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.     

Fertility changes in Leptopsylla segnis (Siphonoptera: Leptopsyllidae) fleas depending on the duration of their preliminary contact with the food source

In experiments the fecundity of Leptosylla segnis was depended upon duration of the preliminary contact of the host (white mouse) with fleas of the same species. As the duration of the contact was promoted the daily mean number of eggs per female at first (at time of contact from 1 to 6 days) increased, then (at time of contact 7-12 days) declined and decreased below original level at 13-30 days of contact. It is supposed that observed changes in fleas fecundity were connected with the immune reactions of the host to the bites of insects.     

The flea genus Sigmactenus (Siphonaptera: Leptopsyllidae): a new species from timor and new material from New Guinea and the Philippines

Both sexes of Sigmactenus timorensis n. sp. are described from Rattus tanezumi and Rattus exulans collected in West Timor, Indonesia. The true host presumably is a native murine rat such as the extant, endemic Rattus timorensis or 1 of several extinct, endemic Timorese rats. Analyses of new collections of Sigmactenus cavifrons and Sigmactenus toxopeusi from New Guinea demonstrate that these fleas show considerable morphological variation. We propose that they represent a single species with the name S. toxopeusi having priority. New collections of Sigmactenus werneri from the Philippines expand the known hosts and geographical distribution of this flea.     

Susceptibility of the cat flea (Siphonaptera: Pulicidae) to pyrethroids

Adult cat fleas, Ctenocephalides felis felis (Bouché), from two laboratory colonies (one originating in California and one from Florida) were exposed to residues of eight pyrethroids to compare their susceptibilities. The Florida strain was more tolerant than the California strain, with 6.8-, 5.2-, and 4.8-fold tolerance to cyfluthrin, cypermethrin, and fluvalinate, respectively. The Florida strain showed less than 3-fold tolerance to the other five insecticides (permethrin, tralomethrin, d-phenothrin, resmethrin, and fenvalerate). Overall, the pyrethroids were ineffective against the Florida strain.     

Water uptake in the cat flea Ctenocephalides felis (Pulicidae: Siphonaptera)

To counteract water loss due to excretion, cuticular transpiration and respiration, various groups of arthropods have developed mechanisms for active uptake of water vapor from unsaturated air. In this study, active uptake capabilities and water loss rates were examined in the various developmental stages of the cat flea, Ctenocephalides felis. To determine critical equilibrium humidity, the lowest relative humidity at which active water uptake can occur, pre-desiccated immature and adult fleas were placed in a series of humidity regimes ranging from 44 to 93% RH. Active uptake occurred in larval stages at relative humidities above 53% and in pre-pupae at 75-93% RH. Pupae and adults did not demonstrate active uptake at any humidity. Optimal uptake for larvae occurred between 20 and 30 degrees C. When placed over Drierite (<10% RH), larval and adult stages demonstrated a higher rate of water loss than pre-pupal and pupal stages. Active water uptake is necessary to ensure proper development of the larvae of C. felis. Active uptake ceases after the larval-pupal ecdysis and it appears that adults have lost the ability to actively uptake water.     

蚤雌雄同体畸形一例(昆虫纲:蚤目)

报道蚤雌雄同体畸形一例。     

Patterns of formation of the flea (Siphonaptera) fauna in the Caucasus

Fleas of the Caucasus belong to 155 species of 40 genera, constituting 17% and 43% of the species and generic composition of the Palaearctic fauna, respectively. The Caucasian fauna includes 23 endemic species but no endemic genera or subgenera. In the number of species, the Caucasian fauna is similar to that of the Mediterranean Subregion and is significantly poorer than the faunas of the Euro-Siberian (by 2.2 times) and Irano-Turanian (by 1.7 times) Subregions. Based on taxonomic diversity, we can propose a hypothesis on the West and East Palaearctic sources of the Caucasian fauna. The West Palaearctic source has determined the distribution of pulicomorph fleas of the families Pulicidae and Coptopsyllidae from Africa, on the one hand, and of fleas of the genera Ctenopthalmus and Palaeopsylla from Europe, on the other hand. Fleas of the Holarctic genera, such as Ceratophyllus and Megabothris, entered the Caucasus by the north Asian route; fleas of the genera Neopsylla, Rhadinopsylla, and Hystrichopsylla migrated to the Caucasus from east and central Asia by the south Asian route, through Middle and Western Asia.     

The flea genus Sigmactenus (Siphonaptera: Leptopsyllidae): three new taxa from Sulawesi, updated identification key, and distribution map for all known species and subspecies

One new species and two new subspecies of fleas are described. These are S. sulawesiensis n. sp. from North and Central Sulawesi, S. alticola pilosus n. ssp. from Central Sulawesi, and S. alticola crassinavis n. ssp. from North Sulawesi. All three of these new taxa are ectoparasites of native, endemic murine rodents. Two of the new taxa, S. sulawesiensis and S. alticola crassinavis, coexist on the same mountain, Gunung Moajat, in North Sulawesi. The related S. alticola alticola, which becomes the nominate subspecies, parasitises the murine rodent Maxomys alticola in northern Borneo (Sabah) and it is hypothesized that Sigmactenus first colonized Sulawesi as an ectoparasite of ancestral Maxomys, or perhaps Rattus, as these murines dispersed from southeast Asia to Sulawesi; 15 endemic murine rodent species belonging to these two genera are known to currently inhabit Sulawesi. An identification key and distribution map are included for all known species and subspecies of Sigmactenus. In addition to the three new taxa and S. a. alticola, these include: S. celebensis from South Sulawesi, S. timorensis from Timor, S. toxopeusi from New Guinea, and S. werneri from the Philippines (Mindanao and Negros).     

Classification of the flea families (Siphonaptera): II. Family Hystrichopsyllidae (Part 3)

Morphological characters and their diversity in the Afrotropical subfamilies Dinopsyllinae and Listropsyllinae, and the Holarctic subfamily Anomiopsyllinae are evaluated. Three centers had the major significance in the formation of the family Hystrichopsyllidae: the South American (extra-Caribbean), Afro-European, and North American and Asian ones. One more center may have been located in Australia but its fauna has become largely extinct or remains unknown. The origin of a number of tribes of the subfamilies Hystrichopsyllinae and Doratopsyllinae is associated with the South American center; the origin of subgenera of the subfamily Ctenophthalminae as well as the subfamilies Listropsyllinae and Dinopsyllinae, with the Afro-European center; and the origin of the subfamilies Neopsyllinae, Rhadinopsyllinae, Anomiopsyllinae, Stenoponiinae, and Liuopsyllinae, with the North American and Asian center. Distribution of the subfamilies Doratopsyllinae and Hystrichopsyllinae sheds light on the initial stages of formation of the family Hystrichopsyllidae.     

Classification of the flea families (Siphonaptera): II. Family Hystrichopsyllidae (part 2)

Morphology of the flea family Hystrichopsyllidae is considered. The subfamilies Stenoponiinae, Neopsyllinae, Doratopsyllinae, and Ctenophthalminae are distinguished. In all, 148 states of the characters of the head, thorax, modified abdominal segments, and aedeagus have been analyzed within the family Hystrichopsyllidae and the whole order Siphonaptera as well.     

Classification of the flea families (Siphonaptera): II. Family hystrichopsyllidae (Part 4)

Distribution of the ancestral, homoiologous, and convergent character states over the tagmata and morpho-functional complexes of the flea body in nine subfamilies of the Hystrichopsyllidae is analyzed. The analysis is based upon the states of 111 characters of 73 structures of 3 tagmata in the adult flea body. The homoiologous states (those arising in parallel in close flea infraorders) comprise 35%, the ancestral (the least specialized) ones, 16%, and the convergent ones, 13% of the total number of character states of all the 10 types. The greatest numbers of the ancestral character states in the Hystrichopsyllidae are found in the mesothorax (22.8%) and aedeagus (21.1%); the metathorax reveals 19.3%, and the head, 17.5% of the ancestral character states. The greatest number of homoiologous character states, 34.1% of the total number, is observed in the mesothoracal segment. Smaller fractions of the homoiologous character states are found in the head (24.6%) and metathorax (17.5%). Those character states which arise in the phylogenetically remote infraorders are considered convergent. The greatest number of convergent character states in the Hystrichopsyllidae (55.1%) is observed in the structure of the aedeagus.     

Classification of the flea families (Siphonaptera): I. Family Hystrichopsyllidae (Part 5)

Based on analysis of homologous character states and considering the molecular-biological data (Whiting et al., 2008), phylogenetic relationships of the tribes and subfamilies of the family Hystrichopsyllidae are discussed. In some cases, homologous states of the skeleton characters mark the clades revealed by the moleculargenetic analysis, but are shared by taxa from other clades. In contrast to the molecular-genetic data, morphological characters indicate the phylogenetic integrity of the family Hystrichopsyllidae. Morphological characters depict the subfamily Anomiopsyllinae as a monophyletic taxon (having synapomorphic states of the metaphragma, metasternite, and the mesosternal apodeme) closest to the subfamilies Neopsyllinae and Rhadinopsyllinae. The subfamilies Neopsyllinae, Rhadinopsyllinae, and Stenoponiinae have a non-thickened metasternite; the former two subfamilies also have in common a similar structure of articulation of the digitoid with the clasper, type of the metaphragma modification, and the presence of the sclerotized central sclerite. Homologous modifications of the metaphragma are also present in fleas of the subfamily Stenoponiinae. Close to this group are the subfamily Hystrichopsyllinae whose representatives also possess non-thickened metasternal apodemes, and the subfamily Listropsyllinae with its frontal sclerotized tubercle being a specialized modification of the frontal sclerotized fold. A specific feature shared by fleas of the subfamilies Hystrichopsyllinae and Listropsyllinae is the presence of the metasternal furca with high sharp processes and a high medial ridge. The closeness of these taxa is supported by the results of molecular-genetic analysis. The subfamilies Doratopsyllinae and Ctenophthalminae (tribes Ctenophthalmini and Carterettini) are united by the type of the attachment of the mesopleural rod to the special ridge at the upper margin of the mesopleuron. According to the molecular-genetic data, the tribe Neotyphloceratini is related to these subfamilies, even though its members have no ridge on the mesopleuron. The similarity in the structure of the furca (the presence of high dorsal processes with rounded apices and a high median ridge) and in the length ratio of the fulcrum lobes relates the subfamilies Ctenophthalminae and Dinopsyllinae.     

Classification of flea families (Siphonaptera): I. Family Hystrichopsyllidae (first part)

A contribution is made to the previously elaborated classification of the order Siphonaptera (Medvedev, 1994, 1998). Host-parasite associations, geographical distribution, and morphology of the family Hystrichopsyllidae (sensu Hopkins and Rothschild, 1962, 1966) in comparison with other flea families are analyzed together with a position of the family within the infraorder Hystrichopsyllomorpha. The presence of two spermathecae, frequently used as a taxonomic character, is a character insufficient for the basic phylogenetic reconstructions, e.g., establishment of close relationship between the families Coptopsyllidae and Macropsyllidae or the tribes Ctenopariini and Hystrichopsyllini, because this character is a plesiomorphy of the order Siphonaptera. The subfamily Hystrichopsyllinae (sensu Hopkins and Rothschild, 1962) is characterized by a large number of morphological features which can be considered as plesiomorphic characters of the family Hystrichopsyllidae as a whole. The subfamily Hystrichopsyllinae should be restricted to the tribes Ctenopariini and Hystrichopsyllini. The family Macropsyllidae possesses a unique structure of the ctenidia and some other structures. It should be treated as a group closely related to Hystrichopsyllidae. The family Coptopsyllidae demonstrates another trend in the evolution of the head, thorax, and abdomen.     

Age-dependent flea (Siphonaptera) parasitism in rodents: a host's life history matters

We studied age-dependent patterns of flea infestation in 7 species of rodents from Slovakia (Apodemus agrarius, A. flavicollis, A. sylvaticus, A. uralensis, Clethrionomys glareolus, Microtus arvalis, and M. subterraneus). We estimated the age of the host from its body mass and expected the host age-dependent pattern of flea abundance, the level of aggregation, and prevalence to be in agreement with theoretical predictions. We expected that the mean abundance and the level of aggregation of fleas would be lowest in hosts of smallest and largest size classes and highest in hosts of medium size classes, whereas pattern of variation of prevalence with host age would be either convex or asymptotic. In general, mean abundance and species richness of fleas increased with an increase in host age, although the pressure of flea parasitism in terms of number of fleas per unit host body surface decreased with host age. We found 2 clear patterns of the change in flea aggregation and prevalence with host age. The first pattern demonstrated a peak of flea aggregation and a trough of flea prevalence in animals of middle age classes (Apodemus species and C. glareolus). The second pattern was an increase of both flea aggregation and flea prevalence with host age (both Microtus species). Consequently, we did not find unequivocal evidence for the main role of either parasite-induced host mortality or acquired resistance in host age-dependent pattern of flea parasitism. Our results suggest that this pattern can be generated by various processes and is strongly affected by natural history parameters of a host species such as dispersal pattern, spatial distribution, and structure of shelters.     

Circadian rhythm of cat flea (Siphonaptera: Pulicidae) locomotion unaffected by ultrasound

Cat fleas, Ctenocephalides felis (Bouché), had a circadian rhythm of locomotion that peaked during the last 2 h of the photophase and declined to a lower level that was maintained throughout the scotophase. Activity was lowest during the first 8 h of photophase. The circadian rhythm of these fleas was not affected by an ultrasonic pest control device.     

Taxonomic composition and zoogeographic characteristics of the flea fauna (Siphonaptera) of Russia

255 species and 59 subspecies of fleas from 55 genera of 7 families are known from Russia, which is 30% of the Palaearctic fauna. Additionally, over 187 species of 47 genera from 7 families are known from the neighboring territories of Central and Southern Europe, Transcaucasia, Kazakhstan, Middle Asia, Mongolia, Northeast China, and Japan. 13 species of 12 genera are known only from Russia. Noteworthy is the low percent of endemic species (not more than 4%) and genera (one genus) in the Russian fauna. The principal centers of taxonomic diversity in the Palaearctic, including many endemic species and genera, lie in the Eastern Asian, Central Asian, and Turano-Iranian Subregions, outside Russia and the Euro-Siberian Subregion. The bulk of the Russian fauna is formed by the species and genera of the three largest flea families: Hystrichopsyllidae, Ceratophyllidae, and Leptopsyllidae. The family Ceratophyllidae has the greatest number of genera in the Russian fauna, and Hystrichopsyllidae, the greatest number of species. Western (Western and Western-Central Palaearctic; 84 species from 41 genera of 7 families) and Eastern (Central-Eastern and Eastern Palaearctic; 78 species from 42 genera of 6 families) species are nearly equally represented in the Russian fauna.