Ctenophthalmus Agyrtes Research Articles

Bartonella, Rickettsia, Babesia, and Hepatozoon Species in Fleas (Siphonaptera) Infesting Small Mammals of Slovakia (Central Europe).

Fleas (Siphonaptera) as obligate, blood-feeding ectoparasites are, together with ticks, hosted by small mammals and can transmit causative agents of serious infections. This study aimed to determine and characterize the presence and genetic diversity of Bartonella, Rickettsia, and apicomplexan parasites (Babesia, Hepatozoon) in fleas feeding on small mammals from three different habitat types (suburban, natural, and rural) in Slovakia. The most common pathogen in the examined fleas was Bartonella spp. (33.98%; 95% CI: 30.38–37.58), followed by Rickettsia spp. (19.1%; 95% CI: 16.25–22.24) and apicomplexan parasites (4.36%; 95% CI: 2.81–5.91). Bartonella strains belonging to B. taylorii, B. grahamii, B. elizabethae, Bartonella sp. wbs11, and B. rochalimae clades were identified in Ctenophthalmus agyrtes, C. congener, C. assimilis, C. sciurorum, C. solutus, C. bisoctodentatus, Palaeopsylla similis, Megabothris turbidus, and Nosopsyllus fasciatus within all habitats. The presence of Rickettsia helvetica, R. monacensis, and rickettsiae, belonging to the R. akari and R. felis clusters, and endosymbionts with a 96–100% identity with the Rickettsia endosymbiont of Nosopsyllus laeviceps laeviceps were also revealed in C. agyrtes, C. solutus, C. assimilis, C. congener, M. turbidus, and N. fasciatus. Babesia and Hepatozoon DNA was detected in the fleas from all habitat types. Hepatozoon sp. was detected in C. agyrtes, C. assimilis, and M. turbidus, while Babesia microti was identified from C. agyrtes, C. congener, and P. similis. The present study demonstrated the presence of zoonotic pathogens in fleas, parasitizing the wild-living small mammals of southwestern and central Slovakia and widens our knowledge of the ecology and genomic diversity of Bartonella, Rickettsia, Babesia, and Hepatozoon.

Ctenophthalmus agyrtes agyrtes

This datasheet on Ctenophthalmus agyrtes agyrtes covers Identity, Distribution, Hosts/Species Affected.

Bartonella spp. in Small Mammals and Their Fleas in Differently Structured Habitats From Germany.

Most Bartonella spp. are transmitted by fleas and harbored by small mammals which serve as reservoirs. However, little is known about the composition of fleas and their Bartonella spp. from small mammals in Central Europe. Therefore, the aims of this study were to investigate flea communities on small mammals from three differently structured sites (urban, sylvatic, renatured) in Germany as well as the prevalence of Bartonella spp. in small mammals and their parasitizing fleas. In total, 623 small mammals belonging to 10 different species (the majority were Myodes glareolus and Apodemus flavicollis) were available. Fleas were removed from the small mammals' fur, morphologically identified and DNA was extracted. To detect Bartonella spp., two conventional PCRs targeting the gltA gene and the 16S−23S rRNA intergenic spacer were carried out followed by sequencing. Obtained sequences were compared to those in GenBank. In total, 1,156 fleas were collected from 456 small mammals. Altogether, 12 different flea species (the majority were Ctenophthalmus agyrtes, Nosopsyllus fasciatus, and Megabothris turbidus) were detected. At the urban site mostly Leptopsylla segnis and N. fasciatus were collected which may be vectors of zoonotic pathogens to companion animals. The overall prevalence for Bartonella in small mammals was 43.3% and in fleas 49.1%. Five different Bartonella spp. were detected in small mammals namely B. grahamii, B. taylorii, B. doshiae, Bartonella sp. N40 and uncultured Bartonella sp. whereas in fleas four Bartonella spp. were found which were with the exception of B. doshiae identical to the Bartonella species detected in their small mammal hosts. While B. grahamii was the only zoonotic Bartonella sp. most Bartonella strains found in fleas and small mammals belonged to uncultured Bartonella spp. with unknown zoonotic potential. This study showed a high diversity of flea species on small mammals from Germany. Further, high prevalence rates of Bartonella species were detected both in fleas and in their mammalian hosts. Several different Bartonella species with a high genetic variability were discovered. Especially at the urban study sites, this may pose a risk for Bartonella transmission to companion animals and humans.

Flea Communities on Small Rodents in Eastern Poland.

Simple SummaryFleas are obligatory, secondarily wingless, hematophagous insects living all over the world. They colonize a variety of habitats from wet tropical forests to semi-arid and desert areas. Adult individuals feed mainly on small mammals, and less often on birds. The aim of the present study was to explore the fauna of fleas and their broad-sense behavior in eastern Poland. Rodents, which are widely recognized as one of the preferred hosts of these insects, were caught to carry out the study. The results show that, regardless of the ecological habitat type, the striped field mouse Apodemus agrarius was the most frequently captured rodent species, and the Ctenophthalmus agyrtes flea species was collected most frequently. Moreover, rhythms in the seasonal activity of fleas, with a peak in summer months, were noted.Fleas are hematophagous insects infesting mainly small mammals and, less frequently, birds. With their wide range of potential hosts, fleas play a significant role in the circulation of pathogens in nature. Depending on the species, they can be vectors for viruses, bacteria, rickettsiae, and protozoa and a host for some larval forms of tapeworm species. The aim of this study was to determine the species composition of fleas and their small rodent host preferences in eastern Poland. Animals were captured in traps in various types of ecological habitats (a site covered by grassland vegetation within city limits, an unused agricultural meadow, and a fallow land near a mixed forest). The following rodent species were caught: Apodemus agrarius, Apodemus flavicollis, Microtus arvalis, and Myodes glareolus. Additionally, Ctenophthalmus agyrtes, Ctenophthalmus assimilis, Hystrichopsylla talpae, and Nosopsyllus fasciatus flea species were identified. The peak of the flea activity was noted in summer months. C. agyrtes was found to be the most abundant flea species in eastern Poland, while the greatest numbers of fleas were collected from the rodent species A. agrarius.

Flea Communities on Small Mammals in Lowland Environment

Abstract The landscape of south-western Slovakia is characterised by anthropogenous reshaping, while fragments of undisturbed, waterlogged habitats have been preserved in what remains of the meandering ancient Žitava River. These refuges are inhabited by various small mammal species and their blood-sucking ectoparasites. Between 2014 and 2018, research on them was carried out in Slovakia’s Danubian Lowland (Podunajská nížina) during three out of the four seasons (spring, summer and autumn). The small mammals were captured at 27 localities. The occurrence of nine flee species from the Hystrichopsyllidae, Ctenophthalmidae and Ceratophyllidae families was documented on 12 small burrowing mammals. During the course of all the seasons in which research was conducted, Ctenophthalmus agyrtes, C. assimilis, Megabothris turbidus a Nosopsyllus fasciatus were found, among the most dominant species to be seen on small burrowing mammals.

Ticks, fleas and rodent-hosts analyzed for the presence of Borrelia miyamotoi in Slovakia: the first record of Borrelia miyamotoi in a Haemaphysalis inermis tick

In Slovakia, little knowledge is available on the occurrence, hosts and vectors of Borrelia miyamotoi of the relapsing fever group. In the current study, 2160 questing and rodent-attached ticks of six species (Ixodes ricinus, Ixodes trianguliceps, Dermacentor marginatus, Dermacentor reticulatus, Haemaphysalis concinna and Haemaphysalis inermis), 279 fleas belonging to 9 species (Ctenophthalmus agyrtes, Ctenophthalmus solutus, Ctenophthalmus assimilis, Megabothris turbidus, Amalareus penicilliger, Hystrichopsylla orientalis, Ctenophthalmus uncinatus, Doratopsylla dasycnema and Nosopsyllus fasciatus) and skin biopsies from 245 small mammals belonging to eight species (Apodemus agrarius, Apodemus flavicollis, Apodemus uralensis, Myodes glareolus, Crocidura leucodon, Micromys minutus, Microtus arvalis, Microtus subterraneus) were screened for the presence of B. miyamotoi DNA. The overall prevalence of B. miyamotoi found in questing and rodent-attached ticks was 1.8% (23 positive/1260 examined) and 3.4% (31 positive/900 examined), respectively. Borrelia miyamotoi was detected in questing I. ricinus, rodent-attached I. ricinus and H. inermis ticks, and in one male of the common vole (M. arvalis) in different habitats (mainly rural) in eastern Slovakia. However, B. miyamotoi was not found in any of the tested fleas. Our findings indicate that rural habitats with different species of tick vectors and hosts are appropriate for the occurrence of B. miyamotoi.

Fleas (Insecta: Siphonaptera) collected from some small mammals (Mammalia: Rodentia, Eulipotyphla) in Turkey, with new records and new host associations

Fleas (Insecta: Siphonaptera) are among the most common ectoparasites of small mammals. We investigated fleas infesting on the small mammals (Mammalia: Rodentia, Eulipotyphla) from 15 different localities in Turkey. A total of 276 flea (133 males and 143 females) specimens belonging to 32 different flea taxa were collected from 90 (42 males, 16 females and 32 undetermined) small mammals belonging to 20 different species. With many new flea-host associations, the first occurrences of Ctenophthalmus agyrtes peusianus Rosicky, Ctenophthalmus golovi golovi Ioff & Tiflov, Ctenophthalmus secundus vicarius Jordan & Rothschild, Doratopsylla dasycnema cuspis Rothschild, Leptopsylla algira popovi (Wagner & Argyropulo) and Rhadinopsylla pentacantha (Rothschild) fleas were reported in Turkey. In addition, three flea species, Ctenophthalmus coniunctus Peus, Ctenophthalmus contiger Peus, and Palaeopsylla incisa Peus, are reported for only the second time since their original descriptions.

Detection of Rickettsia spp. in Fleas Collected from Small Mammals in Slovakia, Central Europe

This survey is aimed at investigation of species composition of fleas removed from small terrestrial mammals captured in rural, suburban, and urban types of habitat and molecular screening of the presence and diversity of Rickettsia species in collected ectoparasites. In total, 279 fleas (Siphonaptera) belonging to 9 species of 2 families, Ceratophyllidae and Hystrichopsyllidae, were collected from 115 (46%) out of 250 trapped small mammals of eight species (Apodemus agrarius, Apodemus flavicollis, Apodemus uralensis, Myodes glareolus, Microtus arvalis, Microtus subterraneus, Crocidura leucodon, and Sorex minutus). Rickettsia spp. were found in 2.5% (7/279) of tested fleas, namely in Ctenophthalmus agyrtes, Ctenophthalmus solutus, Ctenophthalmus uncinatus, Megabothris turbidus, and Amalareus penicilliger. Rickettsia felis, Rickettsia helvetica, and unidentified Rickettsia species were detected in fleas infesting small mammals in Eastern Slovakia. The results of the study suggest that some species of rickettsiae have a different range of arthropod vectors.

Identification of Hepatozoon erhardovae Krampitz, 1964 from bank voles (Myodes glareolus) and fleas in Southern Hungary.

In order to investigate the prevalence and life cycle of apicomplexan parasites, small mammals were live-trapped with modified Sherman traps in Southern Hungary between 2010 and 2012. Altogether, 528 rodents (Apodemus flavicollis Melchior, 1834, Apodemus agrarius Pallas, 1771, Myodes glareolus Schreber, 1780, Microtus agrestis Linnaeus, 1761, Mus musculus Linnaeus, 1758 and Micromys minutus Pallas, 1771) were collected and four shrews (Sorex spp.) were by-catched. Captured animals belonging to non-protected species were euthanized, and spleen samples were preserved for histological and molecular analyses. During the examination of spleen smears, Hepatozoon parasites were observed in eight out of 48 bank voles (M. glareolus). DNA was isolated from altogether 221 spleen samples, and 18S rDNA was amplified using two different PCR protocols. The eight bank vole samples were positive with PCR, but none of the other M. glareolus spleen samples or any of the tissue samples from other species were found to be infected. Sequenced amplicons were very similar to Hepatozoon spp. detected in M. glareolus in Spain and Poland. Ectoparasites were collected from the small mammal carcasses and from the vegetation. Hepatozoon DNA was not found in the 181 ticks removed from the small mammals or in the 162 ticks collected with flagging, but was detected in all three flea species (4/43 Megabothris turbidus Rothschild, 1909, 3/10 Ctenophthalmus assimilis Taschenberg, 1880 and 7/78 Ctenophthalmus agyrtes Heller, 1896). Based on gamont morphology, vertebrate and arthropod host species and DNA sequences, the parasites in our study can be identified as Hepatozoon erhardovae.

Rickettsia species in fleas collected from small mammals in Slovakia.

Epidemiological and epizootiological studies of Rickettsia felis and other Rickettsia spp. are very important, because their natural cycle has not yet been established completely. In total, 315 fleas (Siphonaptera) of 11 species of Ceratophyllidae, Hystrichopsyllidae and Leptopsyllidae families were tested for the presence of Rickettsia species and Coxiella burnetii with conventional and specific quantitative real-time PCR assays. Fleas were collected from five rodent hosts (Myodes glareolus, Apodemus flavicollis, Apodemus agrarius, Microtus subterraneus, Microtus arvalis) and three shrew species (Sorex araneus, Neomys fodiens, Crocidura suaveolens) captured in Eastern and Southern Slovakia. Overall, Rickettsia spp. was found in 10.8% (34/315) of the tested fleas of Ctenophthalmus agyrtes, Ctenophthalmus solutus, Ctenophthalmus uncinatus and Nosopsyllus fasciatus species. Infected fleas were coming from A. flavicollis, A. agrarius, and M. glareolus captured in Eastern Slovakia. C. burnetii was not found in any fleas. R. felis, Rickettsia helvetica, unidentified Rickettsia, and rickettsial endosymbionts were identified in fleas infesting small mammals in the Košice region, Eastern Slovakia. This study is the first report of R. felis infection in C. solutus male flea collected from A. agrarius in Slovakia.

Fleas (Siphonaptera) in the Nests of Dormice (Gliridae: Rodentia) in Lithuania

Negative effects of flea (Siphonaptera) parasitism on the host may be expressed in different ways. The aim of this study was to assess distribution of the flea fauna in nests of dormice in Lithuania. Nests of Glis glis (L.), Dryomys nitedula (Pallas), and Muscardinus avellanarius (L.) were collected from nest boxes in 2012 and 2013. Fleas were collected from nests in the laboratory and put into plastic tubes with 70% ethanol. Flea species were identified using morphological keys. From 400 nest boxes, 112 nests of dormice were collected from eight sites from mixed forests of central Lithuania. Twenty-three nests of G. glis were collected from nest boxes, with 16 of them containing 286 fleas belonging to four species: Ceratophyllus sciurorum (Schrank) (259), C. gallinae (Schrank) (23), Hystrichopsylla talpae (Curtis) (3), and Megabothris turbidus (Rothschild) (1). Fourteen nests of M. avellanarius were collected from nest boxes, 4 of which contained 224 fleas belonging to two species: C. sciurorum (221) and C. gallinae (3). Twenty-four nests of D. nitedula were collected from nest boxes, including 17 containing 207 fleas belonging to two species: C. sciurorum (205) and C. gallinae (2). Fifty-one nests of undetermined dormice species also were collected from nest boxes, 12 of them contained 395 fleas belonging to three species: C. sciurorum (374), Ctenophthalmus agyrtes (Heller) (19), and Ctenophthalmus assimilis (Taschenberg) (2). C. sciurorum was a predominant species in the nests of dormice. The occurrence of C. gallinae was documented in Lithuania for the first time.

Monitoring výskytu drobných hlodavců a související zdravotní rizika v odchovně lovné pernaté zvěře

Using live trapping devices we performed surveillance of small vertebrates in the game bird farm in Jinačovice in 2005 to 2006. The study was aimed at determining the species composition and numbers within individual technologies of rearing as well as finding possible reservoirs or sources of infectious agents. Five study areas were examined in 2005 and other three located within buildings were added in 2006. A line of 10 traps approximately 2 metres apart was employed on each study area. Small mammals trapped were sampled for parasitology and serology.Until the present, a total of 92 common species were captured – i.e., yellow-necked fieldmouse (Apodemus flavicollis), house mouse (Mus musculus), common vole (Microtus arvalis) and bank vole (Clethrionomys glareolus). Considering endoparasites, we found nematodes such as Aspicularis tetraptera and Syphacia obvelata, Catenotaenia spp. and undetermined members of the order Eucoccidiida. Ectoparasites included members of the order Siphonaptera – Ctenophthalmus solutus, Ctenophthalmus agyrtes, Megabothris (Gebiella) turbidus and Ctenophthalmus (Euct.) assimilis and order Acarina – Ixodes ricinus and Laelaps hilaris. Serology revealed antibodies against Leptospira grippotyphosa and L. sejroe.

Phoresy of astigmatic mites on ticks and fleas in Poland

Abstract Phoresy is an association in which a small animal clings to a larger one exclusively for transportation. We searched for phoretic mites on fleas and ticks of small mammals. A total of 169 fleas of 7 species were collected in the Białowieża Forest (E Poland) and in Kosewo G órne (NE Poland) in July and August in 2007 and 2008. Moreover, 20 nymphs and 12 females of Ixodes hexagonus (Leach, 1815) were collected in the beaver farm of the Research Station of Polish Academy of Sciences in Popielno (NE Poland) in April and May 2009. Phoretic mites were found on 26 fleas (15.4%) of the following species: Megabothris walkeri (Rothschild, 1902), Megabothris turbidus (Rothschild, 1909), Ctenophthalmus agyrtes (Heller, 1896), and Hystrichopsylla orientalis (Smit, 1956). The mites were located mainly on abdominal sternites. Among ticks, only one female was positive for mites, whose larvae (hypopi) were found on its legs. A total of 6 species of mites were identified. On I. hexagonus, we found Acarus farris (Oudemans, 1905) (53 larvae), Acarus siro (L., 1758) (2 larvae), Acarus nidicolous (Griffiths, 1970) (1 larva), Caloglyphus rhizoglyphoides (Zachvatkin, 1937) (1 larva), and Histiostoma feroniarum (Dufour, 1904) (28 larvae), whereas on fleas, 79 larvae of Acarus nidicolous, 1 male of Tyrophagus putrescentiae (Schrank, 1781), and 1 unidentified trombiculid larva. The last 2 mite specimens were found on M. turbidus. This is the first report on phoretic association of the flea H. orientalis and the tick I. hexagonus with mites

The occurrence of Borrelia burgdorferi sensu lato in certain ectoparasites (Mesostigmata, Siphonaptera) of Apodemus flavicollis and Myodes glareolus in chosen localities in the Czech Republic

Ticks represent the primary vectors of several serious diseases, including the Lyme disease caused by Borrelia burgdorferi sensu lato (Bbsl). In this study two dominant ectoparasitic groups of arthropods (Mesostigmata, Siphonaptera) were investigated for the presence of borrelian DNA in order to determine their potential role of vectors (or carriers) of this bacterium. All individuals (235) were collected from wild-living rodents obtained in three localities in the Czech Republic (Bažantula, Baba and Křižovice). The majority of parasites were members of the families Parasitidae and Dermanyssidae (Mesostigmata) and families Hystrichopsyllidae and Ceratophyllidae (Siphonaptera). The rodent host species was almost exclusively the yellow-necked mouse (Apodemus flavicollis). Bbsl was detected by the PCR method in the following ectoparasite species: Euryparasitus emarginatus (1), Eulaelaps stabularis (1), Haemogamassus nidi (1), Laelaps agilis (5), Myonyssus gigas (1) (Mesostigmata) and Ctenophthalmus agyrtes (1), C. solutus (3) (Siphonaptera).

Investigation of pathogens in fleas from Lithuania

Fleas are one of the arthropod vectors for several infectious disease causing agents. In this study we detect pathogens in fleas (Ctenophthalmus agyrtes, Megabothris turbidus, M. walkeri, Hystrichopsylla talpae, and Ceratophyllus sciurorum) collected from rodents (Apodemus agrarius, Apodemus flavicollis, Myodes glareolus, Microtus agrestis, Microtus arvalis, Sciurus vulgaris) by molecular methods. The prevalence of B. burgdorferi s. l. infection in rodent and 237 fleas samples was determined by polymerase chain reaction using primers SL-F and SL-R. The prevalence of Rickettsiales pathogens infection in fleas samples was determined by polymerase chain reaction using 16s rRNR gene primers EHR521 and EHR747. For the first time pathogens of Rickettsiales order were detected in fleas from Lithuania using 16s rRNR gene.

Diversité du cortège en Siphonaptères chez le tamia de Sibérie (Tamias sibiricusLaxmann) introduit en Forêt de Sénart (Ile-de-France)

We examined the fleas community in an introduced population of Siberian chipmunks, Tamias sibiricus, between 2005 and 2007, in the Forest of Sénart (Essonne, France). We collected and identified 383 fleas on 463 chipmunks (total: 1,891 captures on 471 chipmunks). In 2005, 120 fleas were also collected on 65 bank voles, Clethrionomys glareolus, and on 25 wood mice, Apodemus sylvaticus, trapped within the same area. Ceratophyllus sciurorum sciurorum formed 73.6% of the chipmunks' flea community, with an annual prevalence (P) ranging between 8 and 13% and a mean intensity (I) ranging between 1.1 and 1.6 fleas per individual. Among the six other species infecting this Sciurid, Ctenophthalmus agyrtes impavidus constituted 17.2% (P: 1.6-2.2%; I: 1.1-2.6), and Megabothris turbidus 8.1% (P: 0.8-1.9%; I: 1.0-1.4) of the flea community, respectively. These last two species represented respectively 60.8% and 36.6% of the flea community on the bank vole and the wood mouse. Originated from Asia, chipmunks did not import any flea species to Sénart, probably because they were used as pets before their release in the wild. Abundance in C. s. sciurorum increased with adult chipmunk density and with juvenile density in summer. On adult chipmunks C. s. sciurorum tented to decrease with increasing abundance of red squirrels (Sciurus vulgaris]. Moreover, the two other flea species mainly infected young chipmunks during the fall, and their number was not related to chipmunk density. However, the distribution of species within the flea community became more balanced with increase juvenile chipmunk density. Overall, these results indicate that the close phyletic relationship between chipmunks and red squirrels contributed in the acquisition and the spread of fleas by chipmunks. Primary and secondary hosts densities, their habitat use, and more specifically burrowing activities and tree canopy use, also played a role in the spread of fleas on chipmunks.

Parasite fauna of the bank vole (Clethrionomys glareolus) in an urban region of Germany: reservoir host of zoonotic metazoan parasites?

In the present study, 29 bank voles (Clethrionomys glareolus) were studied for their endo- and ectoparasite fauna. The rodents were trapped in Dormagen, a city in North Rhine-Westphalia, Germany. A total of ten different parasite species were identified: four endoparasite (four Nematoda) and six ectoparasite (three Insecta, three Arachnida) species. The predominant endoparasite was the nematode Aonchotheca murissylvatici, followed by the nematode Heligmosomum costellatum, while the flea Ctenophthalmus agyrtes was the dominant ectoparasite. C. glareolus usually carried one to five different parasite species (mean 2.2). The bank voles were infected only by Nematoda, while Digenea or Cestoda species were not detected. The present findings are in clear contrast to the results obtained in other geographical regions of Germany and Europe, where eight different Cestoda species constituted the main part of the helminth parasites in C. glareolus. In the area investigated, the bank voles harbored no zoonotic parasites, and therefore, they play not a role as potential reservoir host for these parasite species.

Parasites of two abundant sympatric rodent species in relation to host phylogeny and ecology

In the present study, two abundant sympatric rodent species (27 Apodemus flavicollis and 33 A. sylvaticus) were studied for their endo- and ectoparasite fauna. The rodents were trapped in Dormagen, a city in North Rhine-Westphalia, Germany. A total of 20 different parasites species were identified, 13 endoparasite (2 Digenea, 5 Cestoda and 7 Nematoda) and 7 ectoparasite (5 Insecta and 2 Arachnida) species. Thirteen parasite species were found inhabiting both rodent species. The predominant endoparasite species in both rodents was the nematode Pelodera strongyloides, followed by the nematode Heligmosomoides polygyrus and a Syphacia species. The flea Ctenophthalmus agyrtes was the dominant ectoparasite in both rodent species. A. flavicollis usually carried 1-7 ecto-/endoparasite species (mean 4.0), whereas A. sylvaticus were mostly infested with 1-9 (mean 4.4). The parasite diversity of A. flavicollis (H' = 0.268, J = 0.097) was marginal lower in comparison to A. sylvaticus (H' = 0.319, J = 0.110). The two rodent species examined show remarkable similarities in the composition of their endo- and ectoparasite fauna being directly related to their similar pattern of living in the investigated area.

Ectoparasites on small mammals in Iceland: Origin and population characteristics of a species‐poor insular community

The Icelandic small mammal fauna is depauperated as is the associated ectoparasite fauna. Three small mammal species occur, viz. Apodemus sylvaticus L., Mus musculus L., and Rattus norvegicus Berk. (R. rattus is probably not a regular member). The mice supposedly came to the island by settlers from the 10th century and onwards. Apodemus and Mus from five localities altogether had seven ectoparasite species, five mites and two fleas. All species occurred on Apodemus whereas Mus was infested by four. Compared with the numbers of ectoparasite species recorded in similar studies in the Nordic countries, there are conspicuously few species in Iceland. Further, Apodemus had an overall higher infestation frequency than Mus (90% and 30%, respectively) and a higher total density of ectoparasites (3.3–20.3 and 0.5 inds/host, respectively). The density figures were high compared with those for mainland Apodemus. Especially the mite Laelaps agilis C. L. Koch and the flea Ctenophthalmus agyrtes (Heller) were common on Icelandic Apodemus. Reduced competition among parasites and/or low predator pressure on small mammals may explain the density figures obtained.The ectoparasite species compositions on small mammals in Scandinavia and Iceland have many features in common that renders it probable that Apodemus originate from Scandinavia.

I. Report on Rat-Fleas in Suffolk and North Essex

To summarize our principal observations made in the course of the investigation into the rat-fleas of the suspected plague area of East Suffolk, July—October, 1911:(1) We found an average of four fleas per rat: 822 rats were examined and 3293 fleas taken.(2) The average was subject to a local variation (0·6 to 6·5).(3) 15 species of fleas were taken from the rats, but of these there were only two species, C. fasciatus and C. agyrtes, which occurred in any numbers.There were C. fasciatus 1986 or about 60 per cent.C. agyrtes 1257 or about 38 per cent.Rare species 50 or about 2 per cent.(4) The average number of fleas per rat and the percentage of rats infested by fleas showed a well-marked seasonal variation, there being a considerable decline in the numbers as the cooler weather came on. Ceratophyllus fasciatus and Ctenophthalmus agyrtes both participated in a similar way in this variation.(5) C. fasciatus is chiefly found on rats caught near human habitations; C. agyrtes on those caught in the hedgerows.