Résumé of the Siphonaptera (Insecta) of the world

Brazilian fleas (Hexapoda: Siphonaptera): diversity, host associations, and new records on small mammals from the Atlantic Rainforest, including Rickettsia screening

BACKGROUND

Insects belonging to the Siphonaptera order are obligatory ectoparasites of vertebrates, including humans. Their life cycle is marked by holometabolous development, and adults are adapted to have a bloodmeal out of their hosts. The objective of this study is to review the families occurring in Brazil with their species and report new records from fleas collected in an Atlantic Rainforest preserved area, including Rickettsia sp. monitoring.

METHODS

Literature research was carried out, including journal articles and books available in scientific databases. The sample collection took place at Legado das Águas-Reserva Votorantim private reserve, where wild rodents, marsupials, and bats were captured and inspected for the presence of fleas. The fleas were identified, and their genetic material was extracted and subjected to two polymerase chain reactions (PCRs): an endogenous control to validate the extraction and a Rickettsia screening.

RESULTS

A total of 8 families were reviewed, resulting in 63 valid species that interact with a wide range of hosts. Among the collected fleas, 7 species were identified as interacting with 19 different host genera belonging to the Rodentia, Didelphimorphia, and Chiroptera orders. We highlight the presence of 2 new locality records and 15 new host interactions. Of the collected fleas, 105 specimens were tested individually for Rickettsia bacteria, but none showed expected amplicons for the bacterium.

CONCLUSIONS

This study provides an extensive revision of the Siphonaptera order present in Brazil with new insights, since the last robust revision made was from 2000, along with new information regarding host association and locality based on field collections conducted by the authors, which helps understanding the host-parasite interaction and encourages new studies.

Phylogeny and divergence time estimation of the subfamily Amphipsyllinae based on the Frontopsylla diqingensis mitogenome

Fleas are primarily parasites of small mammals and serve as essential vectors of the transmission of plague. The subfamily Amphipsyllinae (Siphonaptera: Leptopsyllidae) consists of 182 species across 13 genera, widely distributed worldwide. Only two species of Amphipsyllinae have been sequenced for complete mitogenomes to date. It hinders the taxonomy and evolutionary history studies of fleas. In this study, we first sequenced the Frontopsylla diqingensis mitogenome and performed comparative mitogenomic analyses with the two other species (Frontopsylla spadix and Paradoxopsyllus custodis) in Amphipsyllinae available in the NCBI database. The evolutionary process of Amphipsyllinae was comprehensively analyzed in terms of nucleotide composition, codon usage, nucleotide diversity, tRNA secondary structure, nucleotide skew, phylogeny tree, and divergence time. Nucleotide diversity and tRNAs of three species of fleas of Amphipsyllinae have differences among different species. The effective number of codon (ENC)-plot, neutrality curve, PR2, and correspondence analysis (COA) showed that the codon preference of Amphipsyllinae was influenced mainly by natural selection. For phylogenetic trees and divergence time of the order Siphonaptera, our results showed two concatenated data matrices, namely, PCG: (((Ceratophyllidae + Leptopsyllidae) + ((Vermipsyllidae + Hystrichopsyllidae) + Ctenophthalmidae)) + (Pulicidae + Pygiopsyllidae)); PCGRNA: ((((Ceratophyllidae + Leptopsyllidae) + ((Vermipsyllidae + Hystrichopsyllidae) + Ctenophthalmidae)) + Pulicidae) + Pygiopsyllidae). We concluded that P. custodis and Macrostylophora euteles from GenBank are the same species by phylogenetic trees and sequence alignment, and supported the monophyly of Amphipsyllinae. Amphipsyllinae diverged in the Cenozoic, approximately 73.37-40.32 million years ago (Mya). The majority of the species within the intraordinal divergence into extant lineages occurred after the K-Pg boundary. The common ancestor of the extant order Siphonaptera diverged during the Cretaceous. Our findings supported those of Zhu et al. (1). This study provides new insights into the evolutionary history and taxonomy of the order Siphonaptera.

Attempted Transmission of Marburg Virus by Bat-Associated Fleas Thaumapsylla breviceps breviceps (Ischnopsyllidae: Thaumapsyllinae) to the Egyptian Rousette Bat (Rousettus aegyptiacus)

Egyptian rousette bats (ERBs) are implicated as reservoir hosts for Marburg virus (MARV), but natural mechanisms involved in maintenance of MARV in ERB populations remain undefined. A number of hematophagous ectoparasites, including fleas, parasitize bats. Subcutaneous (SC) inoculation of ERBs with MARV consistently results in viremia, suggesting that infectious MARV could be ingested by blood-sucking ectoparasites during feeding. In our study, MARV RNA was detected in fleas that took a blood meal during feeding on viremic bats on days 3, 7, and 11 after SC inoculation. Virus concentration in individual ectoparasites was consistent with detectable levels of viremia in the blood of infected host bats. There was neither seroconversion nor viremia in control bats kept in close contact with MARV-infected bats infested with fleas for up to 40 days post-exposure. In fleas inoculated intracoelomically, MARV was detected up to 14 days after intracoelomic (IC) inoculation, but the virus concentration was lower than that delivered in the inoculum. All bats that had been infested with inoculated, viremic fleas remained virologically and serologically negative up to 38 days after infestation. Of 493 fleas collected from a wild ERB colony in Matlapitsi Cave, South Africa, where the enzootic transmission of MARV occurs, all tested negative for MARV RNA. While our findings seem to demonstrate that bat fleas lack vectorial capacity to transmit MARV biologically, their role in mechanical transmission should not be discounted. Regular blood-feeds, intra- and interhost mobility, direct feeding on blood vessels resulting in venous damage, and roosting behaviour of ERBs provide a potential physical bridge for MARV dissemination in densely populated cave-dwelling bats by fleas. The virus transfer might take place through inoculation of skin, mucosal membranes, and wounds when contaminated fleas are squashed during auto- and allogrooming, eating, biting, or fighting.

The complete mitochondrial genome of the rodent flea Nosopsyllus laeviceps: genome description, comparative analysis, and phylogenetic implications

BACKGROUND

Fleas are one of the most common and pervasive ectoparasites worldwide, comprising at least 2500 valid species. They are vectors of several disease-causing agents, such as Yersinia pestis. Despite their significance, however, the molecular genetics, biology, and phylogenetics of fleas remain poorly understood.

METHODS

We sequenced, assembled, and annotated the complete mitochondrial (mt) genome of the rodent flea Nosopsyllus laeviceps using next-generation sequencing technology. Then we combined the new mitogenome generated here with mt genomic data available for 23 other flea species to perform comparative mitogenomics, nucleotide diversity, and evolutionary rate analysis. Subsequently, the phylogenetic relationship within the order Siphonaptera was explored using the Bayesian inference (BI) and maximum likelihood (ML) methods based on concentrated data for 13 mt protein-coding genes.

RESULTS

The complete mt genome of the rodent flea N. laeviceps was 16,533 base pairs (bp) in a circular DNA molecule, containing 37 typical genes (13 protein-coding genes, 22 transfer RNA [tRNA] genes, and two ribosomal RNA [rRNA] genes) with one large non-coding region (NCR). Comparative analysis among the order Siphonaptera showed a stable gene order with no gene arrangement, and high AT content (76.71-83.21%) with an apparent negative AT and GC skew except in three fleas Aviostivalius klossi bispiniformis, Leptopsylla segnis, and Neopsylla specialis. Moreover, we found robust evidence that the cytochrome c oxidase subunit 1 (cox1) gene was the most conserved protein-coding gene (Pi = 0.15, non-synonymous/synonymous [Ka/Ks] ratio = 0.13) of fleas. Phylogenomic analysis conducted using two methods revealed different topologies, but both results strongly indicated that (i) the families Ceratophyllidae and Leptopsyllidae were paraphyletic and were the closest to each other, and (ii) the family Ctenophthalmidae was paraphyletic.

CONCLUSIONS

In this study, we obtained a high-quality mt genome of the rodent flea N. laeviceps and performed comparative mitogenomics and phylogeny of the order Siphonaptera using the mt database. The results will enrich the mt genome data for fleas, lay a foundation for the phylogenetic analysis of fleas, and promote the evolutionary analysis of Siphonaptera.

Molecular Identification, Multigenic Characterization and Phylogenetic Analysis of Ctenocephalides Canis Fleas from Humans and Domestic Animals in Iran

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.

Fleas (Siphonaptera, Latreille, 1825) from Rio Grande do Sul State, Brazil: Species Diversity, Hosts, and One Health Approach

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.

Immune Reactions of Vector Insects to Parasites and Pathogens

This overview initially describes insect immune reactions and then brings together present knowledge of the interactions of vector insects with their invading parasites and pathogens. It is a way of introducing this Special Issue with subsequent papers presenting the latest details of these interactions in each particular group of vectors. Hopefully, this paper will fill a void in the literature since brief descriptions of vector immunity have now been brought together in one publication and could form a starting point for those interested and new to this important area. Descriptions are given on the immune reactions of mosquitoes, blackflies, sandflies, tsetse flies, lice, fleas and triatomine bugs. Cellular and humoral defences are described separately but emphasis is made on the co-operation of these processes in the completed immune response. The paper also emphasises the need for great care in extracting haemocytes for subsequent study as appreciation of their fragile nature is often overlooked with the non-sterile media, smearing techniques and excessive centrifugation sometimes used. The potential vital role of eicosanoids in the instigation of many of the immune reactions described is also discussed. Finally, the priming of the immune system, mainly in mosquitoes, is considered and one possible mechanism is presented.

Analysis of complete mitogenomes and phylogenetic relationships of Frontopsylla spadix and Neopsylla specialis

Fleas represent a group of paramount medical significance, subsisting on blood and acting as vectors for an array of naturally occurring diseases. These pathogens constitute essential elements within the plague biome, exerting deleterious effects on both human and livestock health. In this study, we successfully assembled and sequenced the whole mitochondrial genome of Frontopsylla spadix and Neopsylla specialis using long-range PCR and next-generation sequencing technologies. The mitogenomes of F. spadix and N. specialis both have 37 genes with full lengths of 15,085 bp and 16,820 bp, respectively. The topology of the phylogenetic tree elucidates that species F. spadix is clustered in a branch alongside other members of the family Leptopsyllidae, whereas species N. specialis is a sister taxon to Dorcadia ioffi and Hystrichopsylla weida qinlingensis. It also suggests that Pulicidae form a monophyletic clade, Ctenopthalmidae, Hystrichopsyllidae, Vermipsyllidae form a sister group to Ceratophyllidae/Leptopsyllidae group. The mitochondrial genomes of F. spadix and N. specialis were sequenced for the first time, which will contribute to a more comprehensive phylogenetic analysis of the Siphonaptera order. The foundation for subsequent systematic studies, and molecular biology of fleas was established.

Seasonality and other risk factors for fleas infestations in domestic dogs and cats

Fleas in the genus Ctenocephalides are the most clinically important parasitic arthropods of dogs and cats worldwide yet risk factors that might increase the risk of infestation in small animals remains unclear. Here we developed a supervised text mining approach analysing key aspects of flea epidemiology using electronic health records from domestic cats and dogs seen at a sentinel network of 191 voluntary veterinary practices across Great Britain between March 2014 and July 2020. Our methods identified fleas as likely to have been present during 22,276 of 1,902,016 cat consultations (1.17%) and 12,168 of 4,844,850 dog consultations (0.25%). Multivariable logistic regression modelling found that animals originating from areas of least deprivation were associated with 50% reductions in odds of veterinary-recorded flea infestation compared to the most deprived regions in England. Age of the animal was significantly associated with flea presentation in both cats and dogs, with cases peaking before animals reached 12 months. Cases were recorded through each study years, peaking between July and October, with fluctuations between each year. Our findings can be used towards healthcare messaging for veterinary practitioners and owners.

First case report of hospital staff infestation with cat flea (Ctenocephalides felis) in Iran

Background

Cat fleas (Ctenocephalides felis) are the most common ectoparasites of domestic cats and dogs worldwide. They can parasitize humans in many regions of the globe. Hospital infestation with fleas has not been reported in Iran, and the number of reported cases in the world is very low.

Case presentation

Here we report and describe a hospital infestation with cat fleas in a number of health-care service personnel and nurses, which led to the development of skin lesions and severe itching.

Conclusion

Diagnosing the parasite, removing it, and good health and medical management lead to satisfactory outcomes.

Fleas (Siphonaptera) From the Puma, Puma concolor (Carnivora: Felidae), A Rangewide Review and New Records from Utah and Texas, USA

Fleas have rarely been reported from the puma, Puma concolor (Linnaeus, 1771), despite its vast geographic range, its breadth of habitat use, and its diverse diet, all of which bring it into contact with many other species of mammals and potentially their fleas. We review the reported occurrence of 8 species of fleas from pumas, 7 of these species being from wild hosts and 1 species from a host in captivity, and we correct the mistaken report of 1 other flea species from the puma. We present 10 new records of 4 species of fleas from the puma in Utah and Texas. 2 of these flea species, Cediopsylla inaequalis inaequalis (Baker, 1895) and Odontopsyllus dentatus (Baker, 1904), represent new host records, and 1 species, Chaetopsylla setosa Rothschild, 1906, is a new state record for Utah as well as being 1 of the 2 southernmost known localities for this species. At least 7 of the 9 flea species now known from free-ranging pumas are species that are acquired by pumas from their prey. Pumas may be primary hosts of 2 flea species, but even these fleas may be from prey. Some of the flea species that parasitize pumas transmit sylvatic plague, and, since pumas are highly vagile and are known to become infected with plague, they may spread the disease through their dispersal of infected fleas. Pumas and their fleas also may be involved in the ecology of several other bacterial zoonoses, which are discussed.

The complete mitochondrial genome of Xenopsylla cheopis (Siphonaptera: Pulicidae)

Xenopsylla cheopis, also called oriental rat flea, is an ectoparasite as well as disease vector for murine typhus and bubonic plague. In the study, the whole mitochondrial genome of X. cheopis was sequenced and assembled, which is the second report of mitochondrial genome in the family Pulicidae and the sixth mitochondrial genome in the order Siphonaptera (fleas). The mitochondrial genome is 18,902 bp in length, consisting of 40% A, 44% T, 6% G, and 10% C. Phylogenetic analysis of all available mitochondrial genomes from Siphonaptera indicated that X. cheopis clustered with Ctenocephalides felis since both species belonged to the family Pulicidae. The complete mitochondrial genome of X. cheopis could serve as useful genetic data for investigating the genetic relationship of fleas.

Molecular detection of Rickettsia in fleas from micromammals in Chile

Background

Rickettsial diseases are considered important in public health due to their dispersal capacity determined by the particular characteristics of their reservoirs and/or vectors. Among the latter, fleas play an important role, since the vast majority of species parasitize wild and invasive rodents, so their detection is relevant to be able to monitor potential emerging diseases. The aim of this study was to detect, characterize, and compare Rickettsia spp. from the fleas of micromammals in areas with different human population densities in Chile.

Methods

The presence of Rickettsia spp. was evaluated by standard polymerase chain reaction (PCR) and sequencing in 1315 fleas collected from 1512 micromammals in 29 locations, with different human population densities in Chile. A generalized linear model (GLM) was used to identify the variables that may explain Rickettsia prevalence in fleas.

Results

DNA of Rickettsia spp. was identified in 13.2% (174 of 1315) of fleas tested. Fifteen flea species were found to be Rickettsia-positive. The prevalence of Rickettsia spp. was higher in winter, semi-arid region and natural areas, and the infection levels in fleas varied between species of flea. The prevalence of Rickettsia among flea species ranged between 0–35.1%. Areas of lower human density showed the highest prevalence of Rickettsia. The phylogenetic tree showed two well-differentiated clades with Rickettsia bellii positioned as basal in one clade. The second clade was subdivided into two subclades of species related to Rickettsia of the spotted fever group.

Conclusions

To our knowledge, this is the first report of the occurrence and molecular characterization of Rickettsia spp. in 15 flea species of micromammals in Chile. In this study, fleas were detected carrying Rickettsia DNA with zoonotic potential, mainly in villages and natural areas of Chile. Considering that there are differences in the prevalence of Rickettsia in fleas associated with different factors, more investigations are needed to further understand the ecology of Rickettsia in fleas and their implications for human health.

High frequency of knockdown resistance mutations in the para gene of cat flea (Ctenocephalides felis) samples collected from goats

Fleas are ectoparasites of mammals and birds. In livestock such as sheep and goat, flea bites cause many clinical signs. Several types of insecticides including pyrethroids are used to struggle against fleas. The widespread use of these insecticides causes an increase in the number of resistant individuals in flea populations. T929V and L1014F mutations corresponding to pyrethroid resistance have been found in the para gene of cat fleas. We aimed to investigate T929V and L1014F mutations in flea samples (n:162) collected from goats in seven different farms where cypermethrin, a synthetic pyrethroid, had been used intensively. To achieve this aim, collected flea samples were morphologically identified under a stereo microscope and DNA isolation was conducted by HotSHOT method. Later, a bi-PASA targeting the para gene was applied to identify both mutations in corresponding samples. According to the results obtained, all fleas were Ctenocephalides felis. Frequencies of T929V and L1014F mutations in fleas were 92.6% (150/162) and 95.7% (155/162), respectively. In conclusion, the frequency of mutations related to pyrethroid resistance was very high in the fleas collected from all the farms and it was thought that the high frequency of these mutations can be attributed to intensive use of pyrethroids.

Who Bites Me? A Tentative Discriminative Key to Diagnose Hematophagous Ectoparasites Biting Using Clinical Manifestations

Arthropod blood feeders are vectors of several human pathogenic agents, including viruses (e.g., yellow fever, chikungunya, dengue fever), parasites (e.g., malaria, leishmaniasis, lymphatic filariasis), or bacteria (e.g., plague). Besides their role as a vector of pathogens, their biting activities cause a nuisance to humans. Herein, we document clinical symptoms associated with the biting of ten clusters of hematophagous arthropods, including mosquitoes, biting midges and sandflies, lice, ticks, tsetse flies, blackflies, horse flies, fleas, triatomine and bed bugs. Within the framework of clinical history and entomo-epidemiological information, we propose a tentative discriminative key that can be helpful for practicing physicians in identifying hematophagous arthropods biting humans and delivering treatment for the associated clinical disorders.

Flea surveillance on wild mammals in northern region of Xinjiang, northwestern China

Flea distribution in northern region of Xinjiang Uygur Autonomous Region (XUAR) and fluctuations of the annual fleas index in Alataw Pass were investigated. During a 4-year (2015-2018) study, 5789 fleas were collected directly from 15 mammals at eight counties in northern XUAR of northwestern China. Nineteen flea species, belonging to sixteen genera and seven families, were further confirmed by four genetic markers (18S rDNA, 28S rDNA, COI and COII) after morphological observation. Pulex irritans and Paraceras crispum parasitizing Asian badgers (Meles leucurus) were recorded for the first time. In addition, the fluctuations of the annual fleas index in Alataw Pass were surveyed. Xenopsylla gerbilli minax, Xenopsylla conformis conformis and Nosopsyllus laeviceps laeviceps were highly detected in the warm season while Paradoxopsyllus repandus, Ctenophthalmus dolichus dolichus and Coptopsylla lamellifer ardua were only found in the cold season. These findings extend our knowledge of flea species, distribution and annual fluctuations especially in China-Kazakhstan border.

Origin, evolution, phylogeny and taxonomy of Pulex irritans

The human flea Pulex irritans Linnaeus, 1758 (Siphonaptera: Pulicidae) is one of the most studied species together with the cat flea Ctenocephalides felis Bouché, 1835, because they have a cosmopolitan distribution and are closely related to humans. The present study aimed to carry out a comparative morphometric and molecular study of two different populations of P. irritans (Spain and Argentina). Accordingly, internal transcribed spacer (ITS)1 and ITS2 of rDNA and the partial cytochrome c oxidase subunit 1 (cox1) and cytochrome b (cytb) mtDNA genes of these taxa were sequenced. Furthermore, the taxonomy, origin, evolution and phylogeny of P. irritans was assessed. The morphometric data obtained did not show significant differences between P. irritans specimens from Spain and Argentina, even when these two populations were collected from different hosts; however, there was a considerable degree of molecular divergence between both populations based on nuclear and mitochondrial markers. Thus, it is proposed that P. irritans, in contrast with other generalist fleas, maintains a certain degree of morphological similarity, at least between Western Palearctic and Neotropical areas. Furthermore, two well defined geographical genetic lineages within the P. irritans species are indicated, suggesting the existence of two cryptic species that could be discriminated by a polymerase chain reaction-linked restriction fragment length polymorphism.

Fleas associated with sigmodontine rodents and marsupials from the Paranaense Forest in Northeastern Argentina

Fleas from the Paranaense Forest in northeastern Argentina are studied. Herein we provided a list of specimens identified, which includes host species and geographical distribution for each taxa, as well as some comments on the morphology, distribution and epidemiological importance when available. The following eight species and subspecies of fleas belonging to four families were identified: Ctenocephalides felis felis (Pulicidae), Craneopsylla minerva minerva (Stephanocircidae), Polygenis (Polygenis) platensis, Polygenis (Polygenis) roberti beebei, Polygenis (Neopolygenis) pradoi, Polygenis (Neopolygenis) pygaerus (Rhopalopsyllidae), Adoratopsylla (Adoratopsylla) antiquorum antiquorum, and Adoratopsylla (Tritopsylla) intermedia intermedia (Ctenophthalmidae). The results obtained increase to eleven the known diversity of fleas in the Argentinean Paranaense Forest area. Seven new flea-host associations are reported for the first time. In addition, all the species and subspecies are mentioned for the first time for the province of Misiones. Besides, the results contribute to the knowledge of mammal ectoparasites and to their biodiversity of the Province, necessary to a better understanding of their role as parasites themselves and vectors of zoonotic importance.

Bats, Bat Flies, and Fungi: A Case of Hyperparasitism

Bats are parasitized by numerous lineages of arthropods, of which bat flies (Diptera, Nycteribiidae and Streblidae) are the most conspicuous. Bat flies themselves can be parasitized by Laboulbeniales, fungal biotrophs of arthropods. This is known as hyperparasitism, a severely understudied phenomenon. Three genera of Laboulbeniales occur on bat flies: Arthrorhynchus on Nycteribiidae, Gloeandromyces and Nycteromyces on Streblidae. In this review we introduce the parasitic partners in this tripartite system and discuss their diversity, ecology, and specificity patterns, alongside some important life history traits. Furthermore, we cover recent advances in the study of the associations between bat flies and Laboulbeniales, which were neglected for decades. Among the most immediate needs for further studies are detailed tripartite field surveys. The vermin only teaze and pinch Their foes superior by an inch So, naturalists observe, a flea Has smaller fleas that on him prey; And these have smaller still to bite 'em, And so proceed ad infinitum. Jonathan Swift (On Poetry: A Rhapsody, 1733).

Siphonaptera of Canada

There are currently 154 species of fleas recorded in Canada in four superfamilies and seven families. Only two species have been added to the list since the previous summary by Holland (1979) one of which is unlikely to be established in Canada. There have been a number of significant nomenclatural changes since then most notable of which is the split of the Hystrichopsyllidae into two families Hystrichopsyllidae and Ctenophthalmidae. An additional 23 species may eventually be recorded based on presence of suitable hosts and proximity to known distributions. Six species are introduced and one species is adventive. Although total diversity is reasonably well known there are numerous gaps in distribution of fleas throughout the country. Barcode Index Numbers are available for only 22 species of fleas collected in Canada.

Morphological, biometrical and molecular characterization of Archaeopsylla erinacei (Bouché, 1835)

In the present work, we carried out a morphological, biometrical and molecular study of the species Archaeopsylla erinacei (Bouché, 1835) and their subspecies: Archaeopsylla erinacei erinacei (Bouché, 1835) and Archaeopsylla erinacei maura (Jordan & Rothschild, 1912) isolated from hedgehogs (Erinaceus europaeus) from different geographical regions (Seville and Corse). We have found morphological differences in females of A. erinacei from the same geographical origin that did not correspond with molecular differences. We suggest that some morphological characters traditionally used to discriminate females of both subspecies should be revised as well as we set the total length of the spermatheca as a valid criterion in order to discriminate between both subspecies. The Internal Transcribed Spacers 1 and 2 (ITS1, ITS2) and partial 18S rRNA gene, and partial cytochrome c-oxidase 1 (cox1) and cytochrome b (cytb) mtDNA gene sequences were determined to clarify the taxonomic status of these taxa and to assess intra-specific and intra-population similarity. In addition, a phylogenetic analysis with other species of fleas using Bayesian and Maximum Likelihood analysis was performed. All molecular markers used, except 18S, showed molecular differences between populations corresponding with geographical origins. Thus, based on the phylogenetic and molecular study of two nuclear markers (ITS1, ITS2) and two mitochondrial markers (cox1 and cytb), as well as concatenated sequences of both subspecies, we reported the existence of two geographical genetic lineages in A. erinacei corresponding with two different subspecies: A. e. erinacei (Corse, France) and A. e. maura (Seville, Spain), that could be discriminated by polymerase chain reaction-linked random-fragment-length polymorphism.

Comparison of Flea (Siphonaptera) Burdens on the Endangered San Joaquin Kit Fox (Vulpes macrotis mutica (Carnivora, Canidae)) Inhabiting Urban and Nonurban Environments in Central Valley, California

The San Joaquin kit fox (Vulpes macrotis mutica Merriam (Carnivora, Canidae)) is an endangered small carnivore endemic to the San Joaquin Valley of California. Commercial and agricultural land expansion has contributed to the species' decline and invasion of more cosmopolitan species, providing means for potential ecological shifts in disease vector and host species. Fleas are common ectoparasites that can serve as important indicators of cross-species interactions and disease risk. We compared flea load and species composition on kit foxes inhabiting urban and nonurban habitats to determine how urbanization affects flea diversity and potential disease spillover from co-occurring species. We identified Echidnophaga gallinacea (Westwood) (Siphonaptera, Pulicidae) and Pulex spp. (L.) in both urban and nonurban populations, and Ctenocephalides felis (Bouche) (Siphonaptera, Pulicidae) only in the urban population. Flea load scores differed significantly across capture sites and with respect to concomitant sarcoptic mange infestation in the urban population, with milder flea infestations more typical of healthy foxes. All observed flea species are known vectors for pathogens that have been detected in mesocarnivores. Further examination of kit fox fleas and their associated pathogens will help to direct conservation and disease preventive measures for both wildlife and humans in the region.

The Fleas (Siphonaptera) in Iran: Diversity, Host Range, and Medical Importance

BACKGROUND

Flea-borne diseases have a wide distribution in the world. Studies on the identity, abundance, distribution and seasonality of the potential vectors of pathogenic agents (e.g. Yersinia pestis, Francisella tularensis, and Rickettsia felis) are necessary tools for controlling and preventing such diseases outbreaks. The improvements of diagnostic tools are partly responsible for an easier detection of otherwise unnoticed agents in the ectoparasitic fauna and as such a good taxonomical knowledge of the potential vectors is crucial. The aims of this study were to make an exhaustive inventory of the literature on the fleas (Siphonaptera) and range of associated hosts in Iran, present their known distribution, and discuss their medical importance.

METHODOLOGY/PRINCIPAL FINDINGS

The data were obtained by an extensive literature review related to medically significant fleas in Iran published before 31st August 2016. The flea-host specificity was then determined using a family and subfamily-oriented criteria to further realize and quantify the shared and exclusive vertebrate hosts of fleas among Iran fleas. The locations sampled and reported in the literature were primarily from human habitation, livestock farms, poultry, and rodents' burrows of the 31 provinces of the country. The flea fauna were dominated by seven families, namely the Ceratophyllidae, Leptopsyllidae, Pulicidae, Ctenophthalmidae, Coptopsyllidae, Ischnopsyllidae and Vermipsyllidae. The hosts associated with Iran fleas ranged from the small and large mammals to the birds. Pulicidae were associated with 73% (56/77) of identified host species. Flea-host association analysis indicates that rodents are the common hosts of 5 flea families but some sampling bias results in the reduced number of bird host sampled. Analyses of flea-host relationships at the subfamily level showed that most vertebrates hosted fleas belgonging to 3 subfamilies namely Xenopsyllinae (n = 43), Ctenophthalminae (n = 20) and Amphipsyllinae (n = 17). Meriones persicus was infested by 11 flea subfamilies in the arid, rocky, mountainous regions and Xenopsyllinae were hosted by at least 43 mammal species. These findings place the Persian jird (M. persicus) and the Xenopsyllinae as the major vertebrate and vector hosts of flea-borne diseases in Iran including Yersinia pestis, the etiological agent of plague. We found records of at least seven vector-borne pathogenic agents that can potentially be transmitted by the 117 flea species (or subspecies) of Iran.

CONCLUSIONS/SIGNIFICANCE

Herein, we performed a thorough inventary of the flea species and their associated hosts, their medical importance and geographic distribution throughout Iran. This exercise allowed assessing the diversity of flea species with the potential flea-borne agents transmission risk in the country by arranging published data on flea-host associations. This information is a first step for issuing public health policies and rodent-flea control campaigns in Iran as well as those interested in the ecology/epidemiology of flea-borne disease.

Checklist dos Siphonaptera do Estado do Mato Grosso do Sul

RESUMO As pulgas são insetos hematófagos na fase adulta e que atuam como agentes infestantes ou como vetores de patógenos. Seus hospedeiros são animais endotérmicos, essencialmente mamíferos e, predominantemente roedores. A sifonapterofauna do estado do Mato Grosso do Sul representa 15,9% (10/63) da brasileira, sendo muito pouco conhecida quando comparada com outros estados em número de espécies ou gêneros. Considerando as espécies que poderiam ocorrer em continuidade geográfica de estados, países e/ou biomas, as ainda não conhecidas ou cosmopolitas, uma riqueza mais expressiva é estimada. Uma espécie é endêmica no estado.

Insecticide Resistance in Fleas

Fleas are the major ectoparasite of cats, dogs, and rodents worldwide and potential vectors of animal diseases. In the past two decades the majority of new control treatments have been either topically applied or orally administered to the host. Most reports concerning the development of insecticide resistance deal with the cat flea, Ctenocephalides felis felis. Historically, insecticide resistance has developed to many of the insecticides used to control fleas in the environment including carbamates, organophosphates, and pyrethroids. Product failures have been reported with some of the new topical treatments, but actual resistance has not yet been demonstrated. Failures have often been attributed to operational factors such as failure to adequately treat the pet and follow label directions. With the addition of so many new chemistries additional monitoring of flea populations is needed.

Molecular study of Stenoponia tripectinata tripectinata (Siphonaptera: Ctenophthalmidae: Stenoponiinae) from the Canary Islands: taxonomy and phylogeny

In the present work, we carried out a comparative molecular study of Stenoponia tripectinata tripectinata isolated from Mus musculus from the Canary Islands, Spain. The Internal Transcribed Spacers 1 and 2 (ITS1, ITS2) and 18S ribosomal RNA partial gene and cytochrome c-oxidase 1 (cox1) mitochondrial DNA partial gene sequences of this subspecies were determined to clarify the taxonomic status of this subspecies and to assess inter-population variation and inter-specific sequence differences. In addition, we have carried out a comparative phylogenetic study with other species of fleas using Bayesian, Maximum Parsimony, Maximum Likelihood and Neighbor-Joining analysis. A geographical signal was detected between the cox1 partial gene sequences of S. t. tripectinata isolated from M. musculus from different islands and those isolated from Apodemus sylvaticus from the Iberian Peninsula. Our results assess the monophyletic origin of Stenoponiinae and a different genetic lineage from Ctenophthalmidae. Thus, the elevation of subfamily Stenoponiinae to family level (Stenoponiidae) is suggested.

A New Genus of Fleas with Associated Microorganisms in Dominican Amber

A flea preserved in Dominican amber is described as Atopopsyllus cionus, n. gen., n. sp. (Atopopsyllini n. tribe, Spilopsyllinae, Pulicidae). The male specimen has two unique characters that have not been noted in previous extant or extinct fleas, thus warranting its tribal status. These characters are five-segmented maxillary palps and cerci-like organs on abdominal tergite X. Additional characters are the absence of ctenidia, very small eyes, a lanceolate terminal segment of the maxillary palps, legs with six notches on the dorsal margin of the tibiae, five pairs of lateral plantar bristles on the distitarsomeres, and nearly straight ungues with a wide space between the basal lobe and tarsal claw. Trypanosomes and coccobacilli in the rectum and coccobacilli on the tip of the epipharynx of the fossil are depicted and briefly characterized.

Notes on the genus Tunga (Siphonaptera: Tungidae) II--neosomes, morphology, classification, and other taxonomic notes

This review focuses on the neosomes, morphology, and taxonomy of adult species of the genus Tunga, complementing the previously published data on the phylogeny, ecology, and pathogenic role. Neosomes are structures formed after penetration of adult females into the skin of hosts resulting in significant enlargement, being the most characteristic and most frequently observed form in hosts. Neosomes can be differentiated by shape, measurements, and sites of attachment to principal hosts. The taxonomic value and morphometric data of the most widely used characteristics to separate species – such as frontal curvature, head chaetotaxy, preoral internal sclerotization, ventral and dorsal genal lobes, eyes, maxillary palps, fusion of pronotum and mesonotum, metacoxae, metatarsi chaetotaxy, spermatheca (females), manubrium, basimere, telomere, and phallosome (males) – are comparatively analyzed. The sexes, individual variations, undescribed species, higher taxa, as well as a proposal for division of the genus into two subgenera (Tunga and Brevidigita) are presented (as previously given by Wang). A key for females, males, and gravid females (neosomes) also is included for identifying the 13 known species. Data on host specificity and geographical distribution may also support the identification of Tunga species because some sand fleas and their hosts may have co-evolved.

Neosomes of tungid fleas on wild and domestic animals

Tunga is the most specialized genus among the Siphonaptera because adult females penetrate into the skin of their hosts and, after mating and fertilization, undergo hypertrophy, forming an enlarged structure known as the neosome. In humans and other warm-blooded animals, neosomes cause tungiasis, which arises due to the action of opportunistic agents. Although its effects on humans and domestic animals are well described in the literature, little is known about the impact of tungiasis on wild animals. This review focuses on the morphology, taxonomy, geographical distribution, hosts, prevalence, sites of attachment, and impact of tungid neosomes on wild and domestic animals. Because neosomes are the most characteristic form of the genus Tunga and also the form most frequently found in hosts, they are here differentiated and illustrated to aid in the identification of the 13 currently known species. Perspectives for future studies regarding the possibility of discovering other sand flea species, adaptation to new hosts, and the transfer of tungids between hosts in natural and modified habitats are also presented.

Tungiasis: a neglected epidermal parasitic skin disease of marginalized populations--a call for global science and policy

Tungiasis (sand flea disease) is an ectoparasitic skin disease caused by the female sand flea/jigger flea (Tunga penetrans). As poverty is the major driving force of the disease, it can be called as a poverty-associated plague. It is one of the emerging neglected diseases in Latin America, Caribbean, sub-Saharan Africa, and India. The aim of the present scrutiny was to assess the public health impact of tungiasis, associated risk factors, and emerging opportunities to prevent and control tungiasis. Searches of PubMed, Google Scholar, and online search engines (Google, AOL, and Yahoo) using keywords "parasitic skin disease," "tungiasis," "sand flea," " tungiasis-associated risk factors," "tungiasis prevention and control," and their synonyms were used as a source of references. Searches were made without time limitations. Of 167 potential articles identified by these criteria, 51 appropriate were selected for review. Tungiasis is widespread in the resource-constrained settings of low-income economies. In the tropics, it is highly prevalent among the impoverished populations, but the associated risk factors are often poorly identified and remain uncontrolled. Though it is a self-limiting disease with considerable morbidity, the parasite may cause subsequent secondary morbidity through life-threatening complications and infections like cellulitis, tetanus, and death. However, the direct and indirect sociocultural, economic, and health impact of tungiasis is often undervalued and misunderstood. A systematic assessment on disease burden is still dearth and deficient. Over the decades, tungiasis has been largely neglected by the scientific community, policy makers, and healthcare stakeholders. In the endemic regions, even tungiasis is not listed for the disease control priorities in the regional, national, and international agenda. The majority of the epidermal parasitic skin diseases particularly tungiasis needs a sustainable global scientific research and control policy. This urges intensive efforts to develop a road map that delivers a clear vision towards zero new infection by designing low-cost prevention and control strategies. Besides, there is an urgency to develop culturally appropriate communication techniques and workable collaboration on a global scale by bringing all the stakeholders of endemic countries.

Patterns of diversity and abundance of fleas and mites in the Neotropics: host-related, parasite-related and environment-related factors

The effects of host-related, parasite-related and environmental factors on the diversity and abundance of two ectoparasite taxa, fleas (Insecta: Siphonaptera) and mites (Acari: Mesostigmata), parasitic on small mammals (rodents and marsupials), were studied in different localities across Brazil. A stronger effect of host-related factors on flea than on mite assemblages, and a stronger effect of environmental factors on mite than on flea assemblages were predicted. In addition, the effects of parasite-related factors on flea and mite diversity and abundance were predicted to manifest mainly at the scale of infracommunities, whereas the effects of host-related and environmental factors were predicted to manifest mainly at the scale of component and compound communities. This study found that, in general, diversity and abundance of flea and mite assemblages at two lower hierarchical levels (infracommunities and component communities) were affected by host-related, parasite-related and environmental factors, and compound communities were affected mainly by host-related and environmental factors. The effects of factors differed between fleas and mites: in fleas, community structure and abundance depended on host diversity to a greater extent than in mites. In addition, the effects of factors differed among parasite assemblages harboured by different host species.

[The genus Tunga Jarocki, 1838 (Siphonaptera: Tungidae). I: taxonomy, phylogeny, ecology and pathogenicity]

Pour la première fois, les 12 espèces actuellement décrites dans le genre Tunga sont étudiées sur le plan de la taxonomie et de la répartition. Divers aspects de leur biologie et leur rôle pathogène sont également envisagés, et en particulier leur phylogénie, leur chorologie, leur phénologie, leur sexe-ratio et leurs dermecos.

Vectors of rickettsiae in Africa

Vector-borne diseases are caused by parasites, bacteria, or viruses transmitted by the bites of hematophagous arthropods. In Africa, there has been a recent emergence of new diseases and the re-emergence of existing diseases, usually with changes in disease epidemiology (e.g., geographical distribution, prevalence, and pathogenicity). In Africa, rickettsioses are recognized as important emerging vector-borne infections in humans. Rickettsial diseases are transmitted by different types of arthropods, ticks, fleas, lice, and mites. This review will examine the roles of these different arthropod vectors and their geographical distributions.

Ectoparasitic insects (Diptera: Streblidae and Siphonaptera: Ischnopsyllidae) of bats from Iquitos and surrounding areas (Loreto, Peru)

Based on specimens collected from bats of different families, we add new species and extend the known ecological distribution and host associations of insect ectoparasites of bats in Peru. New information is provided for the distribution of 26 species of parasites (25 Diptera and 1 Siphonaptera: Ischnopsyllidae). Four species (Neotrichobius ectophyllae, Strebla galindoi, Strebla paramirabilis and Myodopsylla wolffsohni wolffsohni) are new for Peru and 16 represent new records for the department of Loreto. Also, we found 17 new host-ectoparasite relationships. Of note, we found remarkable new association between Neotrichobius delicatus and bat species from the families Molossidae and Noctilionidae and a novel association between Paradyschiria parvula and a species of Vespertilionidae. Host-ectoparasite specificity was recorded with 14 species as monoxenous, three oligoxenous, seven pleioxenous and two polyxenous.

A new species of Tunga (Siphonaptera: Tungidae) from Brazil with a key to the adult species and neosomes

Tunga bossii new species of tungid sand flea belonging to the caecata group is described with illustrations of the adult female, parasitizing the wild rodent Delomys dorsalis (Hensel) from Brazilian Atlantic Forest. Tunga bossii differs from the ten other known species of Tunginae by the size of the first segment of the maxillary palp and the presence of two bristles at the base of the maxilla. Tunga bossii also can be differentiated from other species of the T. caecata group by the eye morphology. A key to the adult species and neosomes of the genus Tunga also is included.

Checklist de Siphonaptera (Insecta) do Estado de São Paulo

As pulgas são insetos hematófagos na fase adulta e que atuam como agentes infestantes ou como vetores de patógenos. Seus hospedeiros são animais endotérmicos, essencialmente mamíferos e, predominantemente roedores. A sifonapterofauna do Estado de São Paulo representa 61,3% (38/62) da brasileira, sendo a mais rica quando comparada com outros estados em número de espécies ou gêneros. Algumas espécies são conhecidas apenas por um dos sexos; outras, através de pequeno número de exemplares colecionados. Quatro espécies (10,5%) são endêmicas no Estado. No Brasil, a principal coleção de pulgas está depositada no Museu de Zoologia da USP.

Use of Multiple Displacement Amplification as Pre-polymerase Chain Reaction (Pre-PCR) to amplify genomic DNA of siphonapterids preserved for long periods in scientific collections

The recently developed Multiple Displacement Amplification technique (MDA) allows for the production of a large quantity of high quality genomic DNA from low amounts of the original DNA. The goal of this study was to evaluate the performance of the MDA technique to amplify genomic DNA of siphonapterids that have been stored for long periods in 70% ethanol at room temperature. We subjected each DNA sample to two different methodologies: (1) amplification of mitochondrial 16S sequences without MDA; (2) amplification of 16S after MDA. All the samples obtained from these procedures were then sequenced. Only 4 samples (15.4%) subjected to method 1 showed amplification. In contrast, the application of MDA (method 2) improved the performance substantially, with 24 samples (92.3%) showing amplification, with significant difference. Interestingly, one of the samples successfully amplified with this method was originally collected in 1909. All of the sequenced samples displayed satisfactory results in quality evaluations (Phred ≥ 20) and good similarities, as identified with the BLASTn tool. Our results demonstrate that the use of MDA may be an effective tool in molecular studies involving specimens of fleas that have traditionally been considered inadequately preserved for such purposes.

Siphonaptera associated with wild mammals from the Central Atlantic Forest Biodiversity Corridor in southeastern Brazil

We collected 379 samples of eight flea species from 235 specimens of wild mammals captured in three areas of the Central Atlantic Forest Corridor in the state of Espírito Santo, southeastern Brazil, between August 2006 and February 2008. Among the 22 mammal species, we found eight species of marsupials (order Didelphimorphia), 13 species of rodents (order Rodentia), and one species of wild cat (order Carnivora). The total prevalence of infestation was 28.1%, with similar percentages in rodents (26.4%) and marsupials (29.5%). The infestation in the southern area was 3 times higher than that observed in the northern area. The infestation by single flea species was > 6 times higher than the total number of double and triple infestations. The mean abundance of fleas was 1.61. The flea female/male ratio was 1.38, ranging from 0.95 in Adoratopsylla (Tritopsylla) intermedia intermedia (Wagner) to 1.81 in Hechtiella nitidus (Johnson) in the most flea species infested. We report three new records of flea species in the state of Espírito Santo, and eight new host records.