an investigation into the emission sites of the volatile pheromone produced by females of argas (persicargas) leaving open in turn the genital orifice, coxal apertures and anus, the present study has shown that engorged female argas walkerae release at least 1 volatile pheromone mainly, or maybe exclusively, from the genital aperture. although this aggregation-inducing pheromone is perceived by all post-larval stages, engorged males of a. walkerae react most strongly. a possible, but only slight, emission through the anus and the coxal aperatures is also indicated. most probably, this airborne biosub ...19854011154
studies on the critical water mass, rehydration capability and potential, acute chill tolerance and supercooling point of argas (persicargas) walkerae (acari: argasidae).the critical water mass, defined as the water mass remaining in a dehydrated tick in the non-ambulatory state, differed only slightly between light and heavy mass groups of argas walkerae and averaged 23.6% and 23.2%, respectively, in males and 28.4% and 28.0%, respectively, in females. all ticks survived dehydration to 50%, 75% or 100% of their critical water mass, and 95% of them rehydrated during their subsequent incubation at 95% relative humidity (rh) and 28 degrees c for 14 days and regain ...200111403425
morphology and structural organization of gene's organ in argas walkerae.electron microscopy revealed that gene's organ in females of argas walkerae kaiser & hoogstraal (ixodida: argasidae) is formed as a double-sac structure consisting of an outer epithelial and an inner cuticular sac. the latter emerges through the camerostomal aperture to the exterior in ovipositing ticks. the epithelial sac forms the corpus and the two blind-ending horns, which pass into the epithelium of the excretory duct of a gland at each side of gene's organ and envelop the cuticular sac. bo ...200111776461
tick paralysis in australia caused by ixodes holocyclus neumann.ticks are obligate haematophagous ectoparasites of various animals, including humans, and are abundant in temperate and tropical zones around the world. they are the most important vectors for the pathogens causing disease in livestock and second only to mosquitoes as vectors of pathogens causing human disease. ticks are formidable arachnids, capable of not only transmitting the pathogens involved in some infectious diseases but also of inducing allergies and causing toxicoses and paralysis, wit ...201121396246
nyamanini and midway viruses define a novel taxon of rna viruses in the order, we report the sequencing and classification of nyamanini virus (nymv) and midway virus (midwv), two antigenically related viruses that were first isolated in 1957 and 1966, respectively. although these viruses have been cultured multiple times from cattle egrets, seabirds, and their ticks, efforts to classify them taxonomically using conventional serological and electron microscopic approaches have failed completely. we used a random shotgun sequencing strategy to define the genomes of nym ...200919279111
the prevalence and distribution of argas walkerae (acari: argasidae) in the eastern region of the eastern cape province, south africa.the prevalence and geographic distribution of the fowl tampan, argas walkerae kaiser & hoogstraal, 1969 was determined in the eastern region of the eastern cape province, south africa by inspecting two fowl houses in the vicinity of each of 72 randomly selected communal cattle dip-tanks. tampans were collected from 102 (70.8%) of the 144 fowl houses in the neighbourhood of 57 (79.2%) of the 72 selected dip-tanks, and the localities of the collections were mapped. argas walkerae was present in fo ...200818575068
investigations on the host seeking and finding of argas (persicargas) walkerae (ixodoidea: argasidae).in investigations concerning the influence of stimuli emitted by chickens on the host-finding behaviour of hungry female adult argas walkerae ticks, we found that 92.5% of the ticks migrated to the stimulus source following their simultaneous exposure to odours and to a co2 gradient increasing in the direction of the chicken, as opposed to 67.5% following their exposure to kairomones of chickens in the absence of co2. migration of the ticks toward the stimulus source was precipitated by a wide r ...19911792235
experimental studies on the replication and transmission of crimean-congo hemorrhagic fever virus in some african tick african tick species were studied as potential vectors of crimean-congo hemorrhagic fever (cchf) virus. engorged nymphae of 4 ixodid species, hyalomma marginatum rufipes, h. truncatum, rhipicephalus evertsi mimeticus, and amblyomma hebraeum, were inoculated intracoelomically with cchf virus and assayed for virus content at varying times post-inoculation. the virus replicated in all 4 species, reaching maximum titers of 4.6-5.5(10) fluorescence focus units per ml on days 5-9 post-inoculatio ...19892494900
are ticks venomous animals?as an ecological adaptation venoms have evolved independently in several species of metazoa. as haematophagous arthropods ticks are mainly considered as ectoparasites due to directly feeding on the skin of animal hosts. ticks are of major importance since they serve as vectors for several diseases affecting humans and livestock animals. ticks are rarely considered as venomous animals despite that tick saliva contains several protein families present in venomous taxa and that many ixodida genera ...201425006341
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