A new species of flea in the genus Ctenophthalmus (Siphonaptera: Hystrichopsyllidae)]

A new species, Ctenophthalmus (Euctenophthalmus) parthicus sp. n., is described from social vole (Microtus socialis Pallas) from four localities of the West Kopetdag Mountains of Turkmenia. The new species is close to C.(E.) secundus Wagner and C.(E.) congener nadimi Farhang-Azad. It differs from males of the other known species by the following characters. The movable process has an infra-acetabular process whose length is the same as the height of its supra-acetabular portion. The movable process has the straight front margin, right anterior apical angle. The anterior part of the dorsal margin of the movable process is elevated, the hind part is slightly concave. The posterior apical angle of the movable process is cut. The hind margin of the movable process is convex. The apex of the distal arm of sternum IX is straight, not oblique. The female differs by the following peculiarities. Sternum VII has a well developed dorsal lobe below which there is a smaller rounded lobe and a distinct small ventral process. Unciform sclerotization of tergum VIII (or the place of connection between tergum VIII and its internal lobe) resembles an arc. The front margin of the internal lobe of tergum VIII is not sclerotized. The bursa copulatrix is as long as the dorsal spines of pronotum.     

Ctenophthalmus rettigi Rothschild, 1908 (Hystrichopsyllidae) fleas of Mesocricetus

Fleas of Ctenophthalmus rettigi Rothschild, 1908 (12 females, 12 males) collected in 1980 and 1982 in the northern Caucasus in the Levashi District of Dagestan not far from the village of Urma were referred by the authors to the nominative subspecies described from Romania. According to their taxonomic characters fleas of this species, collected in different places of Transcaucasia, are also referred to the nominative subspecies and not to C. rettigi smiti Klein, 1962, as before (Rostigaev, 1967; Tiflov, Skalon, Rostigaev, 1977 and others). The ways of distribution of hosts of C. rettigi fleas are suggested.     

Observations of fleas of small mammals at the Gran Paradiso National Park (Italian Occidental Alps)]

The Siphonaptera of small mammals (nearly 200 rodents, insectivora and mustelids) of the Parco Nazionale del Gran Paradiso (Western Italian Alps) have been collected and studied during the years 1973-75. All the animals have been captured at altitudes ranging from 1570 to 2400 m during different seasons. Twelve genera and sixteen species have been identified, namely: Chaetopsylla (C.) homoea homoea from Mustela erminea; Hystrichopsylla (H.) talpae talpae from Clethrionomys glareolus; Rhadinopsylla (A.) integella integella from Clethrionomys glareolus and Microtus nivalis; Ctenophtalmus (C.) agyrtes verbanus from Pitymys multiplex (collected by Beaucournu); Ctenophthalmus (C.) solutus solutus from Apodemus flavicollis and Apodemus sylvaticus; Ctenophthalmus (Medioctenophthalmus) nivalis nivalis from Clethrionomys glareolus, Microtus nivalis and Pitymys multiplex; Doratopsylla dasycnema cuspis from Sorex araneus and Clethrionomys glareolus; Palaeopsylla soricis rosickyi from Sorex araneus; Leptopsylla segnis from Apodemus sylvaticus and Mus musculus; Peromyscopsylla bidentata bidentata from Clethrionomys glareolus and Microtus nivalis; peromyscopsylla fallax from clethrionomgs glareous; Amphipsylla sibirica ssp. from clethrionomys glareolus and microtus nivalis; Malaraeus (Amalaraeus), penicilliger kratachvili from Clethrionomys glareolus, Microtus nivalis and Mustela erminea; Myoxopsylla laverani from Eliomys quercinus; Callopsylla saxatilis from Apodemus flavicollis, Microtus nivalis and Mustela erminea. Species of fleas not yet described in Italy are: Chaetopsylla (C.) homoea homoea; Rhadinopsylla (Actenophthalmus) mesa; Ctenophthalmus (Medioctemophthalmus) nivalis nivalis; Callopsylla saxatilis. The genus Callopsylla is identified for the first time in Italy. New identification of hosts for the species of fleas already described in Italy are: for Rhadinopsylla (Actenophthalmus) integella integella: Clethrionomys glareolus; for Ctenophthalmus (C.) solutus solutus: Apodemus flavicollis and Apodemus sylvaticus. All the 15 male specimens of M. laverani from E. quercinus captured in the Parco Nazionale del Gran Paradiso have characters more similar to M. l. traubi than to M. l. laverani: only one long and a much shorter spine in the superior half of the movable process, a distinct tooth in the anterior margin of the movable half of the movable process, a distinct tooth in the anterior margin of the movable process, crochets of phallosome shorter and more gradually tapered, apex of fixed process very acuminated. To the contrary the shape of the movable process is similar to that of M. l. laverani. A point of particular interest is to be found also in 2 specimens of Amphypsilla of the sibirica group, respectively collected from Mustela erminea and Microtus nivalis. They have a very atypical distribution of the spine in an abnormally shaped movable process: the reasons of the abnormality are due to castration, probably of parasitic origin (absence of phallosome, tendons, etc.).     

Two new Ctenophthalmus (Insecta: Siphonaptera: Ctenophthalmidae) from Tanzania

During a recent epidemiological study of Lushoto plague focus, some uncommon specimens of fleas or even totally new species were collected. In this paper, we describe one of those, Ctenophthalmus (Ethioctenophthalmus) teucqae n. sp. Microscopic observation of comparison specimens deposited at National History Museum (London) allows us to create a sub-species, C. (E.) teucqae shumeensis n. ssp.     

Life histories of Clethrionomys and Microtus (Microtinae)

Although there have been numerous life-history reviews of mammals at high taxonomic levels (e.g. among families within orders), there are far fewer studies at lower taxonomic levels (e.g. among species within genera). Data on adult weights, litter size, gestation length, neonate weight, age and weight at weaning, growth rate to weaning, maximum life span, and length of the breeding season were compiled from the literature on five species of Clethrionomys and 33 species of Microtus. Variability in litter size and male body weights was not significantly different when compared between cyclic and non-cyclic populations. Coefficients of variation were also calculated for the three species with the most data (C. gapperi, C. glareolus and M. pennsylvanicus ). These values showed that the amount of intraspecific variation differed among traits as well as among species. Gestation length was the most invariable of all traits and variation in adult weights, neonate weight, gestation length, and litter size had similar values to those reported for Peromyscus maniculatus. Five and eight traits differed among Clethrionomys and Microtus species, respectively. Differences in litter size, adult weights and length of the breeding season were common to both genera. Male weight, gestation length and neonate weight as well as length of the breeding season were different between genera. Very few traits covaried within C. gapperi, C. glareolus or M. pennsylvanicus. Similarly, few traits covaried among all Clethrionomys populations. However, among all Microtus populations and Microtus species, 11 and 12 correlations were significant. Many of the patterns found in Microtus involved positive relationships between female weight and some other trait. These patterns have also been found by broader surveys at higher taxonomic levels. Large species of Microtus had larger offspring, a greater litter size and occurred in short-season environments relative to small species of this genus.     

Size of the vomeronasal organ in wild Microtus with different mating strategies

Most studies on mammalian vomeronasal organ (VNO) have been on laboratory-bred animals. Our present study examines the VNO in wild-caught meadow voles (Microtus pennsylvanicus: n=16) and prairie voles (M. ochrogaster: n=15). These species vary in their mating strategies and degree of parental care by males. M. ochrogaster exhibits pair bonding and more paternal care compared to M. pennsylvanicus, a promiscuous species. We hypothesize that sexual dimorphism will occur in the promiscuous species based on previous studies which suggest that those who exhibit more aggressive or masculine behavior have larger VNOs. Our results support our original finding that VNOs are not different in size in wild Microtus spp. that vary in male parental tendencies. However, the present study also indicates that M. pennsylvanicus, the species exhibiting more disparate parental tendencies, exhibited larger VNOs in females than males. This is the reverse of previous findings on rats, and we hypothesize that this difference may be due to mate selectivity and/or maternal aggression.     

Seasonal Differences in Social Behavior among Adult and Juvenile Meadow Voles,Microtus pennsylvanicus

Seasonal differences in behavioral interactions between wild-caught adult and juvenile meadow voles, Microtus pennsylvanicus, were measured in paired encounters in a neutral arena. Seasonal differences existed in the adult-juvenile paired encounters. Early in the breeding season (May—Aug.) paired encounters between adult males and juvenile males were more agonistic than other adultjuvenile pairings. Late in the breeding season (Sep.—Dec.) adult female-juvenile male encounters were more agonistic than other adult-juvenile pairings. Odor preferences of juveniles were determined in a Y-maze olfactometer. Juveniles did not demonstrate seasonal differences in odor preference. Males preferred the odor of adult females to the odor of adult males or their own odor. Females preferred the scent of an adult male to the odor of an adult female, but did not show a preference between their own odor and the odor of an adult male or an adult female. The results are consistent with hypotheses that state in a promiscuous species, females should be philopatric, and males should disperse as a consequence of adult competition. The data suggest that agonistic behavior by adults may regulate juvenile dispersal and recruitment, and define the composition of overwintering groups.     

Ctenophthalmus harputus, a new Spalax flea from Turkey

ABSTRACT. Ctenophthalmus harputus sp.n. is described from the mole rat Spalax ehrenbergi Nehring collected near Elaziǧ city in eastern Turkey. This new flea species is classified in the Ctenophthalmus (Palaeo-ctenophthalmus) fissurus Wagner group. A key is given to the six species of Spalax fleas (Siphonaptera: Hystrichopsyllidae, Ctenophthalmus spp.) recorded from Turkey.     

Multi-male mating, probability of conception, and litter size in the prairie vole (Microtus ochrogaster)

We conducted a mating experiment in the laboratory using prairie voles, Microtus ochrogaster, to document that multi-male mating (MMM) can occur in this supposedly monogamous species and to test two hypotheses for the advantages of MMM in female mammals. The two hypotheses are that MMM (1) increases the probability of pregnancy and (2) increases litter size. We also tested the hypothesis that multiple copulations, rather than multiple partners, increases litter size and/or probability of pregnancy. Females were given a choice of mating with any of three males, each of which was tethered in a separate compartment. The mate choice bouts were recorded on videotape. We recorded the number of copulations and number of males with which females mated over a 24 h period. Litter size and probability of pregnancy were not significantly different for females that mated with one, two or three males. Increasing numbers of copulations, independent from the number of males, also did not increase litter size but did significantly increase the probability of pregnancy. MMM, at least in prairie voles, must serve some function other than increasing litter size and probability of conception.     

Influence of gonadal hormones on odours emitted by male meadow voles (Microtus pennsylvanicus).

Free-living male meadow voles (Microtus pennsylvanicus) emit odours that are attractive to females at the beginning, but not at the end, of the breeding season. The effect of gonadal hormones on female-attractant cues was examined in males born and reared in long (14 h light day-1) and short (10 h light day-1) photoperiods that simulate daylengths in the breeding and nonbreeding seasons, respectively. Gonadectomy affected the attractant properties of odours emitted by long photoperiod, but not short photoperiod, males. Long photoperiod females preferred odours of intact rather than those of gonadectomized long photoperiod males, and odours of gonadectomized long photoperiod males rather than those of intact short photoperiod males. Females did not show a preference between the odours of intact and castrated short photoperiod males. Gonadal hormone replacement in males affected female responses to the odours emitted by long photoperiod, but not short photoperiod, gonadectomized males. Long photoperiod females did not display a preference between odours of intact long photoperiod males and gonadectomized long photoperiod males treated with testosterone or oestradiol. We conclude that in spring and summer gonadal hormones increase attractiveness of male odours; this effect may require aromatization of testosterone to oestradiol. Substrates that control attractiveness of odour cues in male voles appear to be unresponsive to androgens during the nonbreeding season.     

Female-biased infection and transmission of the gastrointestinal nematode Trichuris arvicolae infecting the common vole, Microtus arvalis

Previous studies addressing the importance of host gender in parasite transmission have shed light on males as the more important hosts, with the higher transmission potential of males being explained by the fact that they often harbour higher parasite loads than females. However, in some systems females are more heavily infected than males and may be responsible for driving infection under such circumstances. Using a wild population of common voles (Microtus arvalis), we showed that females were more frequently infected by the intestinal nematode Trichuris arvicolae than males (i.e. prevalence based on the presence of eggs in the faeces) and that females were shedding greater numbers of parasite eggs per gram of faeces (EPG) than males. By applying an anthelmintic treatment to either male or female voles, we demonstrated that treating females significantly reduced parasite burdens (i.e. prevalence and EPG) of both male and female hosts, while treating males only reduced parasite burden in males. These findings indicate that in this female-biased infection system females play a more important role than males in driving the dynamics of parasite transmission.     

棕色田鼠探究行为对同种个体气味源反应格局的分析

通过观察非动情期的棕色田鼠对麻醉的同种个体身体气味源的探究行为 ,包括雄鼠对麻醉雄鼠和雌鼠的嗅闻、雌鼠对麻醉雄鼠和雌鼠的嗅闻 ,分析了棕色田鼠在社会探究中对不同气味源的反应格局。结果表明 ,棕色田鼠对同种个体肛殖区和面部的嗅闻频次及嗅闻持续时间最多 (P <0 0 5 ) ;对背部、腹部、肋部嗅闻的频次和持续时间较少。在对同一部位的嗅闻中 ,在嗅闻频次上 ,雄鼠对雄鼠的嗅闻、雌鼠对雌鼠的嗅闻以及雌鼠对雄鼠的嗅闻都显著多于雄鼠对雌鼠的嗅闻 (P <0 0 5 ) ;在嗅闻时间上 ,性别组合对同一部位的探究行为没有显著影响 ,但气味源与性别组合有交互作用 (P <0 0 5 ) ,影响探究行为。这些结果说明棕色田鼠的肛殖区和面部是重要的气味源 ,而且在对同一气味源的探究中存在性别差异。但在非动情期 ,异性间的探究并不总是高于同性间的探究     

Islands and the evolution of Microtus arvalis (Microtinae)

The widespread European vole species Microtus arvalis (Pallas) occurs in the British Isles only on Guernsey and various of the Orkney islands. The traditional explanation for this peculiar distribution has been that the island races are the sole relicts of a previously cosmopolitan form. This idea is not supported by the present study, in which population samples are compared with voles from a number of localities from Continental Europe. Using the frequencies of non-metrical skull variants as genetical markers, it emerged that although the Guernsey population ( Microtus arvalis sarnius ) was virtually indistinguishable from typical German specimens, and therefore likely to be a relict from the time when Guernsey was connected to France, the Orkney populations ( Microtus arvalis orcadensis ) formed a distinct group with affinities more to south Europe than elsewhere. It seems probable that arvalis was brought to Orkney by some of the earliest human colonizers about 4000 years ago, and then radiated to the different islands. It is argued that this manner of peripheral differentiation may be an important method of evolutionary change.     

Ctenopllhaimus (Ethioctrvophthalmus) kemmelberg n. sp. (Insecta: Siphonaptera: Ctenophthalmidae), a new flea from Tanzania and description of unknown small structures in the mecopteroids

We recently described two new taxa of Siphonaptera (Ctenophthalmus (Ethioctenophthalmus) teucqoe teucqaoe et C. (E.) teucqae shumeensis Laudisoit & Beaucournu, 2007) from Lushoto plague focus (West Usambara mountains, Tanzania). A new taxa is here being studied, Ctenophthalmus kemmelberg, an original flea, not only for its genitalia, but also for original structures appearing, and that have not been described yet, at our knowledge, in any Mecopteroid. These are visible in females only. We suggest the name "Teucq's organs" for those remarkable structures.     

Scent-marking behaviour by male prairie voles,Microtus ochrogaster,in response to the scent of opposite- and same-sex conspecifics

We conducted an experiment using the prairie vole (Microtus ochrogaster) to test predictions associated with the proposed functions of scent marking as a sexual attractant, in reproductive competition, and as a self-advertisement. We allowed an oestrous female, an anoestrous female, and an adult male to scent mark three portions of a clean substrate and then exposed a second male to this substrate for secondary marking. We did not support a sexual attraction hypothesis in that males did not place more scent marks in response to oestrous than anoestrous females. Similarly, we did not support a reproductive competition hypothesis in that males did not place more scent marks in response to marks of males than to those of females or bare substrate. Males did not overmark the scent of males or females and thus we did not support a scent-masking or scent-blending hypothesis. In that males deposited scent similarly in response to males, females, and on bare substrate, our results suggest that the frequency and placement of scent marks by males function primarily to advertise individual identity in an area.     

Alternative male reproductive tactics in a natural population of prairie voles <Emphasis Type="Italic">Microtus ochrogaster</Emphasis>

Alternative reproductive tactics have been described in male mammals, but little information exists regarding fitness benefits and whether males change tactics. Adult male prairie voles Microtus ochrogaster (Wagner, 1842) display alternative tactics described as resident and wanderer. Enclosure studies provide conflicting data concerning the relative success of each tactic and whether males display one tactic throughout adulthood. To characterize further residents and wanderers in this species, we examined data collected during 5 years of monitoring a natural population in Illinois, USA. We found that during the breeding period, wandering males survived longer, moved longer distances, and were more likely than residents to have scrotal testes. During the nonbreeding period, wandering and resident males differed only in whether or not they established residency. Data on sources and fates of resident and wandering males revealed that a substantial proportion of males switched tactics. Our estimate of the reproductive contribution of wandering males to the population, which is based on the premise that wandering males typically mate with single females, suggests that wanderers contribute 34–38% of young recruited during March through October and 4–12% in November, when single females are less common. Parentage studies in natural populations are necessary to test our estimates.     

Characteristics of tear proteins in the vole, Microtus arvalis

Tear proteins were detected by polyacrylamide gel electrophoresis in the vole, Microtus arvalis. The tear proteins were separated to 6 to 8 bands and the bands were divided to three regions on the anodic side. In the adult male vole, a male specific band (Vtp-1) was detected in the first region. The first region of adult female and immature voles contained two specific bands (Vtp-2, 3). In the castrated adult males or adult males injected with estrogen, the male specific hand, Vtp-1, disappeared and Vtp-2 and 3 bands appeared. In all castrated voles, the Vtp-1 band appeared and Vtp-2 and 3 bands disappeared after the administration of testosterone. Thus, sex hormone-dependent proteins are present in vole tears.     

X-Y chromosome synapsis and recombination in 3 vole species of Asian lineage of the genus Microtus (Rodentia: Arvicolinae)

The pattern of X-Y chromosome pairing in male meiosis is an important taxonomic feature of grey voles of the genus Microtus. Asynaptic sex chromosomes have been found in the majority of species of the Palearctic phylogenetic lineage of this genus, while normal X-Y synapsis has been observed in the species of subgenus Pallasiinus belonging to the Asian phylogenetic lineage. We analyzed sex chromosome pairing and recombination in M. maximowiczii, M. mujanensis and M. fortis which also belong to the Asian phylogenetic lineage (subgenus Alexandromys). Using immunostaining for the proteins of the synaptonemal complex (SCP3) and recombination nodules (MLH1) we demonstrated that X and Y chromosomes of these species paired and recombined in a short subtelomeric region. This indicates that the sex chromosomes of these species retain an ancestral fully functional pseudoautosomal region, which has been lost or rearranged in the asynaptic species of the genus Microtus.     

The effects of mate removal on pregnancy success in prairie voles (Microtus ochrogaster) and meadow voles (Microtus pennsylvanicus).

The effects of removing the stud male have not been controlled in many studies relating pregnancy block to the presence of an unfamiliar male. We examined the effects of removing the male on pregnancy success in prairie voles and meadow voles, two species that differ in degree of paternal investment. Whereas prairie vole males provide extensive care to offspring and accelerate pup development, meadow vole males display little or no care and delay development of pups. We predicted that removal of the stud male would decrease pregnancy success in prairie voles and either have no effect or increase success in meadow voles. In experiment 1, females were in male-induced estrus, and their mates were either left with them or were removed 4 h, 1 day, 2 days, or 8 days after mating. In experiment 2, females were in postpartum estrus, and their mates were either left with them or were removed 1 day, 2 days, or 8 days after birth of their first litter. Removal of the male soon after mating in postpartum estrus decreased pregnancy success in prairie voles and increased success in meadow voles. Thus, although removal of the stud male influenced litter production, the direction of the effect varied with species.