Evidence of castrations in fleas of small mammals (Chiroptera and Rodentia) from Argentina.

Morphological abnormalities in fleas seem to be common in nature and are under reported in Argentina. In this note, we describe anomalies in two males and one female of Alectopsylla unisetosa Mahnert (Ischnopsyllidae) and one of Polygenis sp. (Rhopalopsyllidae) male collected from small mammals in the provinces of Neuquen and Salta, Argentina. In all specimens, the anomalies were observed at the level of the genitalia recognized as partial castration. The structures mainly affected were the modified abdominal segments, the aedeagus (in male), and the spermatheca (in female). The present communication is the first one devoted exclusively to teratogenous fleas in Argentina.

Comparative molecular and morphological study of Stenoponia tripectinata tripectinata (Siphonaptera: Stenoponiidae) from the Canary Islands and Corsica.

Stenoponia tripectinata tripectinata (Tiraboschi, 1902) is the most prevalent subspecies, within the genus Stenoponia, in the Mediterranean area. This rodent flea is widely distributed throughout southwestern Europe and the North of Africa including Mediterranean islands and the Canary Islands. Nevertheless, from a taxonomical and systematic point, this flea group has been neglected over the years. Therefore, the aim of this study was to carry out a comparative morphometric, phylogenetic, and molecular study of two populations of S. t. tripectinata isolated from rodents collected from different islands from the Canary Archipelago and from Corsica to clarify the taxonomic status of these two isolated populations and to assess the morphological and molecular differentiation between them. For this purpose, we have analyzed several morphological traits and sequenced five molecular markers (EF1-α, ITS2, cox1, cox2, and cytb). We observed slight differences in the overall body size between females of both populations, and two well-defined geographical genetic lineages. This suggests the existence of two cryptic subspecies within S. t. tripectinata corresponding to two different island groups. Furthermore, we bring to light the necessity to provide new and updated morphological, molecular, and phylogenetic data to clarify the taxonomic status of S. tripectinata.

CsrA Enhances Cyclic-di-GMP Biosynthesis and Yersinia pestis Biofilm Blockage of the Flea Foregut by Alleviating Hfq-Dependent Repression of the hmsT mRNA.

Plague-causing Yersinia pestis is transmitted through regurgitation when it forms a biofilm-mediated blockage in the foregut of its flea vector. This biofilm is composed of an extracellular polysaccharide substance (EPS) produced when cyclic-di-GMP (c-di-GMP) levels are elevated. The Y. pestis diguanylate cyclase enzymes HmsD and HmsT synthesize c-di-GMP. HmsD is required for biofilm blockage formation but contributes minimally to in vitro biofilms. HmsT, however, is necessary for in vitro biofilms and contributes to intermediate rates of biofilm blockage. C-di-GMP synthesis is regulated at the transcriptional and posttranscriptional levels. In this, the global RNA chaperone, Hfq, posttranscriptionally represses hmsT mRNA translation. How c-di-GMP levels and biofilm blockage formation is modulated by nutritional stimuli encountered in the flea gut is unknown. Here, the RNA-binding regulator protein CsrA, which controls c-di-GMP-mediated biofilm formation and central carbon metabolism responses in many Gammaproteobacteria, was assessed for its role in Y. pestis biofilm formation. We determined that CsrA was required for markedly greater c-di-GMP and EPS levels when Y. pestis was cultivated on alternative sugars implicated in flea biofilm blockage metabolism. Our assays, composed of mobility shifts, quantification of mRNA translation, stability, and abundance, and epistasis analyses of a csrA hfq double mutant strain substantiated that CsrA represses hfq mRNA translation, thereby alleviating Hfq-dependent repression of hmsT mRNA translation. Additionally, a csrA mutant exhibited intermediately reduced biofilm blockage rates, resembling an hmsT mutant. Hence, we reveal CsrA-mediated control of c-di-GMP synthesis in Y. pestis as a tiered, posttranscriptional regulatory process that enhances biofilm blockage-mediated transmission from fleas. IMPORTANCE Yersinia pestis, the bacterial agent of bubonic plague, produces a c-di-GMP-dependent biofilm-mediated blockage of the flea vector foregut to facilitate its transmission by flea bite. However, the intricate molecular regulatory processes that underlie c-di-GMP-dependent biofilm formation and thus, biofilm-mediated blockage in response to the nutritional environment of the flea are largely undefined. This study provides a novel mechanistic understanding of how CsrA transduces alternative sugar metabolism cues to induce c-di-GMP-dependent biofilm formation required for efficient Y. pestis regurgitative transmission through biofilm-mediated flea foregut blockage. The Y. pestis-flea interaction represents a unique, biologically relevant, in vivo perspective on the role of CsrA in biofilm regulation.

New record of Alectopsylla unisetosa (Siphonaptera: Ischnopsyllidae) from Patagonia.

Alectopsylla unisetosa (Ischnopsyllidae) from Santa Cruz province represents the second report of the species after 45 years. This new distributional record extends this species distribution 1350 km further south than previously documented. Moreover, Alectopsylla unisetosa infesting Myotis chiloensis constitutes a new flea-host association. This finding provides new insights into the biogeography and host associations within the family Ischnopsyllidae.

Illustrated Morphological Keys for Fleas (Siphonaptera) in Madagascar.

Madagascar has an important diversity of fleas (Siphonaptera), which almost species do not exist elsewhere. Scientists have provided huge efforts to improve knowledge on Malagasy fleas since the middle of 1900s particularly by investigating topics such as taxonomy, systematics, biogeography, and flea vector role. Since then, new species discovery has increased and currently, 48 species are recorded which the majority is endemic. Therefore, it becomes necessary to have updated keys to identify species membership. This paper presents morphological-based keys to identify at genus and species levels adult fleas reported as occurring in Madagascar. Illustrations are proposed to make easier the observation of morphological criteria, which may be tricky for sibling species.

Spatial and temporal variation of compositional, functional, and phylogenetic diversity in ectoparasite infracommunities harboured by small mammals.

We studied patterns of compositional, functional, and phylogenetic α- and ß-diversity in flea and gamasid mite infracommunities of small Siberian mammals, taking into account host-associated (species) and environmental (biome or sampling period) factors. We asked: (a) How do these factors and their interactions affect infracommunity diversity? (b) Does infracommunity composition, in terms of species, traits, and phylogenetic lineages, deviate from random? (c) Are species, traits, and phylogenetic lineages in infracommunities clustered or overdispersed?, and (d) Do patterns of diversity differ between the three diversity facets and/or the two ectoparasite taxa? We found that the α-diversity of infracommunities was strongly affected by host species, biome, and sampling period. The highest proportion of infracommunity diversity in both taxa was associated with the interaction between either host species and biome or host species and sampling period. Infracommunities of both taxa within, as well as between, host species, biomes, and sampling periods were characterized by the clustering of species, traits and lineages. The patterns of the effects of host species, biome, and sampling period on infracommunity diversity were congruent among the three diversity facets in both fleas and mites. We conclude that the assembly patterns in ectoparasite infracommunities mirror those characteristics of component and compound communities.

Description of a new flea species of the genus Ctenophthalmus Kolenati (Siphonaptera: Ctenophthalmidae) from Turkey.

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 Balikesir (Edremit district) province of Turkey. The number of Ctenophthalmus taxa known from Turkey now tallies 41 taxa (27 species and 14 subspecies).

Intraspecific variation of body size in fleas: effects of host sex and flea phenology.

We investigated the effects of host sex and flea phenology (estimated as periods of high versus low abundance) on individual body size in four fleas of small mammals. Amalaraeus penicilliger and Ctenophthalmus uncinatus are ectoparasites of the bank vole Myodes glareolus, whereas Doratopsylla dasycnema and Palaeopsylla soricis are ectoparasites of the common shrew Sorex araneus. We found significant effects of host sex and phenology on the body size of all flea species, although there was no general trend in the directions of these effects. Larger A. penicilliger were found on female hosts, whereas larger P. soricis were found on male hosts. In the remaining species, larger fleas were collected from male hosts during periods of high abundance (male C. uncinatus and female D. dasycnema) and from female hosts during periods of low abundance (male C. uncinatus). Regarding phenology, larger fleas were recorded during periods of either high (A. penicilliger, C. uncinatus, D. dasycnema) or low (C. uncinatus, P. soricis) abundance, but this depended on flea and/or host sex. We conclude that the directions of the host sex and phenology effects varied between flea species. Furthermore, the direction of the host sex effect was mediated by the effect of phenology and vice versa.

Description of two new species of Ectinorus (Ectinorus) (Siphonaptera, Rhopalopsyllidae) from Argentina, including a morphometric approach.

Two new species of fleas of genus Ectinorus (Siphonaptera: Rhopalopsyllidae) are described from sigmodontine rodents (Rodentia: Cricetidae) collected during a survey of small mammals in northwestern Argentina.The new species belong to the subgenus Ectinorus and can be distinguished from all other species of the subgenus by the characteristics of the modified abdominal segments and by the genitalia. Moreover, the male of Ectinorus (Ectinorus) disjugis is described for the first time and the finding of this flea parasitizing the rodent Akodon spegazzinii, constitutes a new flea-host association. A phylogenetic analysis of the genus Ectinorus, using traditional morphological characters and morphogeometric data, is presented to support the erection of the new species of Ectinorus. An identification key for all species of Ectinorus is also provided. Our study increases to 38 the total number of species of the subgenus Ectinorus, and to 20 the number for Argentina. Phylogenetic analyses reveal that Ectinorus is monophyletic but the subgenera are not. This study offers a new interpretation of morphological diversity within the genus as well as an evaluation of hypotheses about their relationships.

Taxonomic revision of the flea genus AgastopsyllaJordan & Rothschild 1923 (Siphonaptera: Ctenophthalmidae).

Fleas of Argentina are receiving renewed systematic interest, but the identification of many species associated with small mammals can be problematic. We review the taxonomy of the flea genus Agastopsylla including the re-description of two species and one subspecies, and designate neotype and neallotype for Agastopsylla hirsutior, neotype for Agastopsylla nylota nylota from the "Colección Mamíferos Lillo Anexos" (CMLA), Universidad Nacional de Tucumán, Argentina, and neotype and neallotype for Agastopsylla pearsoni from the Natural History Museum (London, U.K.). Additionally, a key to identification of the species of Agastopsylla and a distribution map of the species of the genus are included.

Ctenophthalmus baeticus boisseauorum (Beaucournu, 1968) and Ctenophthalmus apertus allani (Smit, 1955) (Siphonaptera: Ctenophthalmidae) as synonymous taxa: morphometric, phylogenetic, and molecular characterization.

The family Ctenophthalmidae (Order Siphonaptera) has been considered as a 'catchall' for a wide range of divergent taxa showing a paraphyletic origin. In turn, Ctenophthalmus sp. (Ctenophthalmidae) includes 300 valid described taxa. Within this genus, males are easily distinguishable basing on the size, shape, and chaetotaxy of their genitalia; however, females show slight morphological differences with each other. The main objective of this work was to carry out a comparative morphometric, phylogenetic, and molecular study of two different subspecies: Ctenophthalmus baeticus boisseauorum and Ctenophthalmus apertus allani in order to clarify and discuss its taxonomic status. From a morphological and biometrical point of view, we found clear differences between modified abdominal segments of males of both subspecies and slight differences in the margin of sternum VII of all female specimens which did not correspond with molecular and phylogenetic results based on four different molecular markers (Internal Transcribed Spacer 1 and 2 of ribosomal DNA, and the partial cytochrome c oxidase subunit 1 and cytochrome b of mitochondrial DNA). Thus, we observed a phenotypic plasticity between both subspecies, which did not correspond with a real genotypic variability nor different environmental or ecological conditions. Basing on these results, we could consider that there are no solid arguments to consider these two 'morphosubspecies' as two different taxa. We propose that C. b. boisseauorum should be considered as a junior synonym of C. a. allani.

Mouthpart homologies and life habits of Mesozoic long-proboscid scorpionflies.

Mesozoic long-proboscid scorpionflies (Mesopsychoidea) provide important clues to ancient plant-pollinator interactions. Among them, the family Aneuretopsychidae is especially important because its mouthparts are vital to deciphering the early evolution of Mesopsychoidea and putatively the origin of fleas (Siphonaptera). However, the identification of mouthpart homologs among Aneuretopsychidae remains controversial because of the lack of three-dimensional anatomical data. Here, we report the first Aneuretopsychidae from Late Cretaceous Burmese amber, which have short maxillary palpi and elongate mouthpart elements consisting of one pair of galeae and one hypopharynx. Their mouthparts are identical to those of Pseudopolycentropodidae (= Dualulidae, new synonym) but are not homologous to those of Siphonaptera. Our phylogenetic analysis provides robust evidence for the debated monophyly of Mesopsychoidea. Our results suggest that the long-proboscid condition has most likely evolved once in Mesopsychoidea, independently from fleas, and further reveal the variety and complexity of mid-Cretaceous pollinating insects.

A New Flea Species of the Genus Palaeopsylla (Insecta: Siphonaptera: Ctenophthalmidae) From Turkey.

A new flea (Insecta: Siphonaptera) species belonging to the Palaeopsylla minor-group, Palaeopsylla (Palaeopsylla) beaucournui n. sp. is described and illustrated. Specimens (14 males and seven females) of this new species were collected from Talpa levantis Thomas (Mammalia: Talpidae) in the deciduous mixed forest in Bursa province of Marmara Region, Turkey.

Annotated checklist of fleas (Insecta: Siphonaptera) and lice (Insecta: Anoplura) associated with rodents in Iran, with new reports of fleas and lice.

BACKGROUND & OBJECTIVES: Rodent species reported from Iran are subject of several studies, but the fauna called ectoparasite, infesting the rodents, along with their epidemic effects, are poorly known. In this study, ectoparasitic insect fauna of rodents found across the Iran were studied, to generate an annotated checklist of fleas and lice species. METHODS: Several field expeditions focused on different habitats of northeastern Iran were conducted between January 2017 and May 2018. Rodent trapping was carried out using custom-made mesh live traps and "Faragir" live traps baited mainly with scorched sunflower and gourd seeds. The trapped rodents were examined for ectoparasites on their body, and then released at their trapping point. The rodents and ectoparasite species were identified based on available keys. RESULTS: A total of 217 rodents belonging to 16 species of the families Calomyscidae, Cricetidae, Dipodidae, Mu- ridae and Sciuridae were captured. Five species of each fleas and lice were collected from the body of the trapped rodents. Three flea species, Ctenophthalmus pseudagyrtes, Nosopsyllus iranus and Xenopsylla buxtoni; and two louse species, Polyplax gerbilli and P. spinulosa, were recorded for the first time. INTERPRETATION & CONCLUSION: The study generated an annotated checklist of 79 species of fleas and 8 species of lice harboured by different species of rodents distributed in Iran which would be helpful in different taxonomic studies such as parasite-host coevolution, and also sanitation and health monitoring programs.

Descriptions of Two New Species and a New Subspecies of the Genus Ctenophthalmus (Insecta: Siphonaptera: Ctenophthalmidae) from Turkey.

Two new species and a new subspecies of fleas belonging to the genus Ctenophthalmus Kolenati (Siphonaptera: Ctenophthalmidae) were described from Turkey. Ctenophthalmus (Spalacoctenophthalmus) beyzanurae n. sp. was collected from Nannospalax leucodon Nordmann (Mammalia: Rodentia) in Tekirdag province while Ctenophthalmus (Euctenophthalmus) kefelioglui n. sp. and Ctenophthalmus (Euctenophthalmus) teres anatolicus n. ssp. were collected from Microtus guentheri (Danford & Alston) and Apodemus uralensis (Pallas) (Mammalia: Rodentia) in the Aksaray and Kars provinces of Turkey, respectively. Detailed illustrations of new taxa described were also provided.

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.

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.

Sexual size dimorphism and sex ratio in arthropod ectoparasites: contrasting patterns at different hierarchical scales.

The aims of this study were to determine whether sexual size dimorphism in fleas and gamasid mites (i) conforms to Rensch's rule (allometry of sexual size dimorphism) and (ii) covaries with sex ratio in infrapopulations (conspecific parasites harboured by an individual host), xenopopulations (conspecific parasites harboured by a population of a given host species in a locality) and suprapopulations (conspecific parasites harboured by an entire host community in a locality). Rensch's rule in sexual size dimorphism was tested across 150 flea and 55 mite species, whereas covariation between sexual size dimorphism and sex ratio was studied using data on ectoparasites collected from small mammalian hosts in Slovakia and western Siberia. For fleas, we controlled for the confounding effect of phylogeny. The slope of the linear regression of female size on male size was significantly smaller than 1 in fleas, but did not differ from 1 in mites. The proportion of males in flea infrapopulations significantly increased with an increase in the female-to-male body size ratio. The same was true for obligatory haematophagous mites. No relationship between sex ratio and sexual size dimorphism was found for xenopopulations of either taxon or for mite suprapopulations. However, when controlling for the confounding effect of phylogeny, a significant negative correlation between sex ratio and sexual size dimorphism was revealed for flea suprapopulations. We conclude that (i) some macroecological patterns differ between ectoparasite taxa exploiting the same hosts (allometry in sexual size dimorphism), whereas other patterns are similar (sexual size dimorphism-sex ratio relationship in infrapopulations), and (ii) some patterns are scale-dependent and may demonstrate the opposite trends in parasite populations at different hierarchical levels.

Fleas of the genus Neotyphloceras associated with rodents from Bolivia: new host and distributional records, description of a new species and remarks on the morphology of Neotyphloceras rosenbergi.

The flea genus Neotyphloceras Rothschild (Siphonaptera: Ctenophthalmidae) includes five species and two subspecies distributed from Venezuela to southern Chile and Argentina. Only Neotyphloceras crassispina hemisus Jordan has been registered in Bolivia. The present study examines species of Neotyphloceras collected in Bolivian localities in the Departments of La Paz, Cochabamba and Tarija, and describes the morphology of the modified abdominal segments in males and females of Neotyphloceras rosenbergi Rothschild on the basis of type material and specimens collected from Tarija. A new species, Neotyphloceras boliviensis n. sp., is described and new host associations are reported for N. rosenbergi, Neotyphloceras crassispina crassispina and N. crassispina hemisus. Neotyphloceras c. crassispina and N. rosenbergi are reported for the first time in Bolivia. The distribution of N. rosenbergi is extended 1600 km to the south. Given the potential medical and veterinary significance of fleas as disease vectors, and considering that in the Departments of La Paz and Tarija several human cases of plague have been reported, and species of flea have been identified as main vectors of these diseases, the new records of fleas in Bolivia reported herein may be useful for epidemiological studies on flea-borne diseases.

Descriptions of two new species of flea of the genus Plocopsylla in northwestern Argentina.

Two new species of flea of the genus Plocopsylla, subgenus Plocopsylla, (Siphonaptera: Stephanocircidae) collected from sigmodontine rodents in northwestern Argentina are described and a key to identification of species of the genus Plocopsylla, subgenus Plocopsylla, in Argentina is presented. Plocopsylla (P.) inti is cited for the first time in Argentina, extending its distribution ∼ 970 km further south than previously documented. New locality data and flea-host associations are recorded. The contributions of this study are relevant because they increase knowledge of the diversity of flea fauna in northwestern Argentina bordering a plague endemic area and will be useful in the implementation of plague control management plans in the future.