Helminths of sympatric black-tailed jack rabbits (Lepus californicus) and desert cottontails (Sylvilagus audubonii) from the high plains of eastern New Mexico

Thirty-five desert cottontails (Sylvilagus audubonii) and 35 black-tailed jack rabbits (Lepus californicus), occurring sympatrically near the Clovis-Portales area of eastern New Mexico were infected with four species of Eucestoda (adults of Raillietina salmoni and Raillietina selfi, larvae of Taenia pisiformis and Taenia serialis). Raillietina salmoni and T. pisiformis more commonly infected S. audubonii. Raillietina selfi was found in near equal prevalence in both host species. Taenia serialis was recovered only from L. californicus. Thus, three of the four helminth species were shared by both lagomorphs (Jaccard's coefficient = 75). Female hosts were most heavily infected with R. selfi and Taenia serialis.     

Biology of Cuterebra lepusculi Townsend (Diptera: Cuterebridae) in cottontail rabbits in Idaho

Cuterebra lepusculi Townsend parasitize cottontail rabbits (Sylvilagus nuttallii) in southern Idaho. Peak parasitism was 69% in mid-September. Mean development time in the host was 27 days. The species is univoltine in Idaho. Partially developed larvae were transferred from freshly killed to living hosts and the resulting larvae matured normally. Developing pupae were cooled or warmed to retard or speed development and synchronize adult emergence.     

Spirochetes in mammals and ticks (Acari: Ixodidae) from a focus of Lyme borreliosis in California

In northern California, antibodies to Borrelia burgdorferi were detected in 58 of 73 (79%), and spirochetemias in one of 26 (4%) black-tailed jackrabbits (Lepus californicus californicus), by indirect and direct immunofluorescence, respectively. Five species of ticks (Dermacentor occidentalis, D. parumapertus, Ixodes neotomae, I. pacificus, and Haemaphysalis leporispalustris) were collected from rabbits. Two of these species of ticks were found to contain spirochetes; two of 10 (20%) I. neotomae and two of 174 (1%) H. leporispalustris. A strain of B. burgdorferi was recovered from I. neotomae. One infected H. leporispalustris female passed spirochetes via eggs to about 67% of her progeny. The widespread distribution of the black-tailed jackrabbit, its infestation by at least four ticks (D. occidentalis, D. parumapertus, I. neotomae, and I. pacificus) known to be infected naturally with B. burgdorferi, and the high prevalence of spirochetal antibody in this lagomorph suggest that it might be useful as a sentinel for surveillance of Lyme borreliosis. Spirochetes were detected in 15% of 40 Columbian black-tailed deer (Odocoileus hemionus columbianus) by direct immunofluorescence bound with a Borrelia-specific monoclonal antibody (H9724), but not with a monoclonal antibody (H5332) specific for B. burgdorferi. The geographical overlap of different borreliae in ticks that bite wildlife such as deer may confound spirochetal serosurveys, and underscores the need for more specific serologic tests than those currently available.     

Eimeria (Protozoa: Eimeriidae) of the Cottontail Rabbit Sylvilagus audubonii in Northeastern Colorado, with Descriptions of Three New Species

SYNOPSIS. All of 100 cottontail rabbits Sylvilagus audubonii were found to be infected with 1-6 species of Eimeria. Three new species, E. audubonii, E. neoirresidua and E. poudrei are described from this host. Sub-spherical oocysts of E. audubonii average 21.2 by 17.1 μ; polar body, micropyle, oocyst residuum and sporocyst residuum are all absent; ellipsoidal sporocysts average 12.9 by 5.8 μ. Ovoid to ellipsoidal oocysts of E. neoirresidua average 25.7 by 17.9 μ; polar body and oocyst residuum are absent; micropyle and sporocyst residuum are present; ellipsoidal sporocysts average 14.5 by 6.4 μ. Ovoid to ellipsoidal oocysts of E. poudrei average 26.0 by 18.1 μ; polar body is lacking; micropyle, oocyst residuum and sporocyst residuum are present; ellipsoidal sporocysts average 14.4 by 6.4 μ. Three species of Eimeria previously described in the literature, E. maior Honess, 1939, E. media form honessi Carvalho, 1943 and E. environ Honess, 1939 are redescribed. A detailed structural and statistical analysis of each species is presented with at least 200 sporulated oocysts measured in each instance. A host list and a key to the Eimeria of cottontails is given. The use of detailed studies of oocyst size and structure as a tool for specific diagnosis of the Eimeria of cottontails is discussed.     

Absence of insect juvenile hormones in the American dog tick,Dermacentor variabilis (Say) (Acari:Ixodidae), and in Ornithodoros parkeri Cooley (Acari:Argasidae)

Synganglia, salivary gland, midgut, ovary, fat body and muscle alone and in combination from the ixodid tick, Dermacentor variabilis (Say), or the argasid tick, Ornithodoros parkeri Cooley, were incubated in vitro in separate experiments with L-[methyl-(3)H]methionine and farnesoic acid or with [1-(14)C]acetate. Life stages examined in D. variabilis were 3 and 72 h old (after ecdysis) unfed nymphs, partially fed nymphs (18 and 72 h after attachment to the host), fully engorged nymphs (2 d after detachment from host), 3 and 72 h old (after eclosion) unfed females, partially fed unmated females (12-168 h after attachment to host) and mated replete females (2 d after detachment from the host). Those from O. parkeri were third and fourth stadium nymphs and female O. parkeri, 1-2 d after detachment. Corpora allata from Diploptera punctata, Periplaneta americana and Gromphadorina portentosa were used as positive controls in these experiments. No farnesol, methyl farnesoate, JH I, JH II, JH III, or JHIII bisepoxide was detected by radio HPLC from any tick analysis while JH III, methyl farnesoate, and farnesol were detected in the positive controls. To examine further for the presence of a tick, insect-juvenilizing agent, Galleria pupal-cuticle bioassays were conducted on lipid extracts from 10 and 15 d old eggs, unfed larvae (1-5 d after ecdysis), unfed nymphs (1-7 d after ecdysis), and partially fed, unmated female adults (completed slow feeding phase) of D. variabilis. Whole body extracts of fourth stadium D. punctata and JH III standard were used as positive controls. No juvenilizing activity in any of the tick extracts could be detected. Electron impact, gas chromatography-mass spectrometry of hemolymph extracts from fed, virgin (forcibly detached 7 d after attachment) and mated, replete (allowed to drop naturally) D. variabilis and fully engorged (1-2 d after detachment) O. parkeri females also failed to identify the common insect juvenile hormones. The same procedures were successful in the identification of JH III in hemolymph of fourth stadium D. punctata. Last stadium nymphal (female) O. parkeri implanted with synganglia from second nymphal instars underwent normal eclosion to the adult. The above studies in toto suggest that D. variabilis and O. parkeri do not have the ability to make the common insect juvenile hormones, and these juvenile hormones do not regulate tick metamorphosis or reproduction as hypothesized in the literature.     

Wild turkey (Meleagris gallopavo) as a host of ixodid ticks, lice, and Lyme disease spirochetes (Borrelia burgdorferi sensu lato) in California state parks

Rio Grande wild turkeys (Meleagris gallopavo intermedia) were evaluated as potential hosts of ixodid ticks, lice, and Lyme disease spirochetes (Borrelia burgdorferi sensu lato [s.l.]) in three state parks in Sonoma County, California, USA, during 2003 and 2004. In total, 113 birds were collected, 50 (44.2%) of which were found to be infested by 361 ixodid ticks representing three species: the western black-legged tick (Ixodes pacificus, n=248), the rabbit tick (Haemaphysalis leporispalustris, n=112), and one American dog tick (Dermacentor variabilis). Year-round the prevalence of all ticks combined was unrelated to the age or sex of turkeys, and the prevalence of infestation by I. pacificus (35.4%) was significantly higher than it was for either H. leporispalustris (14.2%) or D. variabilis (0.9%). The proportion of the two prevalent tick species differed significantly by life stage with 86.3% of the I. pacificus and 82.1% of the H. leporispalustris enumerated being nymphs and larvae, respectively. Three species of lice were collected, including the chicken body louse Menacanthus stramineus (12.5% of total), Chelopistes meleagridis (37.5% of total), and Oxylipeurus polytrapezius (50% of total). The records for all three ticks are the first ever from wild turkeys, and those for the lice are the first from this host in the far-western United States. Wild turkeys potentially were exposed to the feeding activities of I. pacificus nymphs infected with B. burgdorferi s.l. as 15% of host-seeking nymphs (n=200) collected in woodlands used by turkeys as roosting or foraging areas were infected mainly with B. burgdorferi sensu stricto (s.s.). However, only one (1%) of 90 turkey blood specimens tested by PCR contained B. burgdorferi s.s., and four in vitro, complement-protein assays demonstrated that domestic turkey serum is moderately bacteriolytic for this spirochete. Taken together, these findings indicate that wild turkeys are important avian hosts of I. pacificus nymphs, but they appear to be inconsequential hosts of B. burgdorferi s.l.     

Evaluating the effects of historic bottleneck events: an assessment of microsatellite variability in the endangered,North Atlantic right whale

Commercial exploitation reduced the North Atlantic right whale (Eubalaena glacialis) population from c. 12,000 in the 11th century to around 300 by the 21st century. We examine the effect of this population decline on levels of genetic variation at 16 microsatellite loci and contrast levels of variability to that in a closely related species (E. australis). Of the 13 loci developed from the E. glacialis genome, 100% were polymorphic in E. australis. In contrast, nine loci were polymorphic in E. glacialis and four were fixed. Both allelic diversity (A) and heterozygosity (H) were significantly lower in E. glacialis than E. australis (A = 3.2 +/- 2.6 vs. A= 6.9 +/- 3.3, P < 0.001; H= 0.31 +/- 0.25 vs. H= 0.72 +/- 0.23, P < 0.001, respectively). Bottleneck anlayses indicate that the population is in mutation-drift equilibrium and that a genetic bottleneck did not occur during the most recent decline (18th-20th centuries). Nevertheless, low frequency alleles are relatively uncommon in E. glacialis, suggesting that genetic variability has been reduced in this population. Possible origins of low genetic variability are discussed, including the slow but continual erosion of alleles during the 800-year period of decline.     

Tick infestations of the eastern cottontail rabbit (Sylvilagus floridanus) and small rodentia in northwest Alabama and implications for disease transmission.

Studies were conducted over a four-county area of northwest Alabama to determine the association of eastern cottontail rabbits with Dermacentor variabilis, the eastern United States vector of Rocky Mountain spotted fever. A secondary objective was to compare infestations of this tick on rabbits with infestations on commonly encountered rodent species as a means of determining the relative importance of each in the disease transmission cycle. These epidemiologic surveys were conducted in response to reported fatal cases of Rocky Mountain Spotted Fever in two counties of the study area. From 202 eastern cottontail rabbits, 3,956 ticks were collected. Of this total, 79.87% were Haemphysalis leporispalustris, 9.15% Amblyomma americanum, 8.22% Ixodes dentatus, and 2.76% D. variabilis. Only immature stages of D. variabilis were collected from cottontail rabbits. Ticks were collected on rabbits in all months except November, and only one specimen was taken in January. Based on the average number of ticks per host collected in each month, April was the peak month for D. variabilis and I. dentatus. High values for H. leporispalustris also occurred at this time, but even higher values occurred in October and December. The heaviest infestation of A. americanum occurred during the month ofAugust and coincides with the activity period for the larvae of this species. Two hundred sixty-nine of the smaller Rodentia, comprising 13 species, yielded 264 ticks, all D. variabilis, and all but two were immature stages. Five rodent species, Microtus ochragaster Orozomys palustris, Peromyscus gossypinus, Peromyscus leucopus, and Sigmodon hispidus accounted for 95.83% of the ticks collected, and appeared to be preferred hosts for D. variabilis; all five had higher infestation levels per host than did the eastern cottontail rabbit. Data on host relationships in association with seasonal activity are presented.     

Feline cuterebrosis caused by a lagomorph-infesting Cuterebra spp. larva

Native species of rodents and lagomorphs in the Americas are the typical hosts of Cuterebra spp. larvae. Although these bot flies are relatively host specific, they occasionally parasitize other native and introduced mammals (including domestic animals and humans), an affliction termed cuterebrosis. Cuterebra spp. larvae generally cause benign, subcutaneous lesions (warbles), but when infesting domestic cats, they can invade the eyes, respiratory tract, and cerebral tissues, causing severe, and in some cases fatal, injury. Despite more than 2 dozen published reports of feline cuterebrosis, the type (rodent- or lagomorph-infesting) or species parasitizing domestic cats has rarely been determined. Here, I identify a larva removed from a kitten in southern Wisconsin as belonging to a lagomorph-infesting Cuterebra species, most likely C. abdominalis, based especially on features of the cuticular platelets covering its exterior, and its geographic location. This seems to be only the third substantiated report of feline cuterebrosis in more than 50 yr in which a larva has been identified beyond "Cuterebra spp." In each case, lagomorph-infesting species were involved, suggesting that domestic cats may not be susceptible to rodent-infesting Cuterebra species. However, because these studies are limited in number and geographic area, additional research is required to establish the spectrum of Cuterebra species involved in feline cuterebrosis.     

Induction of egg maturation and oviposition in the tick Ornithodoros parkeri (Acari: Argasidae)

Hemocoelic injection and vaginal insertion of selected male reproductive and non-reproductive tissue homogenates into fed-virgin female Ornithodoros parkeri stimulated varying degrees of ovum maturation and/or oviposition during 14 and 30 day observation periods, respectively. Mean times for oviposition and mean numbers of eggs laid per ovipositing female receiving hemocoelic injections of male reproductive tissue homogenates did not differ significantly from fed-mated controls. In addition, hemocoelic injection of male salivary glandular homogenate induced oviposition, yet synganglial homogenate did not. Although vaginal insertion induced both ovum maturation and oviposition, the effect was not as pronounced as when similar doses were administered by hemocoelic injection. These results indicate that a complex interrelated series of precopulatory and copulatory stimuli are necessary for oviposition to occur in fed O. parkeri.     

New records of soft ticks (Acari: Argasidae) in the Caatinga biome of Brazil,with a phylogenetic analysis of argasids using the nuclear Histone 3 (H3) gene

In Brazil, 19 species of the genus Ornithodoros (Acari: Argasidae) have been reported. The medical and veterinary importance of Ornithodoros ticks has increased substantially in recent decades, with the discovery of various relapsing fever Borrelia infecting Ornithodoros ticks. Herein, argasid ticks were collected during 2019–2020 from caves, abandoned nests and homes in various regions of Ceará State, Brazilian semiarid—Caatinga biome. In total, 289 ticks were collected and identified into five species: Ornithodoros cavernicolous (176 specimens), Ornithodoros fonsecai (81), Ornithodoros mimon (12), Ornithodoros rietcorreai (4), and a fifth species provisionally retained as Ornithodoros sp. Ubajara. Tick identifications were corroborated by a phylogenetic analysis inferred using the 16S rRNA gene. To extend the molecular characterization, DNA samples were tested by an additional PCR assay targeting the nuclear Histone 3 (H3) gene. Because there were no H3 sequences of argasids in GenBank, we extended this PCR assay for additional Ornithodoros species, available in our laboratory. In total, 15 partial sequences of the H3 gene were generated for 10 Ornithodoros species, showing 0% intraspecific polymorphism, and 1.5–11.6% interspecific polymorphism. Phylogenetic analyses inferred segregated Ornithodoros sp. Ubajara as a potential novel species. Our results also highlight the potential of the H3 gene for deeper phylogenetic analyses of argasids. The present study provides new data for argasid ticks of the genus Ornithodoros in the Caatinga biome. Because some of these tick species are human-biting ticks, active surveillance for the incidence of human infection due to Ornithodoros-borne agents is imperative in the Caatinga biome.

     

Avian and mammalian hosts for spirochete-infected ticks and insects in a Lyme disease focus in Connecticut.

Spirochetes and their vectors and reservoirs were studied in a Lyme disease focus in East Haddam, Connecticut, from mid-May through September 1983. Ixodes dammini subadults were comparable in number on white-footed mice (Peromyscus leucopus) (means = 2.9 +/- 3.6 SD) to those on 27 different species of birds (means = 2.3 +/- 4.2 SD) representing 11 families within the order Passeriformes. Less commonly found ticks on birds (means less than or equal to 0.1) were immature Ixodes dentatus and Haemaphysalis leporispalustris. Although spirochete-infected I. dammini larvae and nymphs were taken off eight and nine different species of birds, respectively, significantly fewer positive larvae were removed from birds than from white-footed mice. Spirochetes were detected in the midguts of I. dammini, Dermacentor variabilis, and H. leporispalustris and two species of insects (Cuterebra fontinella and Orchopeas leucopus). Possibly, arthropods other than I. dammini vector these spirochetes in northeastern United States. Spirochetes grew in a cell-free medium inoculated with bloods from four white-footed mice, one woodland jumping mouse (Napaeozapus insignis), one northern mockingbird (Mimus polyglottos), one gray catbird (Dumetella carolinensis), two prairie warblers (Dendroica discolor), one orchard oriole (Icterus spurius), one common yellowthroat (Geothlypis trichas), and one American robin (Turdus migratorius). We suggest that avian hosts, like mammals, develop spirochetemias of the causative agent of Lyme disease. Erythematous tissues from a white-footed mouse were infected with spirochetes.     

Nosema parkeri sp. n., a microsporidan from the argasid tick, Ornithodoros parkeri Cooley.

Nosema parkeri sp. n. is described from nymphs and adults of the argasid tick, Ornithodoros parkeri Cooley, from a laboratory colony. Schizogonic and sporogonic stages are described from various tick tissues. Spores are binucleate, measuring 3.2 (3-4) x 1.9 (1.8-2.5) micronm. Transmission is transovarial and transstadial. The parasite does not appear to affect adversely the development or reproduction of the tick. Dermacentor andersoni Stiles was experimentally infected. Attempts to infect Swiss mice by tick feeding or by injection of infected tick suspensions were unsuccessful. The microsporidan differs in structure from Encephalitozoon ixodis Weiser) and Nosema slovaca Weiser & Rehácek, the only other microsporidans known from ticks.     

Effects of temperature and tick weight on expression of autogeny in the argasid tick Ornithodoros parkeri Cooley (acari: Argasidae)

The effects of different temperatures on the expression of autogenic development in unfed/mated Ornithodoros parkeri Cooley females were examined. High temperature (29 C) induced autogeny in lower, middle and higher weight classes (11-20, 21-30, 31-40 mg, respectively) with all females in the highest weight class and most in the middle weight class ovipositing within 51 days post-mate. At a lower temperature (21 C) autogenic development was not expressed by higher and middle weight females, whereas lower weight females exhibited similar degrees of autogeny at both temperatures. Results are discussed in relation to presumptive factors involved in the control and mediation of autogeny.     

Nosema parkeri sp. n., a Microsporidan from the Argasid Tick, Ornithodoros parkeri Cooley

SYNOPSIS. Nosema parkeri sp. n. is described from nymphs and adults of the argasid tick, Ornithodoros parkeri Cooley, from a laboratory colony. Schizogonic and sporogonic stages are described from various tick tissues. Spores are binucleate, measuring 3.2 (3–4) × 1.9 (1.8–2.5) μm. Transmission is transovarial and transstadial. The parasite does not appear to affect adversely the development or reproduction of the tick. Dermacentor andersoni Stiles was experimentally infected. Attempts to infect Swiss mice by tick feeding or by injection of infected tick suspensions were unsuccessful. The microsporidan differs in structure from Encephalitozoon ixodis Weiser) and Nosema slovaca Weiser & Reháček, the only other microsporidans known from ticks.     

On the associations between Haplosyllis (Polychaeta, Syllidae) and gorgonians (Cnidaria, Octocorallaria), with the description of a new species

The present paper includes a morphological, ecological and biological updating of the three gorgonian associated species of Haplosyllis (Polychaeta, Syllidae) known to date: H. chamaeleon (symbiont with Paramuricea clavata in the Mediterranean), H. anthogorgicola (symbiont with Anthogorgia bocki in the Japanese seas) and H. villogorgicola , a new species living symbiotically with Villogorgia bebrycoides which is only known from Tenerife (Canary Islands, Eastern Central Atlantic). The new species is described on the basis of ecological, morphological, morphometric and statistical analysis of relevant characteristics. Each host colony harboured about 15 pale-yellowish worms, whose cryptic colouration mimicked that of the host. They occurred either on the host branches or partly hidden inside cavities formed by the fusion of two branches. The new species is characterized by the presence of simple chaetae with clearly bidentate tips all along the body, the presence of gland pore aggregates distributed in two lateral rows and two ventral patches on each palp and the absence of ciliary tufts on the pharyngeal papillae. H. villogorgicola sp. nov. is closely related to H. chamaeleon . Thus, it is compared with two populations of this species collected in the north-west and south-west Mediterranean. Stolons of H. chamaeleon are re-described as tetracerous and a peculiar posterior end regeneration process occurring in adult worms during the stolon formation is described. H. anthogorgicola is also re-described, with particular emphasis on its appendage and chaetal arrangements. The main features of the three associations are discussed in light of the current knowledge on symbiotic polychaetes, particularly cnidarian-associated syllids.  © 2002 The Linnean Society of London, Biological Journal of the Linnean Society , 2002, 77 , 455–477.     

First and southernmost records of Hirsutella (Ascomycota: Hypocreales) and Pandora (Zygomycota: Entomophthorales) species infecting Dermaptera and Psocodea

We present the first and southernmost records of the fungi Hirsutella strigosa Petch, H. citriformis Speare (Ascomycota: Hypocreales), and Pandora nouryi (Remaudière & Hennebert) Humber (Zygomycota: Entomophthorales) infecting Doru lineare (Eschscholtz) (Dermaptera: Forficulidae), Ectopsocus californicus (Banks) (Psocodea: Ectopsocidae), and Heterocaecilius sp. (Psocodea: Pseudocaeciliidae), respectively. This is the first report of naturally occurring pathogenic fungi infecting Psocoptera, and it is also the first report of P. nouryi from any host outside of the Aphididae. The three fungal species were morphologically described from their host insects and from microscopic preparations. Attempts to obtain pure fungal isolates were unsuccessful but slides and photographs of these fungi were preserved and deposited in mycological collections as herbarium material.     

ANALYSIS OF MITOCHONDRIAL DNA DIVERSITY WITHIN AND BETWEEN NORTH AND SOUTH ATLANTIC RIGHT WHALES

DNA sequences of the mitochondrial control region of 180 North Atlantic right whales ( Euhalaena glacialis ) and 16 South Atlantic right whales ( E. australis ) have been determined using a combination of direct DNA sequencing and single stranded conformation polymorphism (SSCP) analysis. Five haplotypes were found in E. glacialis , and 10 in E. australis , but none were shared, supporting the reproductive isolation and separate species status of the North and South Atlantic right whales. One haplotype in E, glacialis was found in only three males born before 1982 and this matriline will likely be lost soon. The nucleotide diversity estimates for the five North Atlantic right whale haplotypes was 0.6% and 2.0% for the 10 haplotypes found in the South Atlantic right whales. The average haplotypic diversity was 0.87 in E. glacialis and 0.96 in E. australis , which is consistent with other studies showing a lower level of genetic variation in the North Atlantic right whale. Phylogenetic analysis identified two major assemblages of haplotypes in E. australis from the samples collected from Peninsula Valdes, suggesting a mixing of two historically divergent populations. Using genetic distance measurements with a divergence rate of 0.5%–1.0%/myr, we estimate E. glacialis diverged from E. australis 3–12.5 mya.