RESUMEN
Birds have a diverse community of "permanent" arthropods that complete their entire life cycle on the body of the host. Because some of these arthropods are parasites that reduce host fitness, birds control them by grooming, which consists of preening with the beak and scratching with the feet. Although preening is the primary component of grooming, scratching is essential for controlling arthropods on the head and neck, which cannot be preened. Several unrelated groups of birds have evolved comb-like pectinate claws on the middle toenail of each foot. We tested the role of these claws in the control of arthropods by experimentally removing teeth from the claws of captive western cattle egrets (Bubulcus ibis) infested with chewing lice (Insecta: Phthiraptera), feather mites (Acari: Sarcoptiformes), and nasal mites (Acari: Mesostigmata). After a period of 4 mo, we compared the abundance of arthropods on experimental birds to that of control birds with intact teeth. We used video to quantify the grooming rates of the captive birds, which groomed twice as much as wild birds. Experimental and control birds did not differ significantly in grooming time. Both groups virtually eradicated the chewing lice, but not feather mites or nasal mites. We found no support for the hypothesis that pectinate claws increase the efficiency of arthropod control by grooming. Experiments with wild birds are needed to test the hypothesis further under conditions in which birds devote less time to grooming.
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Ácaros y Garrapatas , Artrópodos , Enfermedades de las Aves , Infestaciones por Piojos , Phthiraptera , Animales , Bovinos , Infestaciones por Piojos/veterinaria , Infestaciones por Piojos/parasitología , Aseo Animal , Enfermedades de las Aves/parasitología , Aves , Animales SalvajesRESUMEN
Filarial nematodes of the Dipetalonema lineage include tick-borne filarioids that infect both domestic and wild vertebrate hosts, but they remain understudied in many cases. In this study, we conducted a molecular characterization of a Dipetalonema-like filarioid (DLF) recently identified in two tick species in French Guiana, South America. While the cox1 mitochondrial gene was the sole marker initially sequenced for describing DLF, its classification and phylogenetic relationship with other members of the Dipetalonema lineage were unclear. Therefore, we better characterized DLF through the sequencing of six additional gene markers and conducted phylogenetic analyses. Based on this multi-locus typing scheme, DLF exhibited significant divergence from known genera and species of filarioids, or other sequences available in public databases, suggesting its potential classification as a novel genus within the Dipetalonema lineage. Phylogenetic analyses further unveiled a close evolutionary relationship between DLF and all other filarioids associated with Acari (ticks and mites) within a robust monophyletic subclade in the Dipetalonema lineage. Overall, these findings confirm the existence of a specialized, Acari-borne group of filarioids and underscore the need for comprehensive investigations into their epidemiology and potential impact on animal health.
Title: Une analyse de séquences multi-locus dévoile un nouveau genre de nématodes filaires, associé aux tiques en Guyane française. Abstract: Les filaires de la lignée Dipetalonema comprennent des espèces transmises par les tiques qui infectent à la fois des hôtes vertébrés domestiques et sauvages, mais qui restent sous-étudiées dans de nombreux cas. Dans cette étude, nous avons réalisé une caractérisation moléculaire d'un filarioïde ressemblant à Dipetalonema (FRD) récemment identifié dans deux espèces de tiques en Guyane française. Alors que la séquence du gène mitochondrial cox1 était le seul marqueur génétique initialement séquencé pour décrire FRD, sa classification et sa relation phylogénétique avec d'autres membres de la lignée Dipetalonema étaient incertaines. Par conséquent, nous avons caractérisé plus précisément DLF en séquençant six gènes supplémentaires et en réalisant des analyses phylogénétiques. Sur la base de ce typage multi-locus, FRD présentait une divergence significative par rapport aux genres et espèces connus de filarioïdes, ou à d'autres séquences disponibles dans les bases de données publiques, suggérant sa classification potentielle en tant que nouveau genre au sein de la lignée Dipetalonema. Les analyses phylogénétiques ont en outre révélé une relation évolutive étroite entre FRD et tous les autres filarioïdes associés aux tiques et acariens au sein d'un sous-clade monophylétique dans la lignée Dipetalonema. Dans l'ensemble, ces résultats confirment l'existence d'un groupe spécialisé de filarioïdes transmis par les tiques et acariens et soulignent la nécessité d'études approfondies sur leur épidémiologie et leur impact potentiel sur la santé animale.
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Ácaros y Garrapatas , Nematodos , Garrapatas , Animales , Filogenia , Guyana Francesa/epidemiología , Análisis de SecuenciaRESUMEN
In this study, we report soft ticks from bat-inhabiting caves in different areas of Brazil. From 2010 to 2019, we collected 807 tick specimens from nine caves located in four Brazilian states among two biomes. Ticks were morphologically identified as Antricola guglielmonei (282 specimens), Ornithodoros cavernicolous (260 specimens), and Ornithodoros fonsecai (265 specimens). Whereas A. guglielmonei was collected on bat guano in hot caves, O. cavernicolous and O. fonsecai were collected in cracks and crevices on the walls of cold caves, sometimes in the same chamber. Morphological identifications were corroborated by molecular and phylogenetic analyses inferred from tick mitochondrial 16S rRNA gene partial sequences. The sequences of A. guglielmonei, O. cavernicolous and O. fonsecai collected in this study clustered with conspecific GenBank sequences from different localities of Brazil. Remarkably, a clade containing 12 sequences of O. fonsecai was clearly bifurcated, denoting a degree of genetic divergence (up to 5 %) of specimens from Cerrado/Atlantic Forest biomes with the specimens from the Caatinga biome. To further evaluate this divergence, we performed morphometric analysis of the larval stage of different O. fonsencai populations by principal component analysis, which indicated that the larvae from Caatinga populations were generally smaller than the larvae from other biomes. Some of the present A. guglielmonei specimens were collected from the type locality of Antricola inexpectata. Comparisons of these specimens with the type specimens of A. inexpectata and A. guglielmonei indicated that they could not be separated by their external morphology. Hence, we are relegating A. inexpectata to a synonym of A. guglielmonei. This proposal is corroborated by our phylogenetic analysis.
Asunto(s)
Ácaros y Garrapatas , Argasidae , Quirópteros , Ornithodoros , Animales , Argasidae/genética , Brasil , ARN Ribosómico 16S/genética , Ácaros y Garrapatas/genética , Filogenia , Larva/genéticaRESUMEN
BACKGROUND: Spotted fever group Rickettsia (SFGR) is the largest group of Rickettsia species of clinical and veterinary importance emerging worldwide. Historically, SFGR cases were linked to Rickettsia rickettsii, the causal agent of Rocky Mountain spotted fever; however, recently discovered species Rickettsia parkeri and Rickettsia amblyommatis have been shown to cause a wide range of clinical symptoms. The role of R. amblyommatis in SFGR eco-epidemiology and the possible public health implications remain unknown. METHODS: This study evaluated statewide tick surveillance and land-use classification data to define the eco-epidemiological relationships between R. amblyommatis and R. parkeri among questing and feeding ticks collected across South Carolina between 2021 and 2022. Questing ticks from state parks and feeding ticks from animal shelters were evaluated for R. parkeri and R. amblyommatis using reverse transcriptase quantitative polymerase chain reaction (RT-qPCR) on pooled samples. A Bayesian multivariable logistic regression model for pool testing data was used to assess associations between R. parkeri or R. amblyommatis infection and land-use classification variables among questing ticks. The Spearman correlation was used to evaluate the relationship between the two tested pathogens. RESULTS: The infection prevalence for R. amblyommatis was 24.8% (23.4-26.3%) among questing ticks, and 39.5% (37.4-42.0%) among feeding ticks; conversely, for R. parkeri it was 19.0% (17.6-20.5%) among questing ticks and 22.4% (20.3-24.5%) among feeding ticks. A negative, refractory correlation was found between the species, with ticks significantly more likely to contain one or the other pathogen, but not both simultaneously. The Bayesian analysis revealed that R. amblyommatis infection was positively associated with deciduous, evergreen, and mixed forests, and negatively associated with hay and pasture fields, and emergent herbaceous wetlands. Rickettsia parkeri infection was positively associated with deciduous, mixed, and evergreen forests, herbaceous vegetation, cultivated cropland, woody wetlands, and emergent herbaceous wetlands, and negatively associated with hay and pasture fields. CONCLUSIONS: This is the first study to evaluate the eco-epidemiological factors driving tick pathogenicity in South Carolina. The negative interactions between SFGR species suggest the possible inhibition between the two pathogens tested, which could have important public health implications. Moreover, land-use classification factors revealed environments associated with tick pathogenicity, highlighting the need for tick vector control in these areas.
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Ácaros y Garrapatas , Ixodidae , Infecciones por Rickettsia , Rickettsia , Garrapatas , Animales , Garrapatas/microbiología , South Carolina/epidemiología , Teorema de Bayes , Infecciones por Rickettsia/epidemiología , Infecciones por Rickettsia/microbiología , Ixodidae/microbiologíaRESUMEN
Cingulacarus Elsen is a monotypic genus of Trigynaspida based on C. gangeticus Elsen, collected from the scarabaeid beetle Scarabaeus gangeticus (Castelnau) (Col., Scarabaeidae) in the Democratic Republic of the Congo. Herein, a second species of the genus, C. kermanensis sp. nov. is described based on female and male specimens collected in southeastern Iran, in association with Oryctes elegans L. (Col., Scarabaeidae). The diagnosis of the genus Cingulacarus is revised, with a discussion of the impact on current generic keys for the family Diplogyniidae, and a proposal to eliminate the current subfamilial classification within that family.
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Ácaros y Garrapatas , Escarabajos , Ácaros , Femenino , Masculino , AnimalesRESUMEN
Ticks are obligate hematophagous parasites that can transmit to vertebrate hosts several pathogens, including viruses, bacteria, protozoa and helminths. Among these agents, some Borrelia species some Borrelia species cause disease in humans and other vertebrate hosts; therefore, they have medical and veterinary health importance. To gather additional information on Borrelia species in Brazil, the current study aimed to detect the presence of these species in Ornithodoros cavernicolous ticks collected in September 2019 from cement pipes that are used by bats as shelter in a farm located in the midwestern region of Brazil. DNA samples obtained from 18 specimens of O. cavernicolous were subjected of two polymerase chain reactions, targeting a segment of the Borrelia fla B gene. Of the samples tested, only one (6 %, 1/18) showed amplification. The nucleotide sequence of the amplified DNA showed more than 97 % (293/300) identity with a sequence of a Borrelia sp. detected in blood collected from a bat from Macaregua Cave, Colombia, and more than 97 % (292/300) detected in lungs from vampire bats from northeastern Brazil. The deduced amino acid sequences were identical to each other. Phylogenetic analysis indicated that these sequences formed a group of Borrelia species (putatively associated with bats) that is closely related to sequences of Borrelia species of the Lyme borreliosis group. Further investigations should be carried out in order to determine whether the sequence of the Borrelia sp. we found belongs to a new taxon. It will also be of great importance to determine which vertebrate hosts, besides bats, O. cavernicolous ticks can parasitize in order to investigate whether the Borrelia sp. we found may be transmitted and cause disease to the other vertebrate hosts.
Asunto(s)
Ácaros y Garrapatas , Argasidae , Borrelia , Quirópteros , Ornithodoros , Humanos , Animales , Ornithodoros/microbiología , Argasidae/genética , Borrelia/genética , Ácaros y Garrapatas/genética , Brasil/epidemiología , Quirópteros/parasitología , Filogenia , ADNRESUMEN
Molecular examination of representatives of Balaustium from several populations in SW Poland, performed using the sequence data from the mitochondrial cytochrome c oxidase subunit I, confirmed their common specific affiliation and identity with Balaustium murorum. The potential presence of distinct species in the studied material, preliminarily inferred from the discovery of clusters as a result of Principal Component Analysis exploring the metric data sets, was rejected due to the finding of only one haplotype, at intra- and inter-population sampling. An insight into meristic traits in larvae, focused on chaetotaxy of legs, revealed wider variation than hitherto recognized for the species. The variation was higher in laboratory-reared larvae compared to field-collected ones. The overall deviations from the mean character values at intra- and interpopulation levels, higher than hitherto observed for the species, vote for the reappraisal of the criteria adopted for discrimination of members of Balaustium with the application of an integrative approach.
Asunto(s)
Ácaros y Garrapatas , Animales , Larva/genética , Polonia , Fenotipo , Haplotipos , Filogenia , Variación GenéticaRESUMEN
OBJECTIVE: Scabiosis, the infestation of the skin with Sarcoptes scabiei, is a neglected tropical disease, with at least 200 million people being infested with the parasite at any time. It is estimated that scabies is responsible for 0.07% of the total burden of disease worldwide. Objective of this study is to perform a scientometric analysis of S. scabiei literature using the Web of Science Core Collection database for the years 1981-2020. METHODS: All documents indexed between 1981 and 2020 in scabies literature were analyzed by using a search string including keywords of "scabies", "Sarcoptes scabiei" and "S. scabiei" in Web of Science Core Collection database. We excluded all materials including data on the bacterium species named Streptomyces scabies and Streptomyces scabiei. RESULTS: Overall, 2,933 articles were retrieved on scabies, 66.3% of which were original article. With 663 publications the USA was the most productive country, while The International Journal of Dermatology was the journal with the highest number of publications on scabies. Half of the most productive institutions and seven of the top ten prolific authors were also from Australia. The National Health and Medical Research Council of Australia was the most supportive funding agency. With 4,706 citations, 2020 was the year with most references on scabies. The most cited publication was "The Global Burden of Skin Disease in 2010: An Analysis of the Prevalence and Impact of Skin Conditions" by Hay et al. in the Journal of Investigative Dermatology with a total of 565 citations. The most collaborative country was Australia and the most cooperative institution was the University of Melbourne. CONCLUSION: The majority of the studies were done in a given country while multicenter studies are very rare. It is recommended that more studies should be conducted on scabiosis in developing countries where the problem of scabies is the biggest.
Asunto(s)
Ácaros y Garrapatas , Sarcoptidae , Escabiosis , Humanos , Animales , Sarcoptes scabiei , Escabiosis/epidemiología , PielRESUMEN
The predatory mites of the Phytoseiidae family are crucial biological control agents widely utilized in biological pest management targeting phytophagous mites and insects. Key factors in these control strategies are that phytoseiids must be able to find their main target prey and to maintain high populations and efficacy. To reduce expenses and time-consuming production methods of mass rearing of phytoseiids, pollen and other factitious (i.e., non-natural/nontarget) hosts need to be present as an alternative food for predatory mite populations. The mass-rearing possibilities of these predators on alternative food sources, such as astigmatid mites (i.e., house and stored mites) and pollen, must be evaluated not only by the cost of rearing settings but on the basis of their efficiency maintenance in killing prey. The pest kill rate (km) is the average daily lifetime killing of the pest by the natural enemy under consideration and can represent a useful indicator for phytoseiids efficacy to rank them as BCAs on the basis of their effective killing/predation on target prey. In this study, we evidenced that 2 astigmatid mites, Glycyphagus domesticus (De Geer) and Lepidoglyphus destructor (Schrank), and Quercus ilex L. pollen can be successfully adopted as substitute food sources for mass rearing of the phytoseiid Neoseiulus californicus (MgGregor); then, we determined that these populations of BCAs maintained a consistent km at new/first impact on the main target pest, Tetranychus urticae Koch.
Asunto(s)
Ácaros y Garrapatas , Quercus , Animales , Agentes de Control Biológico , Alimentos , Polen , Conducta PredatoriaRESUMEN
Soft ticks (Argasidae) of the Pavlovskyella Pospelova-Shtrom subgenus are important vectors of relapsing fever spirochetes, which are agents of disease globally. South American representatives of the Pavlovskyella subgenus include 3 species: Ornithodoros (Pavlovskyella) brasiliensis Aragão, Ornithodoros (Pavlovskyella) furcosus Neumann, and Ornithodoros (Pavlovskyella) rostratus Aragão. Here, we describe a fourth species based on morphological and mitogenomic evidence of ticks collected in burrows of unknown hosts in central Chile. The larva of the new species separates from other South American soft ticks by the following combination of characters: 13 pairs of dorsolateral setae, dorsal plate hexagonal, hypostome blunt with denticles from apex almost to the base. Adults of this new species lack cheeks, possess a dorsoventral groove, and have humps, similar to O. (P.) brasiliensis; however, they lack bulging structures on the flanks of idiosoma. Moreover, females and males differ from O. (P.) rostratus by having 3 humps instead of spurs in tarsi I and from O. (P.) furcosus because of their smaller size and thinner anterior lip of the genital aperture in females. The phylogenetic analysis performed with mitogenomes of the Argasidae family depicts the new Pavlovskyella species from Chile in a monophyletic clade with other South American species in the subgenus, confirming a regional group.
Asunto(s)
Ácaros y Garrapatas , Argasidae , Ornithodoros , Femenino , Masculino , Animales , Argasidae/genética , Chile , Filogenia , Ornithodoros/genéticaRESUMEN
The genera of Heterozerconoidea are revised based on a species-level analysis of relationships in the group. The family Discozerconidae in its current state may be paraphyletic. Diagnoses for the genera are updated, and a catalog of all described species is provided. As part of this re-analysis two new genera, Amyzozercon and Ecuazercon, and four new species are described, and a key to the genera is provided. Possible evolutionary implications of the proposed set of relationships in terms of biogeography and the evolution of podospermy are discussed.
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Ácaros y Garrapatas , Filogenia , Animales , Ácaros y Garrapatas/clasificaciónRESUMEN
Leptotrombidium (Acari: Trombiculidae) mites are carriers of Orientia tsutsugamushi, the bacterial pathogen causing scrub typhus in humans. Classification of Leptotrombidium is vital because limited mite species carry O. tsutsugamushi. Generally, Leptotrombidium at the larval stage (approximately 0.2 mm in size) are used for morphological identification. However, morphological identification is often challenging because it requires considerable skills and taxonomic expertise. In this study, we found that the full-length sequences of the mitochondrial cytochrome c oxidase subunit 1 gene varied among the significant Leptotrombidium. On the basis of these, we modified the canonical deoxyribonucleic acid (DNA) barcoding method for animals by redesigning the primer set to be suitable for Leptotrombidium. Polymerase chain reaction with the redesigned primer set drastically increased the detection sensitivity, especially against Leptotrombidium scutellare (approximately 17% increase), one of the significant mites carrying O. tsutsugamushi. Phylogenetic analysis showed that the samples morphologically classified as L. scutellare and Leptotrombidium pallidum were further split into 3 and 2 distinct subclusters respectively. The mean genetic distance (p-distance) between L. scutellare and L. pallidum was 0.2147, whereas the mean distances within each species were 0.052 and 0.044, respectively. Within L. scutellare, the mean genetic distances between the 3 subclusters were 0.1626-0.1732, whereas the distances within each subcluster were 0.003-0.017. Within L. pallidum, the mean genetic distance between the 2 subclusters was 0.1029, whereas the distances within each subcluster were 0.010-0.013. The DNA barcoding uncovered a broad genetic diversity of Leptotrombidium, especially of L. scutellare and L. pallidum, the notable species carrying O. tsutsugamushi. We conclude that the DNA barcoding using our primers enables precise and detailed classification of Leptotrombidium and implies the existence of a subgenotype in Leptotrombidium that had not been found by morphological identification.
Asunto(s)
Ácaros y Garrapatas , Orientia tsutsugamushi , Tifus por Ácaros , Trombiculidae , Animales , Humanos , Tifus por Ácaros/microbiología , Orientia tsutsugamushi/genética , Filogenia , Bacterias , Variación GenéticaRESUMEN
Acarapis woodi (Rennie 1921) (Acari: Tarsonemidae) is one of the mites that settles in the respiratory system of honeybees (Apis mellifera L. (Hymenoptera, Apidae)) and distributed throughout the world. It causes significant economic losses on honey production. In Türkiye, studies on the existence of A. woodi are very limited and so far, no studies on the molecular diagnosis and phylogenetic of it have been reported in Türkiye. This study was conducted to investigate the prevalence of A. woodi in Türkiye, especially in areas where beekeeping is intense. Diagnosis of A. woodi was performed using both microscopic and molecular methods using specific PCR primers. Adult honeybee samples were collected from 1.193 hives in 40 provinces of Türkiye between 2018 and 2019. Based on identification studies, the presence of A. woodi was detected in a total of 3 hives (0.5%) in 2018 and 4 hives (0.7%) in 2019. This is the first report for determination of A. woodi in Türkiye.
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Ácaros y Garrapatas , Miel , Ácaros , Varroidae , Abejas , Animales , Filogenia , Ácaros/genética , Reacción en Cadena de la PolimerasaRESUMEN
Two false spider mite species (Tetranychoidea: Tenuipalpidae) are reported in Greece. One new species, Aegyptobia insularis Stathakis and Vrettos sp. nov., collected from the Mediterranean shrub Phagnalon rupestre ssp. graecum (Asteraceae), is described. Dolichotetranychus summersi Pritchard and Baker is found on a new and probably natural host plant, the common couch grass Elymus repens (Poaceae); this is the first record of this mite in the Palearctic region. Females and deutonymphs of D. summersi are redescribed, based on the specimens from Greece.
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Ácaros y Garrapatas , Tetranychidae , Femenino , Animales , Grecia , Plantas , PoaceaeRESUMEN
Neocarus platensis is redescribed from part of the syntype series collected in Argentina and lectotype specimens are designated. The remaining syntype material from Uruguay represents a new species, herein named Neocarus paraplatensis sp. nov. Taxonomic problems within the Opilioacaridae are discussed in light of a comparative morphological discussion including setae quantity variation.
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Ácaros y Garrapatas , AnimalesRESUMEN
Two new mite species of the family Cunaxidae (Acari, Prostigmata)-Cunaxa asiatica sp. nov. and C. smileyi sp. nov.-are described from Vietnam, based on females. Cunaxa asiatica sp. nov. is similar to C. doxa (Chaudri, 1980) in having the medial hysterosomal shield smooth and bearing setae c1-e1, c2, but differs from the latter by the presence of 1 sts, finger-like palpofemoral apophysis and smooth setae c1-e1 on basifemora IV (vs. 2 sts, uncinate palpofemoral apophysis and spiculate c1-e1 in C. doxa). Cunaxa smiley sp. nov. is similar to C. oblongostriata Kalúz and Ermilov, 2022 in having 4-4-4-4 sts on telofemora I-IV and 2 solenidia on genu II, but differs from the latter by the presence of 3-3-3-0 sts on basifemora I-IV, 1 asl and 5 sts on genu IV, and well developed medial hysterosomal shield (vs. basifemora I-IV setal formula of 3-3-3-1 sts, genu IV bearing 7 sts, and the hysterosomal medial shield absent in C. oblongostriata).
Asunto(s)
Ácaros y Garrapatas , Ácaros , Femenino , AnimalesRESUMEN
The stimulation of biological processes by sublethal doses of insecticides or other stressors is known as hormesis. Here, we have evaluated whether exposure to field-relevant or low concentrations of neonicotinoids induce changes in the reproductive capacity of the bulb mite Rhizoglyphus robini (Acari: Acaridae). Among the tested neonicotinoids imidacloprid, thiamethoxam, and dinotefuran, the highest hormetic effect on the reproduction of R. robini occurred 24 h after the 48 h exposure period to imidacloprid at concentrations of 70 and 140 mg a.i./L. Despite the stimulating effects of imidacloprid on mite reproduction, no significant differences were observed in the offspring (F1) for biological aspects including egg hatch rate, embryonic period and sex ratio, while an increase was found in the duration of development time from egg to adult. Evaluation of the detoxification enzyme activities of treated adults showed that the highest activity of carboxyl/cholinesterases, cytochrome P450s, and glutathione S-transferases was obtained when exposed to 70, 140 and 70 mg a.i./L imidacloprid, immediately after the exposure period, respectively. Also, an increase in the activity of the antioxidant enzyme catalase was observed compared to that of the control. After imidacloprid pretreatment (140 mg a.i./L), the tolerance of adult mites to diazinon was increased about two-fold. This study shows that exposure to imidacloprid can induce hormetic effects on R. robini and could severely complicate its control due to a higher reproduction, enhanced detoxification enzyme activities, and increased tolerance against other pesticides.
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Ácaros y Garrapatas , Acaridae , Insecticidas , Animales , Insecticidas/toxicidad , Hormesis , Neonicotinoides/toxicidad , Nitrocompuestos/toxicidadRESUMEN
OBJECTIVE: To investigate the genetic diversity and genetic differentiation of different geographical isolates of Gohieria fusca. METHODS: G. fusca isolates were sampled from Wuhu (WH), Bengbu (BB) and Bozhou cities (BZ) of Anhui Province and Jiaxing City of Zhejiang Province (JX). Mitochondrial cytochrome b (Cytb) and ribosomal internal transcribed spacer (ITS) genes were amplified in WH, BB, BZ and JX isolates of G. fusca using PCR assay. The gene sequences were edited and aligned using the software Chromas 2 and DNASTAR 1.00, and the haplotype, haplotype diversity (Hd) and nucleotide polymorphism (Pi) of each isolate were calculated using the software DnaSP 5.10.00. The genetic differentiation among isolates (Fst) and gene flow value (Nm) were estimated using the software MEGA 10.2, and a phylogenetic tree was built. Tests of neutrality and analysis of molecular variance (AMOVA) were performed using the software Arlequin 3.1 and a haplotype network was built based on the Median-Joining network using the software Network 10.2. RESULTS: PCR assay showed that the sizes of the Cytb and ITS genes were 372 bp and 1 301 to 1 320 bp, respectively. All four isolates of G. fusca presented high genetic diversity based on mitochondrial Cytb and ITS genes (Hd = 0.804, Pi = 0.006 91). AMOVA showed genetic differentiation among geographical isolates of G. fusca (Fst = 0.202 40, P < 0.05), and the genetic variation was mainly caused by intra-population variations (79.76%). Gene flow analysis showed a high level of gene flow among G. fusca isolates (Nm > 1). Tests of neutrality based on Cytb gene measured a Tajima's D value of -1.796 31 (P < 0.05) and a Fu's FS value of -3.293 98 (P < 0.05) in WH isolate of G. fusca, indicating population expansion in WH isolate of G. fusca. Haplotype network analysis and phylogenetic analysis revealed no remarkable geographical distribution pattern among different geographical isolates of G. fusca. All four isolates of G. fusca presented high genetic diversity (Hd = 0.985, Pi = 0.011 97). AMOVA showed moderate level of genetic differentiation between four isolates (Fst = 0.104 62, P < 0.05). The tests of neutrality based on ITS genes measured a Tajima's D value of -6.088 20 and a Fu's FS value of -1.935 99 (both P > 0.05) in the whole isolate of G. fusca, indicating no obviously population expansion. CONCLUSIONS: The four geographical isolates of G. fusca have high genetic diversity and remarkable genetic differentiation. Since a high level of gene flow is detected among different geographical isolates of G. fusca, no obvious geographical distribution pattern of G. fusca is found.
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Ácaros y Garrapatas , Citocromos b , Variación Genética , Citocromos b/genética , ADN Mitocondrial/genética , Geografía , Haplotipos , Filogenia , Ácaros y Garrapatas/genética , AnimalesRESUMEN
Sarcoptes scabiei (S. scabiei) is an ectoparasite that can infest humans and 150 mammalian host species, primarily causing pruritus, crust, and alopecia. However, neither the pathological process of host skin under S. scabiei infection nor the mechanism of S. scabiei infection in regulating apoptosis and keratinization of host skin has been studied yet. In this study, a total of 56 rabbits were artificially infested with S. scabiei, and the skin samples were collected at seven different time points, including 6 h, 12 h, day 1, day 3, 1 week, 4 weeks, and 8 weeks, whereas a group of eight rabbits served as controls. We measured epidermal thickness by H&E staining, observed the skin ultrastructure by electron microscopy, and detected the degree of skin apoptosis by TUNEL staining. The level of transcription of genes related to apoptosis and keratinization was detected by quantitative real-time PCR (qRT-PCR), and the level of Bcl-2 protein expression was further detected using immunohistochemistry. Our results showed that, with increased infestation time, the epidermal layer of the rabbit skin exhibited significant thickening and keratinization, swollen mitochondria in the epidermal cells, and increased skin apoptosis. The level of caspase-1, 3, 8, 10, 14, and Bcl-2 mRNA expression was increased, whereas the level of keratin 1 and 5 was decreased after S. scabiei infestation. In conclusion, S. scabiei infestation causes thickening of the epidermis, which may be related to apoptosis-induced proliferation and skin keratinization.
Asunto(s)
Ácaros y Garrapatas , Sarcoptidae , Escabiosis , Piel , Animales , Humanos , Conejos , Apoptosis , Mamíferos , Sarcoptes scabiei/genética , Escabiosis/patología , Queratinas/metabolismo , Piel/metabolismoRESUMEN
Berries comprise an economically important group of crops. Knowledge about their arthropod pests and biological control agents is important in the development of more efficient integrated pest management programs. Identification of potential biocontrol agents based solely on morphological attributes may be difficult and so molecular techniques should be incorporated. Here we studied the species diversity of predatory mites in the family Phytoseiidae, and how this diversity is affected by the berry species and crop management approaches, specifically pesticide application regimes. We sampled 15 orchards in the State of Michoacán, Mexico. Sites were selected based on berry species and pesticide regimes. Mite identification was achieved by combining morphological attributes and molecular techniques. Phytoseiidae diversity was compared amongst blackberry, raspberry and blueberry. Subsequently we studied the effect of berry species and pesticide regime on the abundance of the most prevalent phytoseiid species. We identified 11 species of phytoseiid mites. The greatest species diversity was found in raspberry, followed by blackberry and then blueberry. The most abundant species were Typhlodromalus peregrinus and Neoseiulus californicus. The abundance of T. peregrinus was significantly affected by pesticide application but not by berry species. In contrast, abundance of N. californicus was significantly affected by berry species but not by pesticide regime.