Bird fleas (Insecta: Siphonaptera): taxonomic diversity, biogeographical distribution

If Mammals are the primary hosts of Siphonaptera, 6% of them have changed their trophic appetency for Birds. What are the reasons, what are the adaptations to be adopted by Fleas, what are the families or species groups of fleas concerned, and at last what are the host-families? As to this last question, it is clear that deviation was ecological but not phyletical.     

Do fleas (Insecta: Siphonaptera) parallel their mammal host diversification in the Mexican transition zone?

Aim The Mexican transition zone is a complex area where Neotropical and Nearctic biotic elements overlap. A previous study on mammal species has shown a great diversification in the area. We analyse the diversification of their flea species (Insecta: Siphonaptera), in order to determine if a diversification similar to their mammal host species has occurred. Location The area analysed corresponds to Mexico. Methods The panbiogeographical or track analysis was based on the comparison of the individual tracks of 112 species belonging to 48 genera and eight families of the order Siphonaptera. Generalized tracks were obtained based on the comparison of the individual tracks. Nodes were found in the areas where generalized tracks overlapped. Results Thirty‐four generalized tracks were obtained, distributed within the Mexican transition zone (20), the Nearctic region plus the Mexican transition zone (8), the Nearctic region (4) and the Neotropical region plus the Mexican transition zone (2). In the areas where they intersected, 26 nodes were identified: 23 in the Mexican transition zone and 3 in the Nearctic region. Main conclusions The nodes are concentrated in the Transmexican Volcanic Belt (14), Sierra Madre Oriental (5) and Sierra Madre del Sur (4) provinces of the Mexican transition zone. These results show a significant diversification of the flea taxa, in parallel with the diversification of their mammal hosts.     

Detection of Rickettsia spp. and host and habitat associations of fleas (Siphonaptera) in eastern Taiwan

Rickettsia typhi and Rickettsia felis (Rickettsiales: Rickettsiaceae) are two rickettsiae principally transmitted by fleas, but the detection of either pathogen has rarely been attempted in Taiwan. Of 2048 small mammals trapped in eastern Taiwan, Apodemus agrarius Pallas (24.5%) and Mus caroli Bonhote (24.4%) (both: Rodentia: Muridae) were the most abundant, and M. caroli hosted the highest proportion of fleas (63.9% of 330 fleas). Two flea species were identified: Stivalius aporus Jordan and Rothschild (Siphonaptera: Stivaliidae), and Acropsylla episema Rothschild (Siphonaptera: Leptopsyllidae). Nested polymerase chain reaction targeting parts of the ompB and gltA genes showed six fleas to be positive for Rickettsia spp. (3.8% of 160 samples), which showed the greatest similarity to R. felis, Rickettsia japonica, Rickettsia conorii or Rickettsia sp. TwKM01. Rickettsia typhi was not detected in the fleas and Rickettsia co-infection did not occur. Both flea species were more abundant during months with lower temperatures and less rainfall, and flea abundance on M. caroli was not related to soil hardness, vegetative height, ground cover by litter or by understory layer, or the abundance of M. caroli. Our study reveals the potential circulation of R. felis and other rickettsiae in eastern Taiwan, necessitating further surveillance of rickettsial diseases in this region. This is especially important because many novel rickettsioses are emerging worldwide.     

A molecular phylogeny of the Odonata (Insecta)

Abstract. We estimated the phylogeny of the order Odonata, based on sequences of the nuclear ribosomal genes 5.8 S, 18S, and ITS1 and 2. An 18S‐only analysis resolved deep relationships well: the order Odonata, as well as suborders Zygoptera and Epiprocta (Anisoptera + Epiophlebia), emerged as monophyletic. Some other deep clades resolved well, but support for more recently diverged clades was generally weak. A second, simultaneous, analysis of the 5.8S and 18S genes with the intergenic spacers ITS1 and 2 resolved some recent branches better, but appeared less reliable for deep clades with, for example, suborder Anisoptera emerging as paraphyletic and Epiophlebia superstes recovered as an Anisopteran, embedded within aeshnoid‐like anisopterans and sister to the cordulegastrids. Most existing family levels in the Anisoptera were confirmed as monophyletic clades in both analyses. However, within the corduliids that form a major monophyletic clade with the Libellulidae, several subclades were recovered, of which at least Macromiidae and Oxygastridae are accepted at the family level. In the Zygoptera, the situation is complex. The lestid‐like family groups (here called Lestomorpha) emerged as sister taxon to all other zygopterans, with Hemiphlebia sister to all other lestomorphs. Platystictidae formed a second monophylum, subordinated to lestomorphs. At the next level, some traditional clades were confirmed, but the tropical families Megapodagrionidae and Amphipterygidae were recovered as strongly polyphyletic, and tended to nest within the clade Caloptera, rendering it polyphyletic. Platycnemididae were also non‐monophyletic, with several representatives of uncertain placement. Coenagrionids were diphyletic. True Platycnemididae and non‐American Protoneurids are closely related, but their relationship to the other zygopterans remains obscure and needs more study. New World protoneurids appeared relatively unrelated to old world + Australian protoneurids. Several recent taxonomic changes at the genus level, based on morphology, were confirmed, but other morphology‐based taxonomies have misclassified taxa considered currently as Megapodagrionidae, Platycnemididae and Amphipterygidae and have underestimated the number of family‐level clades.     

Molecular phylogeny and novel host associations of avian chewing lice (Insecta: Phthiraptera) from South Africa

Compared with Europe and the Americas, the ectoparasites of African birds are poorly understood, despite the avian fauna being relatively well known. Notably, previous studies documenting the host associations and genetic diversity of parasitic chewing lice of southern African birds have been limited in geographic and taxonomic scope. Recent field expeditions exploring the avian diversity in South Africa facilitated an opportunity to obtain louse specimens from a taxonomically diverse host assemblage. This study is the first to investigate avian louse host associations and diversity across a large portion of South Africa encompassing several distinct habitat types, while incorporating molecular genetic data (from portions of the mitochondrial COI and nuclear EF‐1α genes) for ectoparasite phylogenetic analyses. From 1105 South African bird individuals and 170 species examined for lice, a total of 105 new louse–host associations were observed. Morphological and genetic examination of lice with these new host associations reveals a maximum of 66 louse species new to science. Results of this study support the observation that examining museum specimens is a useful way to investigate louse diversity and host associations.     

Geographical variation in host specificity of fleas (Siphonaptera) parasitic on small mammals: the influence of phylogeny and local environmental conditions

The evolution of host specificity remains a central issue in the study of host‐parasite relationships. Here we tackle three basic questions about host specificity using data on host use by fleas (Siphonaptera) from 21 geographical regions. First, are the host species exploited by a flea species no more than a random draw from the locally available host species, or do they form a taxonomically distinct subset? Using randomization tests, we showed that in the majority of cases, the taxonomic distinctness (measured as the average taxonomic distances among host species) of the hosts exploited by a flea is no different from that of random subsets of hosts taken from the regional pool. In the several cases where a difference was found, the taxonomic distinctness of the hosts used by a flea was almost always lower than that of the random subsets, suggesting that the parasites use hosts within a narrower taxonomic spectrum than what is available to them. Second, given the variation in host specificity among populations of the same flea species, is host specificity truly a species character? We found that host specificity measures are repeatable among different populations of the same flea species: host specificity varies significantly more among flea species than within flea species. This was true for both measures of host specificity used in the analyses: the number of host species exploited, and the index measuring the average taxonomic distinctness of the host species and its variance. Third, what causes geographical variation in host specificity among populations of the same flea species? In the vast majority of flea species, neither of our two measures of host specificity correlated with either the regional number of potential host species or their taxonomic distinctness, or the distance between the sampled region and the center of the flea's geographical range. However, in most flea species host specificity correlated with measures of the deviation in climatic conditions (precipitation and temperature) between the sampled region and the average conditions computed across the flea's entire range. Overall, these results suggest that host specificity in fleas is to a large extent phylogenetically constrained, while still strongly influenced by local environmental conditions.     

Systematics and evolution of the genus Paraceroglyphus and related taxa (Acari: Acaridae) associated with fleas (Insecta: Siphonaptera)

Collections of fleas from terrestrial Sciuridae from New Mexico and Montana yielded 2 species of acarid mites: Acarus monopsyllus from Ceratophyllus ciliatus and Paraceroglyphus cynomydis n. sp. from 4 species of Oropsylla. The genera Acarus, Paraceroglyphus, and Trichopsyllopus form a clade distinct from other genera of flea-associated mites, with Paraceroglyphus the sister group of the other 2 genera. Paraceroglyphus cynomydis is the sister group of a clade comprising P. xenopsylla and possibly P. californicus, with P. meles as the nearest outgroup.     

Wolbachia endosymbionts in fleas (Siphonaptera)

Intracellular endosymbionts, Wolbachia spp., have been reported in many different orders of insects and in nematodes but not previously in fleas. This is the first conclusive report of Wolbachia spp. within members of the Siphonaptera. Using nested polymerase chain reaction (PCR) targeting of the 16S ribosomal RNA gene, we screened for Wolbachia spp. in fleas collected from 3 counties in Georgia and 1 in New York. The prevalence of Wolbachia spp. detected varied among the 6 different species screened: 21% in the cat flea Ctenocephalides felis (n = 604), 7% in the dog flea C. canis (n = 28), 25% in Polygenus gwyni (n = 8), 80% in Orchopeas howardi (n = 15), 94% in Pulex simulans (n = 255), and 24% in the sticktight flea Echidnophaga gallinacea (n = 101). Wolbachia spp. infection in fleas was confirmed by sequencing positive PCR products, comparing sequenced 16S ribosomal DNA (rDNA) with Wolbachia spp. sequences in GenBank using BLAST search, and subjecting sequence data to phylogenetic analysis. For further confirmation, 16S rDNA-positive samples were reamplified using the wsp gene.     

Host associations and origin in the formation of the Caucasian fauna of fleas (Siphonaptera)

Results of analysis of the Caucasian fauna of fleas and their association with mammal and avian hosts are reported. The Caucasian fauna of potential flea hosts comprises about 130 species of mammals and about 470 species of birds. Most of the flea species in the Caucasian fauna (88 out of 155) parasitize rodents, 51 species of which are permanent hosts of different flea species; 13 flea species occur on 11 species of insectivores; 13 flea species, on 13 species of chiropterans; 14 flea species, on 20 species of carnivores. Only 2 flea species parasitize artiodactyles. 54 species of birds are permanent hosts of 23 species of fleas from 4 genera in the Caucasus. Ten types of ranges of flea species are distinguished; host associations of the Caucasian flea species from these groups are discussed. The greatest numbers of hosts from the families Cricetidae, Muridae, and Sciuridae are associated with fleas with Euro-Asian (extra-Siberian), European, Turanian, and Iranian ranges. Soricidae are known as hosts of flea species with European and Euro-Turanian ranges. Four major groups of flea taxa are represented in the Caucasian fauna. The distribution of the first group is determined by the influence of the palaeofauna of the ancient European continent in the early Cenozoic; that of the second group, by the influence of the fauna of the ancient Asian continent during the Paleogene and part of the Neogene; the third, by the influence of the fauna of southern Europe starting with the Miocene. The fourth group comprises the species which immigrated from northern Europe and Asia in the Late Neogene (2–3 mln years ago).     

Adaptations of fleas (Siphonaptera) to parasitism

The paper deals with peculiarities of flea structure determined by their parasitism on mammals and birds. On the basis of the data on diversity of morphological characters, the leading role of structures of the frontal and nototrochanteral complexes in the adaptive evolution of Siphonaptera is substantiated. Peculiarities of the pulicoid, ischnopsylloid, palaeopsylloid, and generalized morphological types are analyzed together with examples of narrow morphological specializations. Distribution of fleas of these morphological types over five groups of hosts differing in the degree of mobility and association with nests and burrows is also analyzed.     

The longevity of Leptopsylla segnis fleas (Siphonaptera: Leptopsyllidae)

In experiments, the mean life duration of fleas Leptopsylla segnis on white mice (abundance of fleas within natural limits, up to 10 fleas per mouse) was 22.7 days in females and 18.8 day in males. Maximum life duration was 51 and 37 days respectively. In cases, when the initial numbers of fleas were 20 and 28-34 fleas, the duration of life was decreased. The maximum limit decreased greater than the mean duration of life. A survival dynamics of fleas depended upon the flea number. It was found out, that in cases of high abundance of fleas in the beginning of experiments, the mortality rate of males was lower than in females. During the stay on a host the fleas lost gradually an ability to endure a starvation. Possible mechanisms of the regulation of flea abundance are discussed.     

A morphologic analysis of digestion in Leptopsylla segnis (Siphonaptera: Leptopsyllidae) fleas

Changes in the ultrastructure of cells of the intestinal epithelium during the digestion of one blood portion were traced in the fleas L. segnis. It is shown that alongside with the cavity digestion take place elements of intracellular digestion. Hypothetic scheme of the digestive cell functioning is given.     

Myrtlemiris,a new genus and new species of Australian plant bugs (Insecta: Heteroptera: Miridae): systematics,phylogeny and host associations

A new Australian genus of Orthotylinae, Myrtlemiris Cheng, Mututantri & Cassis gen.n. , is described, with nine included species described as new to science (M. agnew sp.n. , M. astartephila sp.n. , M. meanarra sp.n. , M. newmanensis sp.n. , M. rubrocuneatus sp.n. , M. russulatus sp.n. , M. silveirae sp.n. , M. tesselatus sp.n. , M. yalgoo sp.n. ). A phylogenetic analysis based on 39 morphological characters is presented for all Myrtlemiris species and 6 outgroup taxa. This analysis establishes Myrtlemiris as monophyletic, defined by a broad apophysis on the left paramere. A key to species is provided and diagnostic characters are illustrated. Myrtlemiris is endemic to southwest Western Australia. Host plants for Myrtlemiris species are near restricted to the myrtaceous tribe Chamelaucieae.     

Peculiarities of thoracic and abdominal combs of fleas (Siphonaptera)

The structure of pseudosetae, spinelets, and spines of combs (ctenidia) was studied by means of light and SE microscopy in 80% of genera and subgenera of the World fauna. It is found out that peculiarities of ctenidiae in the prothorax and in tergites of the abdomen are characteristics of families and infraorders of fleas. Some characters of ctenidiae found in certain flea genera are reductions and apparently caused by habitation in some extremal conditions. An absence of ctenidiae in the unfraorder Pulicomorpha is compensated by more developed posterior margin of prothorax and general abbreviation of all thoracal segments. Reasons of ctenidiae absence, which is observed in certain genera of the infraorders Ceratophyllomorpha, Pygiopsyllomorpha and Hystricopsillomorpha associated with the same hosts, is not clear. It is confirmed, that distance between ctenidiae in different flea species associated with the same species host species, however it is recovered, that this distance correlates with the diameter of most thin hair of host. In some flea species the distance between ctenidia spices in females is larger, than in males. It is found, that sexual dimorphism by this character may not be expressed in certain species of closely related species group of fleas. It is suggested that ctenidiae were present even in the common ancestor of fleas. The hypothesis on origin of spines and pseudosetae from setae of the posterior walls of toracal and abdominal segments in the common ancestor of fleas is proposed.     

On the fleas and louse (Insecta: Siphonaptera and Anoplura) of the garden dormouse,Eliomys quercinus (L. 1766) in Belgium

More than 3500 fleas, collected in southern Belgium, from 54 garden dormice (Eliomys quercinus) and from 58 nests of the rodent, were examined. Ceratophyllus s. sciurorum seems to be the only regular and abundant flea on the garden dormouse and in its nest whereas Myoxopsylla laverani is quite uncommon (5/31 infested animal and 11/52 infested nests). In comparison, 96 garden dormice were checked in France. M. laverani is present on nearly every infested animal (61/66). Other fleas were also found, some mammal-fleas (Megabothris turbidus, Hystrichopsylla talpae, several Ctenophthalmus spp.) and great numbers of bird-fleas (Ceratophyllus gallinae and Dasypsyllus gallinulae) because the dormouse-nests where the fleas were taken were built on old tit-nests (Parus spp). Finally, Schizophthirus pleurophaeus, a louse, was collected for the first time in Belgium.     

Ectoparasitic "jacks-of-all-trades": relationship between abundance and host specificity in fleas (Siphonaptera) parasitic on small mammals

Animal species with larger local populations tend to be widespread across many localities, whereas species with smaller local populations occur in fewer localities. This pattern is well documented for free-living species and can be explained by the resource breadth hypothesis: the attributes that enable a species to exploit a diversity of resources allow it to attain a broad distribution and high local density. In contrast, for parasitic organisms, the trade-off hypothesis predicts that parasites exploiting many host species will achieve lower mean abundance on those hosts than more host-specific parasites because of the costs of adaptations against multiple defense systems. We test these alternative hypotheses with data on host specificity and abundance of fleas parasitic on small mammals from 20 different regions. Our analyses controlled for phylogenetic influences, differences in host body surface area, and sampling effort. In most regions, we found significant positive relationships between flea abundance and either the number of host species they exploited or the average taxonomic distance among those host species. This was true whether we used mean flea abundance or the maximum abundance they achieved on their optimal host. Although fleas tended to exploit more host species in regions with either larger number of available hosts or more taxonomically diverse host faunas, differences in host faunas between regions had no clear effect on the abundance-host specificity relationship. Overall, the results support the resource breadth hypothesis: fleas exploiting many host species or taxonomically unrelated hosts achieve higher abundance than specialist fleas. We conclude that generalist parasites achieve higher abundance because of a combination of resource availability and stability.     

Association of Bartonella with the fleas (Siphonaptera) of rodents and bats using molecular techniques.

Bartonella spp. are putatively vector-borne bacterial agents of humans and animals. Fleas have been incriminated as vectors of Bartonella spp. and are suspected of transmitting Bartonella of rodents and bats, but some of these Bartonella spp. have not yet been directly detected in wild caught fleas. We report the molecular detection of Bartonella tribocorum, Bartonella vinsonii subsp. vinsonii, and two novel genotypes of Bartonella from the fleas Xenopsylla cheopis, Ctenophthalmus pseudagyrtes, Sternopsylla texanus, or Orchopeas howardi.