RESUMO
Host-parasite dynamics can play a fundamental role in both the establishment success of invasive species and their impact on native wildlife. The net impact of parasites depends on their capacity to switch effectively between native and invasive hosts. Here we explore host-switching, spatial patterns and simple fitness measures in a slow-expanding invasion: the invasion of Asian house geckos (Hemidactylus frenatus) from urban areas into bushland in Northeast Australia. In bushland close to urban edges, H. frenatus co-occurs with, and at many sites now greatly out-numbers, native geckos. We measured prevalence and intensity of Geckobia mites (introduced with H. frenatus), and Waddycephalus (a native pentastome). We recorded a new invasive mite species, and several new host associations for native mites and geckos, but we found no evidence of mite transmission between native and invasive geckos. In contrast, native Waddycephalus nymphs were commonly present in H. frenatus, demonstrating this parasite's capacity to utilize H. frenatus as a novel host. Prevalence of mites on H. frenatus decreased with distance from the urban edge, suggesting parasite release towards the invasion front; however, we found no evidence that mites affect H. frenatus body condition or lifespan. Waddycephalus was present at low prevalence in bushland sites and, although its presence did not affect host body condition, our data suggest that it may reduce host survival. The high relative density of H. frenatus at our sites, and their capacity to harbour Waddycephalus, suggests that there may be impacts on native geckos and snakes through parasite spillback.
Assuntos
Interações Hospedeiro-Parasita , Lagartos/fisiologia , Lagartos/parasitologia , Infestações por Ácaros/veterinária , Animais , Austrália , Espécies Introduzidas , Infestações por Ácaros/transmissão , ÁcarosRESUMO
Ixodes anatis Chilton is of veterinary and conservation importance in New Zealand due to its association with the threatened kiwi (Aves: Apterygidae: Apteryx spp.). Since the tick's description in 1904, there has been debate regarding its correct taxonomic position and nomenclature. Herein all life stages of this species are redescribed and accompanied by electron micrographs and drawings. The systematics, host preferences, distribution, disease relationships and conservation biology of the species are also discussed.
Assuntos
Patos/parasitologia , Ixodes/anatomia & histologia , Ixodes/fisiologia , Características de História de Vida , Paleógnatas/parasitologia , Animais , Feminino , Ixodes/classificação , Ixodes/crescimento & desenvolvimento , Larva/anatomia & histologia , Larva/classificação , Larva/crescimento & desenvolvimento , Larva/fisiologia , Masculino , Microscopia Eletrônica de Varredura , Nova Zelândia , Ninfa/anatomia & histologia , Ninfa/classificação , Ninfa/crescimento & desenvolvimento , Ninfa/fisiologiaRESUMO
A new subgenus, Australixodes n. subgen., is described for the kiwi tick, Ixodes anatis Chilton, 1904. The subgenus Coxixodes Schulze, 1941 is validated for the platypus tick, Ixodes (Coxixodes) ornithorhynchi Lucas, 1846, sister group of the subgenus Endopalpiger Schulze, 1935. A phylogeny from mitochondrial genomes of 16 of the 22 subgenera of Ixodes (32 spp.) indicates, for the first time, the relationships of the subgenera of Ixodes Latreille, 1795, the largest genus of ticks.
Assuntos
Genoma Mitocondrial , Ixodes , Ixodidae , Animais , Ixodes/genética , Ixodidae/genética , FilogeniaRESUMO
BACKGROUND: Numerous laboratory and fewer field-based studies have found that ixodid ticks develop more quickly and survive better at temperatures between 18 °C and 26 °C and relative humidity (RH) between 75 and 94%. Ixodes anatis Chilton, 1904, is an endophilic, nidicolous species endemic to North Island brown kiwi (Apteryx mantelli) (NIBK) and the tokoeka (Apteryx australis), and little is known about the environmental conditions required for its development. The aims of this study were to determine and compare the conditions of temperature and RH that ensure the best survival of the kiwi tick and the shortest interstadial periods, in laboratory conditions and outdoors inside artificial kiwi burrows. METHODS: Free-walking engorged ticks were collected off wild kiwi hosts and placed in the laboratory under various fixed temperature and humidity regimes. In addition, sets of the collected ticks at different developmental stages were placed in artificial kiwi burrows. In both settings, we recorded the times taken for the ticks to moult to the next stage. RESULTS: Larvae and nymphs both showed optimum development at between 10 °C and 20 °C, which is lower than the optimum temperature for development in many other species of ixodid ticks. However, larvae moulted quicker and survived better when saturation deficits were < 1-2 mmHg (RH > 94%); in comparison, the optimum saturation deficits for nymph development were 1-10 mmHg. CONCLUSIONS: Our results suggest that the kiwi tick has adapted to the stable, but relatively cool and humid conditions in kiwi burrows, reflecting the evolutionary consequences of its association with the kiwi.
Assuntos
Ixodes , Paleógnatas/parasitologia , Animais , Temperatura Baixa , Interações Hospedeiro-Parasita , Umidade , Ixodes/crescimento & desenvolvimento , Ixodes/fisiologia , Laboratórios , Estágios do Ciclo de Vida , Muda , Nova Zelândia , Ninfa/crescimento & desenvolvimento , Ninfa/fisiologia , Estações do Ano , TemperaturaRESUMO
Established populations of Asian longhorned ticks (ALT), Haemaphysalis longicornis, were first identified in the United States (US) in 2017 by sequencing the mitochondrial cytochrome c oxidase subunit I (cox1) 'barcoding' locus followed by morphological confirmation. Subsequent investigations detected ALT infestations in 12, mostly eastern, US states. To gain information on the origin and spread of US ALT, we (1) sequenced cox1 from ALT populations across 9 US states and (2) obtained cox1 sequences from potential source populations [China, Japan and Republic of Korea (ROK) as well as Australia, New Zealand and the Kingdom of Tonga (KOT)] both by sequencing and by downloading publicly available sequences in NCBI GenBank. Additionally, we conducted epidemiological investigations of properties near its initial detection locale in Hunterdon County, NJ, as well as a broader risk analysis for importation of ectoparasites into the area. In eastern Asian populations (China/Japan/ROK), we detected 35 cox1 haplotypes that neatly clustered into two clades with known bisexual versus parthenogenetic phenotypes. In Australia/New Zealand/KOT, we detected 10 cox1 haplotypes all falling within the parthenogenetic cluster. In the United States, we detected three differentially distributed cox1 haplotypes from the parthenogenetic cluster, supporting phenotypic evidence that US ALT are parthenogenetic. While none of the source populations examined had all three US cox1 haplotypes, a phylogeographic network analysis supports a northeast Asian source for the US populations. Within the United States, epidemiological investigations indicate ALT can be moved long distances by human transport of animals, such as horses and dogs, with smaller scale movements on wildlife. These results have relevant implications for efforts aimed at minimizing the spread of ALT in the United States and preventing additional exotic tick introductions.
Assuntos
Distribuição Animal , Ixodidae/fisiologia , Animais , DNA Mitocondrial/genética , Complexo IV da Cadeia de Transporte de Elétrons/genética , Regulação Enzimológica da Expressão Gênica , Estados UnidosRESUMO
PURPOSE: The Manx shearwater flea Ceratophyllus (Emmareus) fionnus Usher, 1968 is a host-specific parasitic insect apparently restricted to the Isle of Rùm, off the west coast of Scotland. Although C. (E.) fionnus is one of only a small number of insect species endemic to the British Isles, its conservation status has never been evaluated. To enable effective management, the conservation status of the species was assessed. METHODS: The conservation status of C. (E.) fionnus was evaluated using host and distribution records in conjunction with two assessment rubrics; the IUCN Red List Categories and Criteria: Version 3.1, and a flea-specific assessment rubric developed previously. RESULTS: Ceratophyllus (Emmareus) fionnus was found to be threatened with extinction due to its hyperendemicity on the Isle of Rùm and was classified as vulnerable. CONCLUSION: Based on the findings of the assessment, immediate conservation action to protect C. (E.) fionnus is encouraged and a recovery plan is outlined. This includes surveys and studies of the bionomics of the species in conjunction with in-situ management of the known population. The creation of insurance populations through conservation translocations is also encouraged.
Assuntos
Aves/parasitologia , Conservação dos Recursos Naturais , Espécies em Perigo de Extinção , Sifonápteros , Animais , EscóciaRESUMO
Due to a processing error, the presentation of Table 1 was incorrect. The corrected table is given below. The original article has been corrected.
RESUMO
The longhorned tick, Haemaphysalis longicornis, feeds upon a wide range of bird and mammalian hosts. Mammalian hosts include cattle, deer, sheep, goats, humans, and horses. This tick is known to transmit a number of pathogens causing tick-borne diseases, and was the vector of a recent serious outbreak of oriental theileriosis in New Zealand. A New Zealand-USA consortium was established to sequence, assemble, and annotate the genome of this tick, using ticks obtained from New Zealand's North Island. In New Zealand, the tick is considered exclusively parthenogenetic and this trait was deemed useful for genome assembly. Very high molecular weight genomic DNA was sequenced on the Illumina HiSeq4000 and the long-read Pac Bio Sequel platforms. Twenty-eight SMRT cells produced a total of 21.3 million reads which were assembled with Canu on a reserved supercomputer node with access to 12 TB of RAM, running continuously for over 24 days. The final assembly dataset consisted of 34,211 contigs with an average contig length of 215,205 bp. The quality of the annotated genome was assessed by BUSCO analysis, an approach that provides quantitative measures for the quality of an assembled genome. Over 95% of the BUSCO gene set was found in the assembled genome. Only 48 of the 1066 BUSCO genes were missing and only 9 were present in a fragmented condition. The raw sequencing reads and the assembled contigs/scaffolds are archived at the National Center for Biotechnology Information.
RESUMO
Several hundred strains of Bacillus thuringiensis (Bt), isolated in New Zealand from samples of soil and sheep fleece, were tested for toxicity to larvae of the blowfly Lucilia cuprina Wiedemann. Characterization of the Bt strains revealed that three of the more active strains produced Cry1Ba (an insecticidal protein present in Bt mother cell crystal inclusion) that was toxic to blowflies. These strains were evaluated for the ability to prevent experimentally induced fly strike in a bioassay by using first instars. Results with undiluted spore/crystal preparations were variable, but they generally prevented fly strike on sheep maintained on pasture for 3-6 wk. Spore viability was satisfactory throughout the trials and environmental factors (e.g., precipitation and UV radiation) seemed to have minimal effect on persistence. The loss of fly strike protection in these experiments correlated with the movement of spore/crystal toxicity away from the skin as a result of wool growth. Solubilized protein preparations were not as potent as spore/crystal preparations and fly strike protection lasted only from 1 to 3 wk. Vegetative forms of the Cry1Ba-producing strains of Bt did not establish on the fleece of sheep, did not produce significant sporulation, and no protection against fly strike was achieved. Escherichia coli expressing recombinant Cry1Ba protein was toxic to larvae in vitro but did not effectively protect sheep from fly strike because blowfly larvae were able to establish readily 8 d posttreatment. In a single field experiment involving 80 sheep per group, a spore/crystal preparation from a Bt strain expressing Cry1Ba provided less protection from naturally acquired fly strike than afforded by a commercially available dip.
Assuntos
Proteínas de Bactérias , Toxinas Bacterianas , Endotoxinas , Inseticidas , Miíase/veterinária , Proteínas Recombinantes , Doenças dos Ovinos/prevenção & controle , Animais , Bacillus thuringiensis/fisiologia , Toxinas de Bacillus thuringiensis , Proteínas de Bactérias/biossíntese , Proteínas de Bactérias/genética , Toxinas Bacterianas/biossíntese , Toxinas Bacterianas/genética , Dípteros/crescimento & desenvolvimento , Endotoxinas/biossíntese , Endotoxinas/genética , Proteínas Hemolisinas , Larva , Miíase/prevenção & controle , Controle Biológico de Vetores , Ovinos/microbiologia , Esporos Bacterianos/fisiologia , Lã/microbiologiaRESUMO
Humans coming into New Zealand occasionally, and unwittingly, bring exotic ticks with them, either attached to their bodies or with luggage. Of the 172 available records for tick interception at New Zealand's border, half can be attributed to human agency. Here, together with an outline of tick biology and ecology, we present evidence of at least 17 species of ticks being brought in by humans, with Australia, North America and Asia the most frequent countries of origin. Risks posed by some of the nine species of ticks already in New Zealand are briefly examined. Sites of attachment of ticks and associated symptoms where these have been recorded are presented. Diseases transmitted by ticks and most likely to be encountered by travellers are briefly discussed together with the most practical method of tick removal. A plea is made for practitioners to increase their awareness of the risks to New Zealand's biosecurity and public health posed by ticks and to ensure that as many as possible of these unwelcome 'souvenirs' are collected and passed on for identification.
Assuntos
Infestações por Carrapato/epidemiologia , Doenças Transmitidas por Carrapatos/epidemiologia , Carrapatos , Viagem , Animais , Humanos , Nova Zelândia/epidemiologia , Saúde Pública , Fatores de Risco , Infestações por Carrapato/prevenção & controle , Doenças Transmitidas por Carrapatos/prevenção & controleRESUMO
Duvaucel geckos (Hoplodactylus duvaucelii) are large endemic lizards that have been extirpated from the New Zealand mainland due to introduced mammalian predators. This species has subsequently become the subject of species translocation conservation management in an endeavour to increase the number of populations and as a part of island ecological restoration. Blood sampling of a captive adult male after tail autotomy led to the discovery of a Rickettsia-like organism within this gecko's erythrocytes. We conclude that this infection was acquired at the gecko's source location, a remote island closed to the general public and lacking potential invasive parasite reservoir reptiles. The likely vector is the native mite Geckobia naultina. This finding represents valuable new baseline information about the health parameters of this threatened species. Particularly in the light of the paucity of reported blood parasitism in New Zealand reptiles, the conservation management of this species through relocation and captive-breeding, and the on-going concerns regarding the introduction of novel parasites to New Zealand.
Assuntos
Lagartos , Infecções por Rickettsia/veterinária , Rickettsia/classificação , Rickettsia/isolamento & purificação , Animais , Espécies em Perigo de Extinção , Masculino , Infecções por Rickettsia/microbiologiaRESUMO
Reports of myiasis in humans in New Zealand are somewhat rare, and little attention has been paid to this issue in the local medical literature. A number of Diptera (fly) families present in New Zealand have been associated with cases of human myiasis: Calliphoridae (7 species), Fanniidae (2 species), Muscidae (3 species), Oestridae (4 species), Phoridae (3 species), Psychodidae (1 species), Sarcophagidae (2 species), Stratiomyidae (1 species) and Syrphidae (1 species). Despite these numbers, there have only been 6 published records and we obtained further 16 unpublished reports of myiasis acquired in New Zealand. Records of imported myiasis in humans are also rare, with only 2 published and 6 unpublished cases obtained. As many medical practitioners are unaware of myiasis or encounter it rarely, we provide a brief discussion of the clinical features and treatment.