentes especies de bacterias gramnegativas; a su vez, forma parte de la familia Rickettsiaceae (junto a Coxiella, Ehrlichia y Bartonella). Todas las especies del género tienen en común ser parásitos intracelulares estrictos con tamaño promedio de 0.3 a 0.5 pm, además de que requieren ciertos vectores que permitan su trasmisión y es difícil cultivarlas en el laboratorio. Este artículo revisa las variedades de manifestación del tifus y su situación en México.

Abstract The genus Rickettsia is composed of two groups antigenically defined, typhus group including Rickettsia prowazekii, which causes epidemic typhus and R. typhi, which causes murine or endemic typhus. The other group is one of spotted fever. The genus Rickettsia is made up of different species of gramnegative bacteria, in turn it is part of the family Rickettsiaceae (with Coxiella, Ehrlichia, and Bartonella). All species of the genus have in common being strict intracellular parasites with an average size of 0.3 to 0.5 pm, require certain vectors that allow trasmission, and have great difficulty be grown in the laboratory. Below there is a review of the varieties of presentation of typhus and its situation in Mexico.

Chewing lice (Insecta, Phthiraptera) of the fulvous whistling duck Dendrocygna bicolor (Vieillot, 1816) and white-faced whistling-duck Dendrocygna viduata (Linnaeus, 1766) from Rio Grande do Sul Southern Brazil / Malófagos (Insecta, Phthiraptera) de marreca caneleira Dendrocygna bicolor (Vieillot, 1816) e marreca piadeira Dendrocygna viduata (Linnaeus, 1766) na região sul do Rio Grande do Sul

The authors report the occurrence of Acidoproctus rostratus (Rudow, 1866), Holomenopon leucoxanthum (Burmeister, 1838), Trinoton aculeatum (Piaget, 1885), Trinoton querquedulae (Linnaeus, 1758) and Anatoecus dentatus (Scopoli, 1763) in Dendrocygna bicolor (Vieillot, 1816) and Dendrocygna viduata (Linnaeus, 1766); Anatoecus icterodes (Nitzsch, 1818) in D. bicolor and Anaticola chaetodens (Eichler, 1954) in D. viduata. Significant differences in the prevalence were found between T. aculeatum and T. querquedulae in D. bicolor as well as D. viduata, which is characterized as a potential event of colonization. Significant differences were also found for the prevalence and mean abundance of Anatoecus spp. between D. bicolor and D. viduata. The occurrence of Trinoton querquedulae in D. bicolor and D. viduata, of Anatoecus dentatus in D. bicolor and Anaticola chaetodens in D. viduata characterize new hosts species to these species of lice.(AU)

Os autores relatam a ocorrência de Acidoproctus rostratus (Rudow, 1866), Holomenopon leucoxanthum (Burmeister, 1838), Trinoton aculeatum (Piaget, 1885), Trinoton querquedulae (Linnaeus, 1758) e Anatoecus dentatus (Scopoli, 1763) em Dendrocygna bicolor (Vieillot, 1816) e Dendrocygna viduata (Linnaeus, 1766); Anatoecus icterodes (Nitzsch, 1818) em D. bicolor e Anaticola chaetodens (Eichler, 1954) em D. viduata. Diferenças significativas na prevalência foram encontradas entre T. aculeatum e T. querquedulae, tanto em D. bicolor quanto em D. viduata, sendo esse achado caracterizado como um evento potencial de colonização. Outras diferenças também foram encontradas para a prevalência e a abundância média de Anatoecus spp. entre D. bicolor e D. viduata. A ocorrência de Trinoton querquedulae em D. bicolor e D. viduata, de Anatoecus dentatus em D. bicolor e de Anaticola chaetodens em D. viduata, caracteriza novos hospedeiros para essas espécies de piolhos.(AU)

Chewing lice (Insecta, Phthiraptera) of the fulvous whistling duck Dendrocygna bicolor (Vieillot, 1816) and white-faced whistling-duck Dendrocygna viduata (Linnaeus, 1766) from Rio Grande do Sul Southern Brazil / Malófagos (Insecta, Phthiraptera) de marreca caneleira Dendrocygna bicolor (Vieillot, 1816) e marreca piadeira Dendrocygna viduata (Linnaeus, 1766) na região sul do Rio Grande do Sul

The authors report the occurrence of Acidoproctus rostratus (Rudow, 1866), Holomenopon leucoxanthum (Burmeister, 1838), Trinoton aculeatum (Piaget, 1885), Trinoton querquedulae (Linnaeus, 1758) and Anatoecus dentatus (Scopoli, 1763) in Dendrocygna bicolor (Vieillot, 1816) and Dendrocygna viduata (Linnaeus, 1766); Anatoecus icterodes (Nitzsch, 1818) in D. bicolor and Anaticola chaetodens (Eichler, 1954) in D. viduata. Significant differences in the prevalence were found between T. aculeatum and T. querquedulae in D. bicolor as well as D. viduata, which is characterized as a potential event of colonization. Significant differences were also found for the prevalence and mean abundance of Anatoecus spp. between D. bicolor and D. viduata. The occurrence of Trinoton querquedulae in D. bicolor and D. viduata, of Anatoecus dentatus in D. bicolor and Anaticola chaetodens in D. viduata characterize new hosts species to these species of lice.

Os autores relatam a ocorrência de Acidoproctus rostratus (Rudow, 1866), Holomenopon leucoxanthum (Burmeister, 1838), Trinoton aculeatum (Piaget, 1885), Trinoton querquedulae (Linnaeus, 1758) e Anatoecus dentatus (Scopoli, 1763) em Dendrocygna bicolor (Vieillot, 1816) e Dendrocygna viduata (Linnaeus, 1766); Anatoecus icterodes (Nitzsch, 1818) em D. bicolor e Anaticola chaetodens (Eichler, 1954) em D. viduata. Diferenças significativas na prevalência foram encontradas entre T. aculeatum e T. querquedulae, tanto em D. bicolor quanto em D. viduata, sendo esse achado caracterizado como um evento potencial de colonização. Outras diferenças também foram encontradas para a prevalência e a abundância média de Anatoecus spp. entre D. bicolor e D. viduata. A ocorrência de Trinoton querquedulae em D. bicolor e D. viduata, de Anatoecus dentatus em D. bicolor e de Anaticola chaetodens em D. viduata, caracteriza novos hospedeiros para essas espécies de piolhos.