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Accurate differentiation and identification of flea species are essential for both basic and applied research on fleas, as well as for the diagnosis of flea-borne diseases. However, distinguishing between flea species can be challenging, especially among those with minimal morphological differences. Therefore, some scholars have suggested the necessity of comprehensive revisions to the classification of fleas, incorporating morphological, molecular, and phylogenetic data. In this study, we focused on classifying the rodents' parasitic fleas in southeastern China and provided molecular and phylogenetic data. We also described a new subspecies Ctenophthalmus breviprojiciens fujiansis n. ssp. A total of 392 fleas were collected from 8 species of rodents in 10 counties. Morphologically, they belonged to 10 species, 9 genera and 5 families. Barcode identification based on COI gene and phylogenetic analysis based on five genetic markers (18S rDNA, 28S rDNA, EF-1a, COI, COII) revealed that the molecular and morphological identification of Xenopsylla cheopis, Aviostivalius klossi bispiniformis, Leptopsylla segnis, Monopsyllus anisus and Ctenocephalides felis felis were consistent. The taxonomic status of Neopsylla specialis minpiensis and Peromyscopsylla himalaica sinica as subspecies is questionable due to significant intraspecific genetic distance, and further morphological and molecular data are required to determine if they should be elevated to species level. The molecular identification of C. breviprojiciens n. ssp., N. dispar fukienensis, and Nosopsyllus nicanus could not be completed at this time due to a lack of sequences for related species in existing GenBank databases. Additionally, phylogenetic relationships of 31 species from 9 genera and 5 families of Siphonaptera were inferred based on five molecular markers (18S rDNA, 28S rDNA, EF-1a, COI and COII) using Maximum Likelihood analyses. The analyses revealed that various taxa of Siphonaptera are monophyletic at the subspecies, species, and genus levels. However, at the family level, Leptopsyllidae, Ceratophyllidae, Pulicidae, and Pygiopsyllidae are all monophyletic, while Ctenophthalmidae is paraphyletic. we support the view of some authors that revising the catchall group Ctenophthalmidae and elevating each of its constituent subfamilies to family status., Competing Interests: Declarations Competing interests The authors declare no competing interests., (© 2024. The Author(s).)

Wildlife are hosts of ectoparasites, such as fleas and ticks that may transmit human and animal pathogens. Little is known about the ecology of many ectoparasite species native to southern Texas, or their role in pathogen maintenance and transmission. Much attention has been given to the role of nonnative nilgai antelope as cattle fever tick hosts and agents of dispersal, but little attention has been given to other ectoparasites that may utilize nilgai antelope as hosts. As southern Texas is a hot-spot for flea-borne (murine) typhus, it is important to examine flea species presence, abundance, and host use in this region. Fleas were opportunistically collected during wildlife depredation activities, from hunter-harvested animals, or during handling in the course of other research activities in several southern Texas counties. A total of 9 wildlife species were sampled, from which 3 flea species were identified. A total of 83 Pulex porcinus (Jordan and Rothschild) were collected from nilgai, coyotes, bobcats, javelina, feral swine, and a black-tailed jackrabbit. In total, 9 Euhoplopsyllus glacialis affinis (Baker) were collected from cottontail rabbits, and 1 Echidnophaga gallinacea (Westwood) was collected from a raccoon. To our knowledge, this represents the first report of fleas from nilgai antelope. Pulex porcinus, although often considered a specialist species, was collected from a wide range of hosts, including 2 (nilgai antelope and black-tailed jackrabbit) that represent new host records for this species. The role of P. porcinus as a pathogen vector is unknown, but its apparent abundance in this region warrants further investigation., (Published by Oxford University Press on behalf of Entomological Society of America 2024.)

We studied spatial variation in the effects of environment and network size on species positions and roles in multiple flea-mammal networks from four biogeographic realms. We asked whether species positions (measured as species strength [SS], the degree of interaction specialization [d'], and the eigenvector centrality [C]) or the roles of fleas and their hosts in the interaction networks: (a) are repeatable/conserved within a flea or a host species; (b) vary in dependence on environmental variables and/or network size; and (c) the effects of environment and network size on species positions or roles in the networks depend on species traits. The repeatability analysis of species position indices for 441 flea and 429 host species, occurring in at least two networks, demonstrated that the repeatability of SS, d', and C within a species was significant, although not especially high, suggesting that the indices' values were affected by local factors. The majority of flea and host species in the majority of networks demonstrated a peripheral role. A value of at least one index of species position was significantly affected by environmental variables or network size in 41 and 36, respectively, of the 52 flea and 52 host species that occurred in multiple networks. In both fleas and hosts, the occurrence of the significant effect of environment or network size on at least one index of species position, but not on a species' role in a network, was associated with some species traits., (© 2024 International Society of Zoological Sciences, Institute of Zoology/Chinese Academy of Sciences and John Wiley & Sons Australia, Ltd.)

To understand the ecoepidemiology of fleas and their interactions with domestic and wild animals, it is necessary to decode the cycles of flea abundance in relation to host species and environmental factors. The province of Misiones, known for its biodiversity and land use changes, provides an excellent study location. We assessed the diversity, prevalence, abundance, and parasitic intensity of fleas collected from 1153 rodents and opossums in various environments in the Upper Paraná Atlantic Forest of Argentina, considering phytogeography and land use. Our findings were consistent with previous studies conducted in humid regions of Argentina and the Atlantic Forest in Brazil. Hosts with high population density exhibited greater flea prevalence and abundance, and widely distributed hosts showed higher flea species richness and diversity. Significant similarities in flea similarity indices among phytogeographic areas, especially in forest. Environments with an anthropogenic gradient exhibited marked dissimilarities, with higher species richness and diversity in less disturbed sites. These parameters may be influenced by the presence of polyxenous Ctenocephalides, Polygenis, and Adoratopsylla fleas co-infesting opossum in urban areas. These findings provide valuable insights into the ecoepidemiology of fleas, their relationships with host species, and the impact of environmental factors in a strategic Atlantic forest ecoregion.

Fleas, along with one of their host species, Meriones unguiculatus, possess the capability to act as vectors in the transmission of plague. Parasitism by fleas may markedly influence the physiology and immune system of their hosts. Gut microbiota plays an important role in the growth and development of rodents. However, few studies have explored the impacts of ectoparasitic flea on the gut microbiome of rodents. This study investigated the immunological responses and changes in the gut microbial diversity and composition in both wild and laboratory rodents infested with fleas and laboratory rodents infested with Ctenocephalides felis. We measured immune reactions post-infestation by enzyme-linked immunosorbent assay (ELISA) and explored the effects of ectoparasitic infestation on the diversity and composition of the rodent gut microbiota in microbiome studies by 16S rRNA gene sequencing techniques. After flea infestation, results from 16S rRNA gene sequencing techniques indicated a significant increase in alpha diversity, affecting the composition of the gut microbiota. At the genus level, the abundance of the harmful bacterium Desulfovibrio increased. Beta diversity analyses showed significant differences between the gut microbiota of the experimental and control groups. ELISA results revealed significantly elevated levels of IgG in parasitized mice, while the differences in IgA levels were not significant. Flea infections affect the composition and diversity of the gut microbiota in the M. unguiculatu, and it has been found that the biomarker Desulfovibrio increases following flea infection in these rodents. Our results indicate that the gut microbiota can regulate the stability of the rodent-flea system. These findings may provide a foundation for exploring preventive measures against plague and aid in developing more effective treatments for the infection., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Social cognitive models are useful for improving our understanding of the relationship between people's health beliefs and disease risks and have been widely employed in human medicine. In veterinary science, there is little research about owners' perceptions of pet health and parasitic infections/infestations, despite the risk of transmission of zoonotic pathogens by ectoparasites. This study investigated the effects of demographic factors on pet owner's perception of ectoparasite infestation risk and behaviours related to animal health in southeast Queensland, Australia employing the Health Belief Model (HBM). A total of 241 dog owners were surveyed in 2018. The electronic survey was generated through SurveyMonkey and distributed utilising UQ SVS and Royal Society for the Prevention of Cruelty to Animals (RSPCA) email networks, informative posters and brochures placed in selected veterinary clinics, and in-person visits to dog parks. The relationship between dog owners' perception of flea and tick infestation risk was assessed using an adaptation of the Health Belief Model, social cognitive framework for health protection. Most survey respondents were between 26 and 45 years of age (40%), identified themselves as females (83%) and had a bachelor's degree (43%). Our results indicate that female owners had greater level of health concern related to ectoparasites compared to males. Similarly, owners aged 18 to 25, with a grade 10 to 12 level of attained education and living predominately in a rural setting showed greater level of health concern related to ectoparasite infestations. The results also indicated that cat owners had on average, higher levels of health concern than dog owners. Our study indicates that the perceptions of pet owners towards perception of flea and tick infestation risk varies demographically, and owner education is an important predictor of prevention behaviours towards tick and flea infestation of pets., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Flea-borne diseases are endemic in Texas, U.S.A., with an increasing incidence of flea-borne typhus and cat scratch disease. Knowledge of flea natural history could provide information to protect public health, yet many knowledge gaps remain outside of plague-endemic regions. Our objective was to characterize seasonal activity patterns of fleas on common mammalian wildlife species and test fleas and wildlife for Rickettsia and Bartonella pathogens. We performed one year of monthly trapping for rodents and medium-sized mammals in a national forest with high recreational use and urban encroachment in East Texas. From 90 mammal captures representing seven species, 101 fleas were collected representing Polygenis spp., Ctenocephalides felis , and Orchopeas species. Virginia opossums ( Didelphis virginianus ) hosted 99% of the collected fleas (100 fleas) and a single flea was on an eastern woodrat ( Neotoma floridana ). Flea infestation prevalence of opossums was 79% (23/29). Mean flea abundance was 4.39 fleas, with intensity peaking in spring. One cat flea removed from an opossum was positive for Bartonella henselae . Furthermore, we identified tissue or blood of four raccoons ( Procyon lotor ) and one golden mouse ( Ochrotomys nuttalli ) positive for Rickettsia amblyommatis . These findings provide an ecological basis for the maintenance of vectors and pathogens from sylvatic settings.

Co-invasion, characterized by the simultaneous introduction of hosts and parasites with the latter establishing themselves in native hosts, is a phenomenon of ecological concern. Rattus rattus, a notorious invasive species, has driven the extinction and displacement of numerous avian and mammalian species and serves as a key vector for diseases affecting both humans and wildlife. Among the parasites hosted by R. rattus are fleas, which exhibit obligate parasitic behaviour, a generalist nature and high prevalence, increasing the likelihood of flea invasion. Simultaneously, invasive species can serve as hosts for native parasites, leading to potential amplification or dilution of parasite populations in the environment. In Chile, R. rattus has been present since the 17th century because of the arrival of the Spanish colonizers through the ports and has spread throughout urban, rural and wild Chilean territories. This study aims to evaluate whether co-invasion of native fleas of invasive rats occurs on native rodents in Chile and to determine whether black rats have acquired flea native to Chile during their invasion. For this, we captured 1132 rodents from 26 localities (20° S-53° S). Rattus rattus was found coexisting with 11 native rodent species and two species of introduced rodents. Among the native rodents, Abrothrix olivacea and Oligoryzomys longicaudatus exhibited more extensive sympatry with R. rattus. We identified 14 flea species associated with R. rattus, of which only three were native to rats: Xenopsylla cheopis, Leptopsylla segnis and Nosopsyllus fasciatus. These three species presented a higher parasite load in black rats compared to native fleas. Leptopsylla segnis and N. fasciatus were also found associated with native rodent species that cohabit with R. rattus. The remaining species associated with R. rattus were fleas of native rodents, although they were less abundant compared to those associated with native rodents, except for Neotyphloceras pardinasi and Sphinctopsylla ares. Although there has been evidence of flea transmission from rats to native species, the prevalence and abundance were relatively low. Therefore, it cannot be definitively concluded that these fleas have established themselves in native rodent populations, and hence, they cannot be classified as invasive fleas. This study underscores R. rattus' adaptability to diverse environmental and geographical conditions in Chile, including its capacity to acquire fleas from native rodents. This aspect has critical implications for public health, potentially facilitating the spread of pathogens across various habitats where these rats are found., (© 2024 Royal Entomological Society.)

With the intensity and frequency of wildfires increasing rapidly, the need to study the ecological effects of these wildfires is also growing. An understudied aspect of fire ecology is the effect fires have on parasite-host interactions, including ectoparasites that might be pathogen vectors. Although some studies have examined the impacts of fire on ticks, studies on other ectoparasites, including pathogen vectors, are rare. To help address this knowledge gap, we examined the abiotic and biotic factors that predict the likelihood and extent of parasitism of deer mice (Peromyscus maniculatus) by fleas within a landscape of unburned and recovering burned (>9 yr postfire) mixed conifer forests. We sampled 227 individual deer mice across 27 sites within the Jemez Mountains of northern New Mexico in 2022 and quantified measures of parasitism by fleas (primarily Aetheca wagneri). These sites were distributed in both unburned areas (n = 15) and recovering burned areas (n = 12), with the latter derived from 2 large fires, the Las Conchas fire (2011) and the Thompson Ridge fire (2013). Using these data, we tested for differences in prevalence, mean abundance, and mean intensity of fleas on deer mice, focusing on the predictive importance of host sex and fire history. We also created generalized linear mixed-effects models to investigate the best host and environmental predictors of parasitism by fleas. Approximately a decade postfire, we found minimal evidence to suggest that fire history influenced either the presence or intensity of fleas on deer mice. Rather, at the current forest-regeneration stage, the extent of parasitism by fleas was best predicted by measures of host sex, body condition, and the trapline's ability to accumulate water, as measured through topography. As host body condition increased, the probability of males being parasitized increased, whereas the opposite pattern was seen for females. Male mice also had significantly greater flea loads. Among potential abiotic predictors, the topographic wetness index or compound topographic index (a proxy for soil moisture) was positively related to flea intensity, suggesting larger flea populations in burrows with higher relative humidity. In summary, although fire may potentially have short-term impacts on the likelihood and extent of host parasitism by fleas, in this recovering study system, host characteristics and topographic wetness index are the primary predictors of parasitism by fleas., (© American Society of Parasitologists 2024.)

We present an annotated checklist of fleas (Siphonaptera) known to occur in the state of Delaware based on an examination of Siphonaptera collections at the University of Delaware and the Carnegie Museum of Natural History, as well as new specimens of fleas we collected from wildlife, other hosts, and tick flags. We review published records and compile them herein with our new records, which include 3 species previously unreported from Delaware. With these additions, there are now 18 flea species from 19 avian and mammalian hosts documented from Delaware., (© The Author(s) 2024. Published by Oxford University Press on behalf of Entomological Society of America.)

We applied a novel framework based on network theory and a concept of modularity that estimates congruence between trait-based ( = functional) co-occurrence networks, thus allowing the inference of co-occurrence patterns and the determination of the predominant mechanism of community assembly. The aim was to investigate the relationships between species co-occurrence and trait similarity in flea communities at various scales (compound communities: across regions within a biogeographic realm or across sampling sites within a geographic region; component communities: across sampling sites within a geographic region; and infracommunities: within a sampling site). We found that compound communities within biogeographic realms were assembled via environmental or host-associated filtering. In contrast, functional and spatial/host-associated co-occurrence networks, at the scale of regional compound communities, mostly indicated either stochastic processes or the lack of dominance of any deterministic process. Analyses of congruence between functional and either spatial (for component communities) or host-associated (for infracommunities) co-occurrence networks demonstrated that assembly rules in these communities varied among host species. In component communities, stochastic processes prevailed, whereas environmental filtering was indicated in 4 and limiting similarity/competition in 9 of 31 communities. Limiting similarity/competition processes dominated in infracommunities, followed by stochastic mechanisms. We conclude that assembly processes in parasite communities are scale-dependent, with different mechanisms acting at different scales.

We searched for common patterns in parasite ecology by investigating species and host contributions to the beta-diversity of infracommunities (=assemblages of parasites harboured by a host individual) in helminths of three species of South African ungulates and fleas of 11 species of South American rodents, assuming that a comparison of patterns in distinctly different parasites and hosts would allow us to judge the generality or, at least, commonness of these patterns. We used data on species' composition and numbers of parasites and asked whether (i) parasite species' attributes (life cycle, transmission mode, and host specificity in helminths; possession of sclerotized combs, microhabitat preference, and host specificity in fleas) or their population structure (mean abundance and/or prevalence) and (ii) host characteristics (sex and age) affect parasite and host species' contributions to parasite beta-diversity (SCBD and HCBD, respectively). We found that parasite species' morphological and ecological attributes were mostly not associated with their SCBD. In contrast, parasite SCBD, in both ungulates and rodents, significantly increased with either parasite mean abundance or prevalence or both. The effect of host characteristics on HCBD was detected in a few hosts only. In general, parasite infracommunities' beta-diversity appeared to be driven by variation in parasite species rather than the uniqueness of the assemblages harboured by individual hosts. We conclude that some ecological patterns (such as the relationships between SCBD and parasite abundance/prevalence) appear to be common and do not differ between different host-parasite associations in different geographic regions, whereas other patterns (the relationships between SCBD and parasite species' attributes) are contingent and depend on parasite and host identities., (Copyright © 2024 Australian Society for Parasitology. Published by Elsevier Ltd. All rights reserved.)

Background: Fleas, considered to be the main transmission vectors of Bartonella, are highly prevalent and show great diversity. To date, no investigations have focused on Bartonella vectors in Southeast China. The aim of this study was to investigate the epidemiological and molecular characteristics of Bartonella in fleas in Southeast China., Methods: From 2016 to 2022, flea samples (n = 1119) were collected from 863 rodent individuals in seven inland and coastal cities in Southeast China. Flea species, region, gender, host species and habitat were recorded. The DNA samples from each individual flea were screened by real-time PCR for the Bartonella ssrA gene. All positive samples were confirmed by PCR based on the presence of the gltA gene and sequenced. The factors associated with Bartonella infection were analyzed by the Chi-square test and Fisher's exact test. ANOVA and the t-test were used to compare Bartonella DNA load., Results: Bartonella DNA was detected in 26.2% (293/1119) of the flea samples, including in 27.1% (284/1047) of Xenopsylla cheopis samples, 13.2% (5/38) of Monopsyllus anisus samples, 8.3% (2/24) of Leptopsylla segnis samples and 20.0% (2/10) of other fleas (Nosopsyllus nicanus, Ctenocephalides felis, Stivalius klossi bispiniformis and Neopsylla dispar fukienensis). There was a significant difference in the prevalence of Bartonella among flea species, sex, hosts, regions and habitats. Five species of Bartonella fleas were identified based on sequencing and phylogenetic analyses targeting the gltA gene: B. tribocorum, B. queenslandensis, B. elizabethae, B. rochalimae and B. coopersplainsensis., Conclusions: There is a high prevalence and diversity of Bartonella infection in the seven species of fleas collected in Southeast China. The detection of zoonotic Bartonella species in this study, including B. tribocorum, B. elizabethae and B. rochalimae, raises public health concerns., (© 2024. The Author(s).)

Background: Fleas belonging to the Pulicidae are prevalent ectoparasites infesting mammals and birds in Iran. This study focused on genetically identifying and characterizing Ctenocephalides canis collected both off-host and infesting humans and various domestic animals in the country., Methods: A total of 918 adult flea samples were collected from 10 sites in western and northwestern Iran between April 2018 and May 2019. Out of these, 71 specimens were found off-host, while the remaining fleas were collected from humans (121), sheep (126), goats (184), and dogs (416). Morphological identification at the genus level was performed on all fleas, and ten selected specimens selected based on the sampling sites and hosts were subjected to molecular detection at the species level by using partial amplification and sequencing of the internal transcribed spacer 1 and 2, as well as the cytochrome oxidase I (COXI) markers., Results: The morphological identification confirmed all fleas as Ctenocephalides spp. Alignment and phylogenetic analysis of nuclear and mitochondrial partial sequences confirmed the presence of C. canis. However, molecular divergence was observed among the ten isolates based on the ITS1 and ITS2 with diversity rates estimated at 0.15% and 3.36%, respectively. Notably, the analysis of the COXI marker revealed no molecular divergence among the partial sequences representing the ten studied isolates from C. canis., Conclusions: This study explores the diversity of C. canis in the western and northwestern regions of Iran, providing insights into their molecular taxonomy and potential role as disease vectors in these areas., (© 2024. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

This epidemiological survey aims to provide an update on the main flea species that parasitize domestic animals in the Western Andalusia assessing several ecological features that could be considered as possible risk factors for flea infestation. Over a 19-month period (June 2021 to January 2023), we obtained a total of 802 flea samples from 182 dogs (Canis lupus familiaris, Carnivora: Canidae, Linnaeus, 1758) and 78 cats (Felis silvestris catus, Carnivora: Felidae, Schreber, 1775). For each parasitized host, an epidemiological survey was completed, including the following information: geographical origin, age, sex, rural or urban habitat, type of animal's lifestyle (domestic or non-domestic), health status, cohabiting or not with other animals and the total number of collected fleas. The most common species was Ctenocephalides felis (Siphonaptera: Pulicidae) (Bouché, 1835) with a total of 713 specimens, which accounted for 89% of the total fleas. The second most abundant species was Pulex irritans (Siphonaptera: Pulicidae) (Linnaeus, 1758) with a total of 46 collected fleas (6% of the total). The remaining species identified were Archaeopsylla erinacei (Siphonaptera: Pulicidae) (Bouché, 1835) (25 specimens), Spilopsyllus cuniculi (Siphonaptera: Pulicidae) (Dale, 1878) (12 specimens) and Ctenocephalides canis (Siphonaptera: Pulicidae) (Curtis, 1826) (6 specimens), which accounted for 3%, 1% and 1%, respectively, of the total fleas collected. The months with the highest number of collected fleas were, in ascending order, May 2022, September 2021 and July 2021. Dogs had a greater diversity of flea species, and flea sex ratios were female biased in all identified species and among all studied hosts. Finally, we identified some potential host risk factors that promoted higher flea intensities, such as living in rural areas, or presenting other pathologies., (© 2024 The Authors. Medical and Veterinary Entomology published by John Wiley & Sons Ltd on behalf of Royal Entomological Society.)

Herein we present the first-known case report of a structural infestation by the bird flea (Dasypsyllus gallinulae perpinnatus) (Dale 1878) in the United States. In March of 2023, the San Mateo County Mosquito and Vector Control District was contacted by a resident in South San Francisco, CA who reported the presence of fleas inside their condominium. The resident had 2 dogs who were on oral flea medication and only 1 inhabitant out of 4 reported receiving flea bites. The front walkway, backyard, and garage were flagged and a small passerine nest was removed from a fire alarm bell in the front walkway. A total of 31 fleas (13 males, 18 females) were collected by flagging from the front entryway underneath the nest. One female flea was collected from the backyard, and 20 (9 males, 11 females) were collected by the resident from inside the house. A total of 387 fleas (163 males, 224 females) were collected from the nest of a small passerine. All life stages (egg, larvae, pupae, and adult) were observed within the nest. Additional parasites in the nest included bird lice and larval western black-legged ticks (Ixodes pacificus, Cooley and Kohls 1943). Research should be conducted into whether bird fleas are capable of transmitting avian pathogens to humans and this information should be communicated to healthcare providers as part of a One Health approach. Additionally, resources to aid in species-level flea identification should be made accessible to pest control operators as this will aid the development of targeted treatments as part of an integrated pest management plan., (© The Author(s) 2024. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)

Background: Feline-associated hemotropic Mycoplasma (hemoplasmas) are believed to be transmitted by two primary mechanisms: (1) direct transmission via fighting and (2) vector-borne transmission by the cat flea (Ctenocephalides felis). While the efficiency of transmission by C. felis appears low, most manuscripts focus on the prevalence of hemoplasmas in wild-caught fleas and report either a very low (< 3%) or a high (> 26%) prevalence. Therefore, we aimed to assess the influence of sample processing and PCR methods on C. felis hemoplasma infection prevalence., Methods: A systemic review of PubMed articles identified 13 manuscripts (1,531 fleas/flea pools) that met the inclusion criteria (performed PCR for >1 hemoplasma on C. felis collected from cats). Risk of bias was assessed utilizing the ROBINS-E tool. Meta-analysis performed in R of these manuscripts found that not washing samples and a common set of 16S rRNA primers first published in Jensen et al. 2001 were associated with increased hemoplasma prevalence. To evaluate the influence of washing on newly collected fleas, we assessed the hemoplasma status of 20 pools of 5 C. felis each, half of which were washed and half not washed., Results: Flea washing did not influence the detection of hemoplasma but instead amplified Spiroplasma. To assess non-specific amplification with the Jensen et al. 2001 primers, 67 C. felis samples (34% previously reported hemoplasma infected) were subject to PCR and sequencing. By this method, hemoplasma was detected in only 3% of samples. In the remaining "hemoplasma infected" fleas, PCR amplified Spiroplasma or other bacteria., Conclusions: Therefore, we concluded that hemoplasma infection in C. felis is rare, and future flea prevalence studies should sequence all positive amplicons to validate PCR specificity. Further investigation of alternative methods of feline-associated hemoplasma transmission and the ability of C. felis to maintain hemoplasma infection is necessary., (© 2024. The Author(s).)

Functional signal in an interaction network is a phenomenon in which species resembling each other in their traits interact with similar partners. We tested the functional signal concept in realm-specific and regional flea-host networks from four biogeographic realms and asked whether the species composition of (a) host spectra and (b) flea assemblages is similar between functionally similar flea and host species, respectively. Analogously to testing for phylogenetic signal, we applied Mantel tests to investigate the correlation between flea or host functional distances calculated from functional dendrograms and dissimilarities in sets of interacting partners. In all realm-specific networks, functionally similar fleas tended to exploit similar hosts often belonging to the same genus, whereas functionally similar hosts tended to harbour similar fleas, again often belonging to the same genus. The strength of realm-specific functional signals and the frequency of detecting a significant functional signal in the regional networks differed between realms. The frequency of detecting a significant functional signal in the regional networks correlated positively with the network size for fleas and with the number of hosts in a network for hosts. A functional signal in the regional networks was more frequently found for hosts than for fleas. We discuss the mechanisms behind the functional signal in both fleas and their hosts, relate geographic functional signal patterns to the historic biogeography of fleas and conclude that functional signals in the species composition of host spectra for fleas and of flea assemblages for hosts result from the interplay of evolutionary and ecological processes., (© 2024. The Author(s).)

Background: Ectoparasites of dogs and cats are implicated to be responsible for life-threatening anaemia, allergic dermatitis and pruritic and non-pruritic skin disorders. In Ethiopia, few studies have been conducted on the arthropods of dogs and cats., Objectives: In order to shed light on some of these aspects, a survey was conducted to investigate the presence of ectoparasites in dogs and cats living in sympatry in the urban and rural areas of Gamo Zone, Ethiopia., Methods: A total of 297 dogs and 110 cats were examined for ectoparasites, and questionnaires were employed to obtain information concerning owner's knowledge about arthropods and vector-borne diseases (VBDs)., Results: The overall prevalence of ticks, fleas and lice in dogs was 36.7%, 69.7% and 4.7%, respectively. Similarly, on cats, an overall prevalence of 2.7% ticks and 21.8% fleas was recorded. On dogs, fleas (Ctenocephalides felis 69.4%, Echidnophaga gallinacea 1.3%, Ctenocephalides canis 1.0% and Pulex irritans 0.3%), ticks (Amblyomma variegatum 22.9%, Rhipicephalus sanguineus 14.1%, Haemaphysalis leachi 8.8%, Rhipicephalus praetextatus 4.0% and Rhipicephalus pulchellus 3.4%) and lice (Heterodoxus spiniger 4.0% and Trichodectes canis 0.7%) were identified. Likewise, on cats, fleas (C. felis [15.5%] and E. gallinacea [7.3%]) and ticks (H. leachi [2.7%]) were identified. The abundance of C. felis was significantly higher (p < 0.001) on dogs, whereas in cats, the abundance of E. gallinacea was significantly higher (p = 0.002) than the other ectoparasites. On dogs, a significantly higher prevalence of Rh. sanguineus was recorded in urban areas (<0.001) and on dogs which live in indoor environments (p = 0.003) than on dogs which live in other environments. On the other hand, the prevalence of A. variegatum in rural areas and midland agroecology was significantly higher (p < 0.001). The prevalence of H. leachi was significantly higher in midland (p < 0.001) and on adult dogs (p = 0.001). Overall, fleas were more prevalent in rural (p = 0.029) than in urban areas, and female dogs were with higher infestation than the male (p = 0.047) dogs; C. felis was prevalent in female (p = 0.038) dogs than males. Overall, 88.3% owners in the study area had no knowledge about ectoparasites and VBDs of dogs and cats. Majority of the owners (64.8%) attest that they had never visited veterinary clinics., Conclusions: In conclusion, the data presented in the present study provide additional knowledge on the importance of ectoparasites of dogs and cats and are believed to contribute in awareness creation and strengthening of veterinary services of dogs and cats of the study area., (© 2024 The Authors. Veterinary Medicine and Science published by John Wiley & Sons Ltd.)

From ancient times to the present, parasites and the diseases they transmit have jeopardized the health and wellbeing of working and companion canines worldwide. Many common pests that afflict dogs can be classified as ectoparasites (e.g., fleas, ticks, lice), which serve as vectors of pathogens transmitted as the organism feeds or defecates; or endoparasites (e. g, helminths, protozoa), which can cause slowly progressive subclinical canine diseases as well as acute illnesses associated with high morbidity and mortality rates. Safe, effective antiparasitic prophylaxis in dogs remains a topic of major interest to both veterinarians and their clients, especially with respect to the prevention of canine heartworm infection and flea or tick infestation. Many compounders, especially those whose pharmacy includes a retail component, counsel veterinarians and pet owners about preparations and commercially available medications that prevent or treat parasitic infestations and provide assistance in obtaining those therapies. To support such efforts, this article provides information about single agents and combination-drug products prophylactic against common canine parasites, emerging resistance to those medications, and the toxic effects that such treatments can engender in some canine breeds., (Copyright© by International Journal of Pharmaceutical Compounding, Inc.)

Background: Fleas are ectoparasitic insects with holometabolous development. It has a hematophagous habit with mouthparts adapted to sting and suck its hosts. There are about 3000 species in the world, ∼61 in Brazil, and 19 in Rio Grande do Sul state. The objective of the research is to catalog the diversity of fleas recorded in the state, their respective hosts, and endosymbionts. Materials and Methods: To this end, a search was carried out in the scientific literature, from articles, books, to abstracts submitted to congresses. Results: The 19 species of fleas occurring in Rio Grande do Sul are divided into 7 families and 10 genera. These ectoparasites, in addition to being found in the environment, were associated with 10 different families of hosts in Rio Grande do Sul, and on the endosymbiont, agents found associated with fleas, there were 7 different species. The main agents researched in the state are Rickettsia spp. and Bartonella spp. The relationships between parasites, hosts, environment, and etiological agents present different scenarios, whether anthropized or conserved, but unknown. Sometimes, this overlap, a factor that aggravates the possibility of spillovers, either from cosmopolitan fleas in these conserved areas, or from their endosymbionts. Conclusion: Thus, it is important to characterize the environment so that the complexities of each location are known for the adoption of environmental and public health policies in each case. The challenges are extensive, but necessary in view of the One Health perspective.

As ectoparasites and efficient vectors of pathogens fleas constitute a source of nuisance for animals as well as a major issue for public health in Algeria. In this study, a molecular survey has been conducted to investigate the presence of pathogens in fleas infesting domestic and wild carnivores in the central north and eastern north and south of Algeria. The molecular screening that targeted Acanthocheilonema reconditum, Bartonella spp.,and Dipylidium caninum, was supplemented by a comprehensive analysis of risk factors related to flea-borne pathogens, drawing data from all documentation across multiple languages and sources from Morocco, Algeria, and Tunisia. In the current study, several Bartonella spp. 56/430 (13.02%) and Dipylidium caninum 3/430 (0.7%) were identified. The sequencing results revealed 5/23 (21.74%) B. clarridgeiae, 3/23 (13.04%) B. henselae, and 3/23 (13.04%) B. vinsonii. The two haplotypes, H1 and H2, of D. caninum were identified for the first time in North Africa. The results of the Artificial Neural Network risk analyses unveiled that the prevalence of pathogens and the presence of host generalist fleas as well as the vectorial competence are the most determinant risk factors of flea-borne diseases in Maghreb., Competing Interests: Declaration of competing interest The authors declare that there is no conflict of interest., (Copyright © 2023. Published by Elsevier Ltd.)

In recent years, plague has re-emerged in several countries around the world and remains endemic in some regions. In a natural environment and in contact with rodents and their fleas, stray carnivores are most at risk of catching the disease and maintaining the spread of the bacillus. The present study aimed to demonstrate the presence or absence of Yersinia pestis in stray dogs and cats in the Algiers region by molecular methods and thus determine their role in epidemiology of this disease. Molecular research of Yersinia pestis has also been conducted on fleas from these carnivores. Preliminary identification of ectoparasites to genus and species level was performed. Real-time polymerase chain reaction targeting Yersinia pestis pla gene was used to survey the plague agent in fleas and carnivores captured as stray animals in Algiers (Algeria). Positive qPCR results were tested by PCR sequencing using glpD gene. Among 327 fleas captured from 107 dogs and 365 fleas from 140 cats, prevalence of Ctenocephalides felis was higher in cats (86,96%), whereas that of Ctenocephalides canis and Xenopsylla cheopis were higher in dogs (90,57% and 92,63%, respectively). While internal and external PCR positive controls were positive, none of the 107 dogs spleens and 140 cats spleens and none of the 256 analyzed fleas were positive for Y. pestis . These results suggested that stray cats and dogs are unlikely sources of plague in Algeria, contrary to what has been reported in other plague-endemic countries. This observation illustrates that the plague epidemiological chain varies from one region to another., Competing Interests: The authors declare that there is no conflict of interests regarding the publication of this paper.

We studied the relationships between functional alpha and beta diversities of fleas and their small mammalian hosts in 4 biogeographic realms (the Afrotropics, the Nearctic, the Neotropics and the Palearctic), considering 3 components of alpha diversity (functional richness, divergence and regularity). We asked whether (a) flea alpha and beta diversities are driven by host alpha and beta diversities; (b) the variation in the off-host environment affects variation in flea alpha and beta diversities; and (c) the pattern of the relationship between flea and host alpha or beta diversities differs between geographic realms. We analysed alpha diversity using modified phylogenetic generalized least squares and beta diversity using modified phylogenetic generalized dissimilarity modelling. In all realms, flea functional richness and regularity increased with an increase in host functional richness and regularity, respectively, whereas flea functional divergence correlated positively with host functional divergence in the Nearctic only. Environmental effects on the components of flea alpha diversity were found only in the Holarctic realms. Host functional beta diversity was invariantly the best predictor of flea functional beta diversity in all realms, whereas the effects of environmental variables on flea functional beta diversity were much weaker and differed between realms. We conclude that flea functional diversity is mostly driven by host functional diversity, whereas the environmental effects on flea functional diversity vary (a) geographically and (b) between components of functional alpha diversity.

Background: Fleas are important hematophagous insects, infesting mammals and birds with a worldwide distribution. Fleas of medical importance have been reported from various carnivores worldwide, such as felids, canids, or mustelids. Romania hosts a wide carnivore diversity, but very little is known about flea species that parasitize these animals in Romania. This study aimed to provide a better understanding of the fleas' diversity and their distribution in a relatively large and diverse number of wild carnivore hosts from Romania., Methods: From 2013 to 2021, 282 carcasses of wild carnivores from different locations in Romania were collected and examined for the presence of ectoparasites. All collected fleas were morphologically identified using specific keys and descriptions. An analysis of the co-occurrence networks was performed., Results: A total of 11 flea species were identified: Pulex irritans (41.09%), Paraceras melis (20.11%), Ctenocephalides felis (7.33%), Ctenocephalides canis (7.83%), Monopsyllus sciurorum (11.11%), Chaetopsylla trichosa (21.96%), Chaetopsylla homoea (5.5%), Chaetopsylla tuberculaticeps (100%), Chaetopsylla rothschildi (13.33%), Chaetopsylla sp. (14.34%), Chaetopsylla globiceps (5.12%), Echidnophaga gallinacea (10%). The statistical analyses showed a significant difference between the infestation of Martes foina with females being more frequently infected than males (66% versus 33%). Paraceras melis infesting Meles meles had a significantly higher prevalence in female badgers than in males (× 2 = 7.7977, P < 0.01) and higher intensities of infestations in males than in females (t = 1.871, P < 0.05)., Conclusions: This is the first large-scale study investigating the distribution and diversity of flea species infesting wild carnivores in Romania. Three flea species were identified for the first time in Romania (E. gallinacea, C. homoea, and C. tuberculaticeps)., (© 2024. The Author(s).)

Introduction: To date, a total of 2574 validated flea species have been discovered. Vermipsyllidae is a family of fleas that comprises at least eight species. Vermipsylla is a genus of the family Vermipsyllidae within the order Siphonaptera of fleas. Here a novel Vermipsylla species was described, and rickettsial agent was also detected in it., Methods: A total of 128 fleas were collected directly from 260 pastured sheep in China. Of these, eight representative fleas (four males and four females) were identified by key morphological features. Meanwhile, 120 flea DNAs, including six flea samples for molecular taxonomy, were subjected to Rickettsia spp. DNA detection. The molecular identity of fleas was determined by amplification and sequenmce analysis of four genetic markers (the 28S rDNA genes, the 18S rDNA genes, the mitochondrial cytochrome c oxidase subunit I and subunit II). In addition, five Rickettsia-specific gene fragments were used to identify the species of the rickettsial agents. The amplified products were sequenced and phylogenetically analyzed., Results: The morphological characteristics of the flea species identified in this study were similar to Vermipsylla alakurt, but presented difference in hair number of the metepimeron, the third tergum, the genitals and the tibiae of hind leg. The 18S rDNA, 28S rDNA and COII genetic markers from fleas showed the highest identity to those of V. alakurt, shared 98.45% (954/969), 95.81% (892/931) and 85.86% (571/665) similarities, respectively. However, the COI sequence showed the highest identity to that of Dorcadia ioffi with 88.48% (576/651) similarity. Rickettsia raoutii tested positive in 14.17% (17/120) flea DNA samples., Conclusion: Our study reports the detection of R. raoultii in V. alakurt-like fleas infesting sheep in China., (© 2024. The Author(s).)

Background: External parasites, particularly ticks and fleas, are among the most common problems affecting dogs. Chemical medicines are commonly used to prevent and eliminate such external parasites, but their improper use can cause adverse reactions, and the toxins they contain may remain in the environment., Objectives: The objective of this study was to investigate the in vitro efficacy of Zanthoxylum limonella , citronella, clove, peppermint, and ginger essential oils against dog ticks and fleas and to test the sensitivity of dogs' skin to these essential oils., Methods: The five essential oils were tested for in vitro efficacy against ticks and fleas, and the two most effective essential oils were then tested on the dogs' skin., Results: The results revealed that these five essential oils at 16% concentrations effectively inhibited the spawning of female engorged ticks. In addition, all five essential oils had a strong ability to kill tick larvae at concentrations of 2% upward. Furthermore, 4% concentrations of the five essential oils quickly eliminated fleas, especially clove oil, which killed 100% of fleas within 1 h. A 50%, 90%, and 99% lethal concentration (LC 50 , LC 90 , and LC 99 ) for the essential oils on tick larvae in 24 h were found to be low values. LC 50 , LC 90 , and LC 99 for the essential oils on flea in 1 h was lowest values. Clove oil at 16% concentration was the most satisfactory essential oil for application on dogs' skin, with a low percentage of adverse effects., Conclusions: This study confirmed the effectiveness of essential oils for practical use as tick and flea repellents and eliminators. Essential-oil-based pharmaceutical can replace chemical pesticides and provide benefits for both consumers and the environment., Competing Interests: The authors declare no conflicts of interest., (© 2024 The Korean Society of Veterinary Science.)

The present study aimed to identify tick and flea species infesting captive tapirs (Tapirus terrestris and Tapirus kabomani) in the Brazilian Amazon. Ectoparasites were collected from tapirs chemically restrained in Zoo-botanical Parks, breeding facilities, conservationists and, environmental compensation areas in the states of Amapá, Amazonas, and Pará. After collection, the tick and flea specimens were placed in plastic pots containing isopropanol and identified according to dichotomous keys. Ectoparasite infestations were observed in 55% (18/33) tapirs, of which 61% (11/18) were single infestations with ticks or fleas, and 39% (7/18) were mixed infestations with different species of ticks and/or fleas. In total, 227 ticks (15 larvae, 107 nymphs, 38 females and 67 males) and 14 fleas (eight females and six males) were collected, identifying four tick species (Amblyomma cajennense sensu stricto , Amblyomma naponense, Amblyomma oblongoguttatum, and Amblyomma pacae) and three flea species and/or subspecies (Ctenocephalides felis felis, Rhopalopsyllus australis australis, and Tunga penetrans). In conclusion, infestations with Ixodidae ticks and Rhopalopsyllidae, Pulicidae and Tungidae fleas were found in captive tapirs in the Brazilian Amazon, and A. cajennense s.s. was the most frequent species. Additionally, the present study reports new associations between A. pacae and R. a. australis with T. terrestris and between A. cajennense s.s. with T. kabomani., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023. Published by Elsevier GmbH.)

We investigated the presence and potential causes of sex bias in ectoparasite infestations in the yellow-necked mouse Apodemus flavicollis. We compared the natural tick and flea burdens of male and female mice in a temperate beech forest and assessed whether the observed differences were driven by host sex or body mass. We found that males were more heavily infested by ticks compared to female mice. However, this difference was driven by host body mass, and not sex itself. Host body mass positively correlated with flea loads, but there was no evidence of sex bias in flea abundance. In addition, the abundance of both ticks and fleas infesting yellow-necked mice changed over time, both seasonally (month to month) and annually (year to year). Our results underscore the importance of the sexual size dimorphism and the parasite taxon as the primary factors that influence the occurrence of sex-biased parasitism in small mammals., (© 2023. The Author(s).)

We investigated compositional and phylogenetic nestedness in the host assemblages of 26 host-generalist fleas across regions within the Palearctic. We asked the following questions: (i) are host assemblages exploited by a flea species compositionally or phylogenetically nested (=C-nested and P-nested, respectively) across regions?; (ii) if yes, what are the processes that generate nestedness, and does phylogenetic nestedness follow the same processes as compositional nestedness?; and (iii) are the biological traits of a flea species associated with its host assemblages' degree of nestedness? Nestedness was calculated for matrices with rows ordered either by decreasing region area (=a-matrices) or increasing distance from the centre of a flea's geographic range (d-matrices). Significant C-nestedness was found in either a- (three fleas) or d-matrices (three fleas) or both (10 fleas). Significant P-nestedness was detected in either a- (three fleas) or d-matrices (four fleas) or both (two fleas). In some but not other species, P-nestedness followed C-nestedness. The probability of C-nestedness to be significant, as well as its degree for d-matrices, was associated with a flea's morphoecological traits, whereas this was not the case for either a-matrices or the P-nestedness for either type of ordered matrices. We conclude that compositional, but not phylogenetic, nestedness is (i) generated by similar mechanisms in many flea species and (ii) may be simultaneously driven by different mechanisms in the same flea. In contrast, mechanisms promoting phylogenetic nestedness differ between flea species and seem to act separately., (Copyright © 2023 Australian Society for Parasitology. Published by Elsevier Ltd. All rights reserved.)

Host specificity of fleas affects their biodiversity that plays a major role in determining the potential transmission routes by pathogens through vertebrate hosts, including humans. In the Biogeographic Andean region, numerous systematic and ecological studies have been conducted, revealing a high diversity of flea taxa of mammals and the presence of pathogenic organisms transmitted by fleas; however, the degree of preference with which each flea species associates with a mammal host remains poorly understood in this region. Herein, host specificity in mammal fleas from the Andean region was analysed. We employed the number of host species for each flea species and the index of host specificity S TD *. Following the literature, 144 species and 13 subspecies of fleas (31 genera and 10 families) have been described in the Andean biogeographic region; 76 taxa are endemic to this region. To carry out the analyses of host specificity, we considered 1759 records of fleas collected from 124 species and 59 genera of wild and domestic mammals, mostly rodent species (85.9%). Our results indicate that typical Andean fleas are genus or family host specific (mostly S TD * less than 3.0). More diverse mammal hosts are parasitized by more diverse flea genera and families and these hosts are phylogenetically related. Otherwise, these hosts are associated with different flea lineages, suggesting the interaction of ecological and evolutionary mechanisms (host-switching, ecological adaptations and co-evolutionary alternation). The fields of disease ecology and One Health are considering the host specificity of arthropod vectors as an important point to understand the mechanisms of emergence and re-emergence of diseases. Our results allow us to estimate the risk of diseases involving fleas in the Andean region., (© 2023 Royal Entomological Society.)

Fleas are important ectoparasites and vectors associated with a wide range of pathogenic diseases, posing threats to public health concerns, especially cat fleas that spread worldwide. Understanding the microbial components is essential due to cat fleas are capable of transmitting pathogens to humans, causing diseases like plague and murine typhus. In the present study, metagenomic next-generation sequencing was applied to obtain the complete microbiota and related functions in the gut of Ctenocephalides felis. A total of 1,870 species was taxonomically recognized including 1,407 bacteria, 365 eukaryotes, 69 viruses, and 29 archaea. Proteobacteria was the dominant phylum among the six samples. Pathogens Rickettsia felis, Acinetobacter baumannii, Coxiella burnetii, and Anaplasma phagocytophilum were taxonomically identified and had high abundances in all samples. The resistance gene MexD was predominant in microbial communities of all cat fleas. We also performed epidemiological surveys of pathogens R. felis, A. baumannii, C. burnetii, and A. phagocytophilum among 165 cat fleas collected from seven provinces in China, while only the DNAs of R. felis (38/165, 23.03%) and C. burnetii (2/165, 1.21%) were obtained. The data provide new insight and understanding of flea intestinal microbiota and support novel information for preventing and controlling fleas and their transmitted diseases., Competing Interests: Declaration of Competing Interest The authors report no declarations of interest., (Copyright © 2023 Elsevier B.V. All rights reserved.)

The role of red fox as host for a wide range of parasites, particularly fleas and other arthropods causing vector-borne diseases, in combination with its capability to adapt to anthropized environments, makes this wild canid an epidemiologically remarkable species at the wildlife-domestic-human interface, especially in the present time of rise of emerging and re-emerging diseases. This study evaluated the prevalence and parasite intensity of fleas in 88 foxes from Murcia Region (Southeastern Spain) and determined the geographic distribution of areas with the highest potential risk of flea presence. Pulex irritans, Ctenocephalides felis, Spilopsyllus cuniculi and Nosopsyllus fasciatus were identified. The overall prevalence was 76.13%. This is the first time that N. fasciatus has been reported in foxes from Murcia Region. The predictive model established a certain pattern to determine the areas with the highest risk of acquiring fleas. Positive correlation of daily potential evapotranspiration (ET 0 ) in winter and the opposite effect occurring for ET 0 in summer were obtained, as well as positive correlations for mean daily temperature (T mean ) in summer and mean precipitation (P mean ) in winter and summer. The model was also found positively correlated in the forest habitat ecotone areas and the anthropized areas., (© 2022 The Authors. Medical and Veterinary Entomology published by John Wiley & Sons Ltd on behalf of Royal Entomological Society.)

Background: The Silk Road connected the East and West for over 1500 years. Countries in Central Asia are valuable in addressing the hypothesis that parasites on domestic animals were introduced along the Silk Road. Adult fleas are obligate parasites, having worldwide distribution. In dogs, Ctenocephalides canis, C. felis and C. orientis are the most common species identified. The distribution of the Oriental cat flea, C. orientis, is restricted to southeast Asia. The purpose of this study was to determine the diversity of dog fleas from Uzbekistan, a country in Central Asia, with particular reference to C. orientis., Methods: Fleas were collected from 77 dogs from 5 locations in Uzbekistan. The cox1 gene sequences from Ctenocephalides spp. were compared to global collection of Ctenocephalides cox1 haplotypes. Landmark-based geometric morphometrics have been applied to the head and curvature to compare C. canis and C. canis using canonical variate analysis and discriminant function analysis., Results: Overall, 199 fleas were collected and identified as C. canis (n = 115, 58%), C. orientis (n = 53, 27%) and Pulex irritans (n = 22, 11%). None of the fleas were C. felis. All Ctenocephalides spp. fleas were subject to cox1 amplification and 95% (166/175) yielded DNA sequence. There were 25 cox1 haplotypes; 14 (22/25, 88%) were C. canis cox1 haplotypes and 3 (3/25, 12%) were C. orientis cox1 haplotypes. Molecular analysis confirmed the absence of C. felis. Four (4/22) and one (1/3) cox1 haplotypes were identical to cox1 haplotypes belonging to C. canis and C. orientis cox1 haplotypes identified elsewhere, respectively. Overall morphometric analysis confirmed significant differences between the head shape of C. canis and C. orientis and improved four-fivefold the species identification compared to traditional morphological key., Conclusion: We report for the first time the presence of C. orientis in Uzbekistan. Differentiation of C. orientis from C. canis and C. felis remains difficult in regions where these species coexist. Studies in Central and Southeast Asia should confirm species identity using cox1 locus to enable retracing of the distribution of the Ctenocephalides in Asia. The presence of C. orientis suggests that this species may have been introduced from the east along the ancient Silk Road., (© 2022. The Author(s).)

Rickettsia sp. and Bartonella sp. were detected in ectoparasites of free-roaming domestic cats (Felis catus) from a trap-neuter-release program in central Oklahoma during January and February 2020. We used polymerase chain reaction and sequencing to identify fleas containing DNA of five different pathogens: Rickettsia felis (84%), 'Candidatus R. andeanae' (8%), Bartonella henselae (32%), Bartonella clarridgeiae (36%), and Bartonella sp. (8%). Co-infections with R. felis with three Bartonella species were identified. One tick was positive for R. felis, one flea was positive for 'Candidatus R. andeanae' and one ear mite was positive for a Bartonella species. These results highlight the need for more focus on free-roaming domestic cats and their ectoparasites in the Great Plains region., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Background: Fleas (Insecta: Siphonaptera) are obligatory hematophagous ectoparasites of humans and animals and serve as vectors of many disease-causing agents. Despite past and current research efforts on fleas due to their medical and veterinary importance, correct identification and robust phylogenetic analysis of these ectoparasites have often proved challenging., Methods: We decoded the complete mitochondrial (mt) genome of the human flea Pulex irritans and nearly complete mt genome of the dog flea Ctenocephalides canis, and subsequently used this information to reconstruct the phylogeny of fleas among Endopterygota insects., Results: The complete mt genome of P. irritans was 20,337 bp, whereas the clearly sequenced coding region of the C. canis mt genome was 15,609 bp. Both mt genomes were found to contain 37 genes, including 13 protein-coding genes, 22 transfer RNA genes and two ribosomal RNA genes. The coding region of the C. canis mt genome was only 93.5% identical to that of the cat flea C. felis, unequivocally confirming that they are distinct species. Our phylogenomic analyses of the mt genomes showed a sister relationship between the order Siphonaptera and orders Diptera + Mecoptera + Megaloptera + Neuroptera and positively support the hypothesis that the fleas in the order Siphonaptera are monophyletic., Conclusions: Our results demonstrate that the mt genomes of P. irritans and C. canis are different. The phylogenetic tree shows that fleas are monophyletic and strongly support an order-level objective. These mt genomes provide novel molecular markers for studying the taxonomy and phylogeny of fleas in the future., (© 2022. The Author(s).)

Microbial metabarcoding is a common method to study the biology of blood-feeding arthropods and identify patterns of potential pathogen transmission. Before DNA extraction, specimens are often surface washed to remove environmental contaminants. While surface washing is common, its effects on microbial diversity remain unclear. We characterized the microbiome of the flea species Ceratophyllus idius, an avian ectoparasite, and a potential vector of pathogens, using high-throughput 16S rRNA sequencing. Half of the nests from which fleas were collected were subjected to an environmental manipulation in which nesting materials were periodically replaced. In a crossed study design we surface washed half of the flea samples from each environmental condition to produce 4 experimental conditions. Environmental manipulations resulted in significant differences in the diversity and structure of the flea microbiome, but these differences were unapparent when specimens were surface washed. Furthermore, differential abundance testing of the experimental groups revealed that surface washing predominantly affected the abundance of bacterial groups that are characterized as environmental contaminants. These findings suggest that environmental changes primarily affect the surface microbiome of arthropods and that surface washing is a useful tool to reduce the footprint of the external microbiome on analysis., (© American Society of Parasitologists 2022.)

We investigated the performance trade-offs of fleas (Siphonaptera) while adapting to a novel host using two host generalists (Xenopsylla conformis and Xenopsylla ramesis) and one host specialist (Parapulex chephrenis) maintained on their principal hosts (Meriones crassus for Xenopsylla and Acomys cahirinus for P. chephrenis). We asked whether, over generations, (i) a host generalist may become a specialist by evolving the ability to exploit a novel host and losing the ability to exploit an original host and (ii) a host specialist can become a generalist by evolving the ability to exploit a novel host without losing the ability to exploit an original host. We established an experimental line of each species on a novel host (Acomys russatus for Xenopsylla and M. crassus for P. chephrenis) and maintained this line on this host during 23 generations. We compared reproductive performance of progenitors of each line and their descendants when they exploited either original or novel host in terms of egg number and size, hatching success, offspring production, and offspring size. We found changes in performance over generations in female offspring size only. Xenopsylla conformis demonstrated a tendency to become a host specialist (increased performance on the novel host with a concomitant decreased performance on the original host), whereas P. chephrenis demonstrated a tendency to become a host generalist (increased performance on the novel host without a concomitant decreased performance on the original host). We conclude that the probability of generalist to specialist transition, and vice versa, is context-dependent and varies between species., (© 2021 Institute of Zoology, Chinese Academy of Sciences.)

Fleas are important in public health due to their role as parasites and vectors of pathogens, including Rickettsia. The aim of this study was to evaluate the diversity, abundance and prevalence of fleas and the presence of Rickettsia in the trifinio of north-east Argentina. Fleas from household and synanthropic animals were obtained from urban and periurban areas. They were taxonomically identified and samples of 227 fleas in 86 pools were analysed by polymerase chain reaction targeting the gltA and ompB genes of Rickettsia spp. The study revealed that Ctenocephalides felis felis was dominant on dogs, cats and opossums, with higher prevalence in the periurban area. The Shannon-Wiener and Morisita-Horn indices expressed differences in the diversity and similarity values of the absolute abundances of the species between the areas compared. DNA amplifications revealed 30.8% C. f. felis pools positive for Rickettsia spp. Phylogenetic analysis showed that the haplotype obtained was identical to Rickettsia asembonensis from Peru and Brazil. This is the first detection in Argentina of R. asembonensis that infects C. f. felis, and we emphasize the importance of conducting research from a 'One Health' perspective on the role of opossums and rodents in the integration of the transmission cycles of rickettsial bacteria., (© 2021 Royal Entomological Society.)

An assemblage of species in a locality comprises two components, namely (i) species that are present (realised diversity) and (ii) species from the regional pool that may potentially inhabit this locality due to suitable ecological conditions, but that are absent (dark diversity). We investigated factors affecting the dark diversity of component communities of fleas parasitic on small mammals in the northern Palearctic at two scales. First, we considered the dark diversity of flea assemblages of the same host (for 13 host species) across regions and tested for the effects of environmental factors and the number of available host species on the dark diversity of within-region flea assemblages. Second, we considered the dark diversity of fleas across host species within a region (for 20 regions) and asked whether within-host dark diversity is associated with host phylogeny and/or traits. We found that the dark diversity of flea assemblages harboured by small mammals varied substantially (i) within the same host species across space (in 12 of 13 host species) and (ii) between host species within a region (in eight of 20 regions). The size of the dark diversity of flea assemblages of the same host across regions was generally affected by environmental factors (mainly by the amount of green vegetation), whereas the size of the dark diversity of flea assemblages of a host species within a region was affected by host traits (mainly by the degree of host sociality and the structure of its shelter and, to a lesser degree, by its geographic range size) but was not associated with host phylogenetic affinities. We conclude that application of the dark diversity concept to parasite communities across space or hosts allows a better understanding of the factors affecting the species richness and composition of these communities., (Copyright © 2021 Australian Society for Parasitology. Published by Elsevier Ltd. All rights reserved.)

In Argentina, quantitative information on the composition and structure of assemblages of arthropod parasites in Xenarthra is scarce. The aim of this study was to describe and compare the community of arthropod parasites of Chaetophractus villosus and Zaedyus pichiy in the Argentinean Patagonia. A total of 1300 ectoparasites (1224 fleas and 76 ticks) were collected from both host species. Seven different species were found, namely Phthiropsylla agenoris, Malacopsylla grossiventris, Hectopsylla broscus, Tunga penetrans, Tunga perforans (Siphonaptera), Amblyomma pseudoconcolor and Amblyomma auricularium s.l. (Ixodida). Four species were present in both host armadillos (P. agenoris, M. grossiventris, H. broscus and A. pseudoconcolor). Phthiropsylla agenoris was the most prevalent and abundant ectoparasite showing significant differences in prevalences, mean intensities and mean abundance. Malacopsylla grossiventris only showed significant differences in mean intensity. The structure and composition of the ectoparasite assemblage and the high values of ectoparasites aggregation recorded in the Patagonian armadillos strongly suggest that these associations are stable throughout their geographical distribution., (Copyright © 2021. Published by Elsevier B.V.)

The beta-diversity of interactions between communities does not necessarily correspond to the differences related to their species composition because interactions show greater variability than species co-occurrence. Additionally, the structure of species interaction networks can itself vary over spatial gradients, thereby adding constraints on the dissimilarity of communities in space. We used published data on the parasitism interaction between fleas and small mammals in 51 regions of the Palearctic to investigate how beta-diversity of networks and phylogenetic diversity are related. The networks could be separated in groups based on the metrics that best described the differences between them, and these groups were also geographically structured. We also found that each network beta-diversity index relates in a particular way with phylogenetically community dissimilarity, reinforcing that some of these indexes have a strong phylogenetic component. Our results clarify important aspects of the biogeography of hosts and parasites communities in Eurasia, while suggesting that networks beta-diversity and phylogenetic dissimilarity interact with the environment in different ways.

Background: The study objective was to examine cat owner ectoparasiticide purchases in the United States and estimate the impact of purchase gaps on timely ectoparasite protection administration. These purchase gaps lead to periods of time when cats are unprotected from ectoparasites., Methods: Ectoparasiticide purchase transactions for individual cats from 671 U.S. veterinary clinics from January 1, 2017 through June 30, 2019 were evaluated to determine time "gaps" between doses of ectoparasiticides purchased in a defined 12-month period. Ectoparasiticides examined were topically applied products that contained fluralaner, fipronil/(S)-methoprene/pyriproxyfen, imidacloprid/pyriproxyfen or selamectin as active ingredients. The duration of protection following administration of one dose was 8-12 weeks for the fluralaner-containing product and one month for the other products., Results: Ectoparasiticide purchase records were obtained from 114,853 cat owners and analysis found that most owners bought ≤ 6 months of protection during the year, with 61-75% (depending on the product) purchasing just 1-3 months of protection. The size of the average purchase gap was determined for all dose combinations out to 12 months of protection (5-7 doses for fluralaner and 12 doses for the other three products dosed monthly. The largest gaps occurred between the first and second doses and the second and third doses. Average purchase gaps for the four different products between doses 1 and 2 ranged from 11.2 to 13.9 weeks and between doses 2 and 3 ranged from 7.7 to 12.2 weeks. The fraction of purchases separated by gaps and the average length of the gap tended to decrease with increasing number of doses purchased. Owners purchasing the 8 to 12-week duration product containing fluralaner provided ectoparasite protection ("doses plus gap period") for a larger proportion of each 2-dose period compared with owners purchasing products administered monthly., Conclusions: When cat owners purchase flea and tick medication, gaps between subsequent purchases reduces the proportion of time ectoparasite protection can be provided. The duration of the gap between doses has an impact on the effectiveness of flea/tick medication because it inserts a period without flea and tick protection between doses of flea and tick medication. The gaps between purchases were shorter and the period of ectoparasite protection was larger for owners purchasing a 12-week product than for owners purchasing a monthly product.

In total, 341 fleas belonging to 16 species were collected from 78 host mammals belonging to 10 species in Panamá from 2010 to 2016. The cat flea, Ctenocephalides felis (Bouché) predominated on domestic dogs and was also recorded from domestic cats, the raccoon, Procyon lotor (Linnaeus) and the common opossum, Didelphis marsupialis Linnaeus. The largest number of flea species (7) was recorded from D. marsupialis and the most common flea on that host was the ctenophthalmid, Adoratopsylla intermedia copha Jordan. One Oriental rat flea, Xenopsylla cheopis (Rothschild), was collected from D. marsupialis. Native rodents were parasitized by indigenous ceratophyllid, rhopalopsyllid, and stephanocircid fleas. The Mexican deermouse, Peromyscus mexicanus (Saussure), was parasitized by six species of ceratophyllids belonging to the mostly Central American genera, Baculomeris, Jellisonia, Kohlsia and Plusaetis. The long-tailed singing mouse, Scotinomys xerampelinus (Bangs), was parasitized by Plocopsylla scotinomi Tipton and Méndez, the only species of stephanocircid flea known from Central America. Twenty-six pools of extracted flea DNA representing 5 flea species (C. felis, Pulex echidnophagoides (Wagner), Pulex simulans Baker, A. intermedia copha, and P. scotinomi) and 79 individual fleas were all real-time polymerase chain reaction negative for Rickettsia felis, Rickettsia typhi, and Bartonella henselae., (© The Author(s) 2020. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

A new ctenophthalmid flea species, Ctenophthalmus (Ctenophthalmus) yesarii n. sp., is described and illustrated. This new species belonging to the fransmiti group is most closely related to Ctenophthalmus (Ctenophthalmus) fransmiti Suciu. Specimens of Ct. yesarii n. sp. were collected from the eastern broad-toothed field mouse, Apodemus mystacinus (Danford & Alston), in Balıkesir (Edremit district) province of Turkey. The number of Ctenophthalmus taxa known from Turkey now tallies 41 taxa (27 species and 14 subspecies).

Members of the flea family Pulicidae have been the focus of many studies due to their significance as diseases vectors of medical and veterinary importance and their cosmopolitan distribution. They often exhibit variation in morphological features that can make correct species identification and management challenging. This may also apply to Xenopsylla brasiliensis (Baker, 1904), an important plague vector. In the current study, we aimed to provide genetic tools for reliable species identification using a DNA barcoding approach. A total of 73 flea specimens was collected from a native host (Namaqua rock mouse, Micaelamys namaquensis) in South Africa and identified morphologically. In addition, we took measurements of 7 morphological characteristics. Subsequently, we successfully generated barcodes of the mitochondrial cytochrome c oxidase subunit I (COI) gene for X. brasiliensis. We validated this approach by comparing our data to COI sequences from Rwandan X. brasiliensis. While sequences from both regions suggested a close relationship between the 2 X. brasiliensis populations, both haplotype and nucleotide diversity were substantially larger for the South African specimens. This may be attributed to human-assisted spread, differences in habitat, and/or host species sampled and merits further study in the future., (© American Society of Parasitologists 2021.)

We studied the success of fleas, Synosternus cleopatrae and Xenopsylla ramesis, in switching to a novel host by establishing experimental lines maintained on different hosts for 18 generations. Fleas fed on principal (P-line) or novel hosts, either sympatric with (S-line) or allopatric to (A-line) a flea and its principal host, then we assessed their reproductive performance via the number and size of eggs. We compared reproductive performance between hosts within a line and between lines within a host asking: (a) whether fleas adapt to a novel host species after multiple generations; (b) if yes, whether the pattern of adaptation differs between novel host species sympatric with or allopatric to a flea and its principal host; and (c) adaptation to a novel host is accompanied with a loss of success in exploitation of an original host. Fleas from the S- and A-lines increased their egg production on a novel host (except X. ramesis from the S-line). S. cleopatrae from the S-line but not the A-line increased egg size on a novel host, whereas X. ramesis from the A-line but not the S-line produced larger eggs from a novel host. We found no indication of a loss of reproductive performance on the original host while adapting to a novel host. We conclude that fleas are able to switch rapidly to a new host with the pattern of a switch to either sympatric or an allopatric host depending on the identities of both flea and host species.

The causal chain of parasite-host-environment interactions, the so-called 'dual parasite environment', makes studying parasites more complicated than other wild organisms. A sample of 65 282 fleas taken from 336 different locations were analysed for changes in the distribution, diversity and compensation of flea communities found on small mammals along an elevational diversity gradient ranging from the Pannonian Plain to the base of the Carpathian summits. The fleas were divided into four groups, which were derived from changes in abundance and occurrence determined from cluster analysis. They are (1) flea species whose range seems unrelated to any change in elevation; (2) species that avoid high altitudes; (3) a group that can be subdivided into two types: (i) host-specific fleas and (ii) mountains species and (4) species opting for high altitudes on the gradient or preferring lower to middle elevations below 1000 m. Our study showed a unimodal pattern of flea diversity along the elevational gradient. It indicated that seasonality significantly conditions changes in biodiversity and patterns of spatial change along the elevational gradient, with specific flea species influenced by their host, while the impact of environmental conditions is more pronounced in opportunistic flea species.

The Neotropical region shows a great diversity of fleas, comprising more than 50 genera. The importance of the study of fleas is linked to their potential role as disease vectors. The aim of this study is to investigate the presence of Rickettsia spp. and Bartonella spp. in Neotropical fleas collected from wild rodents in Southern Brazil. From 350 rodents captured, 30 were parasitized by fleas. A total of 61 fleas belonging to two genera and six different species were collected (Craneopsylla minerva minerva, Polygenis occidentalis occidentalis, Polygenis platensis, Polygenis pradoi, Polygenis rimatus, and Polygenis roberti roberti). In 13 % of fleas of three different species (C. minerva, P. platensis, and P. pradoi) Rickettsia sp. DNA was found. Phylogenetic analysis of concatenated sequences of gltA, htrA, and ompA genes showed that Rickettsia sp. found in rodent fleas (referred as strain Taim) grouped together with Spotted Fever Group Rickettsia. In reference to Bartonella spp., five genotypes were identified in seven fleas of two species (C. minerva and P. platensis) and in five rodent spleens. Also, 207 frozen samples of wild rodents were screened for these pathogens: while none was positive for Rickettsia spp.; five rodent spleens were PCR-positive for Bartonella spp.. Herein, we show the detection of potential novel variants of Bartonella sp. and Rickettsia sp. in fleas collected of wild rodents from Southern Brazil. Further studies are needed to fully characterize these microorganisms, as well as to improve the knowledge on the potential role of Neotropical flea species as diseases vectors., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Echidnophaga gallinacea is the sticktight flea of chickens. It causes dermatitis and ulcers in the skin and carries some disease-causing agents such as Rickettsia and Bartonella. This study was conducted to detect the infection rate and elucidate the molecular characterization of E. gallinacea in chickens from El-Dabaa City, Matrouh Governorate, Egypt. The fleas were collected from infected chickens and identified morphologically. The internal transcribed spacer-1 (ITS-1) gene PCR method was used for molecular characterization. Based on the morphology, the collected fleas were confirmed as E. gallinacea. The overall infection rate was 5%, with 4.5% in female and 10% in male chickens. ITS-1 PCR revealed a specific band of 488 bp. The ITS-1 gene sequence from Egypt occurred in the same phylogenetic clade as that from Cameroon, with a percentage identity of 98.47%., (Copyright © 2020 Elsevier B.V. All rights reserved.)