The ticks (Acari: Ixodida: Argasidae, Ixodidae) of Paraguay.

The ticks reported in Paraguay, which are here reviewed, can be categorized as 'endemic or established' (Argas persicus or a sibling species, Ornithodoros hasei, O. rostratus, O. rudis, O. talaje/O. puertoricensis, Amblyomma aureolatum, Am. auricularium, Am. brasiliense, Am. cajennense, Am. calcaratum, Am. coelebs, Am. dissimile, Am. dubitatum, Am. incisum, Am. longirostre, Am. nodosum, Am. ovale, Am. pacae, Am. parvum, Am. pseudoconcolor, Am. rotundatum, Am. scutatum, Am. tigrinum, Am. triste, Dermacentor nitens, Haemaphysalis juxtakochi, H. leporispalustris, Ixodes loricatus, Rhipicephalus microplus, and Rh. sanguineus), 'probably endemic or established' (Ar. miniatus, Ar. monachus, Am. argentinae, Am. humerale, Am. naponense, Am. oblongoguttatum, Am. pseudoparvum, I. aragaoi/I. pararicinus, I. auritulus, I. luciae), or 'erroneously reported from Paraguay' (O. coriaceus, Am. americanum and Am. maculatum). Most Paraguayan tick collections have been made in the Chaco phyto-geographical domain, in the central part of the country. Argas persicus or a related species, Am. cajennense, D. nitens, Rh. microplus and Rh. sanguineus are important parasites of domestic animals. Ornithodoros rudis, Am. aureolatum, Am. brasiliense, Am. cajennense, Am. coelebs, Am. incisum, Am. ovale and Am. tigrinum have all been collected from humans. In terms of public health, the collections of Am. cajennense and Am. triste from humans may be particularly significant, as these species are potential vectors of Rickettsia rickettsii and Ri. parkeri, respectively.

Anointing chemicals and ectoparasites: effects of benzoquinones from millipedes on the lone star tick, Amblyomma americanum.

Many mammals and birds roll on or rub themselves with millipedes that discharge benzoquinones. Chemicals transferred from millipedes onto the integument of anointing animals are thought to deter ectoparasites. We tested the lone star tick, Amblyomma americanum (L.), for responses to three widespread components of millipede defensive secretions, 1,4-benzoquinone; 2-methyl-1,4-benzoquinone (toluquinone); and 2-methoxy-3-methyl-1,4-benzoquinone (MMB). In toxicity tests, ticks were confined for 1 hr in filter-paper packets treated with serial dilutions of each of the benzoquinones or the commercial acaricide permethrin. Ticks were least affected by toluquinone, and most affected by permethrin. Of the benzoquinones, only MMB showed repellent activity. Behavioral assays were more sensitive than mortality for measuring the effects of the benzoquinones. Latencies for ticks to right themselves and to climb were greater with all compounds, even at the lowest concentrations, than with controls. Ticks exposed to low concentrations of benzoquinones appeared to recover over time, whereas those exposed to high concentrations exhibited behavioral abnormalities 1-3 mo later. Our results indicate that benzoquinones appropriated via anointing may reduce the tick loads of free-ranging animals, although key questions remain on the amounts of these compounds available to and effectively appropriated by anointing animals.

Las garrapatas (acari ixodida) de la región zoogeográfica neotropical

Listado de las especies de garrapatas de la región neotropical, que también presenta la distribución y los hospedadores preferenciales, las referencias para los estados posembrionarios, y los estadios aún sin escribir. También discute las enfermedades de los hombres y los animales derivadas de la infestación por garrapatas

Las garrapatas (acari ixodida) de la región zoogeográfica neotropical

Listado de las especies de garrapatas de la región neotropical, que también presenta la distribución y los hospedadores preferenciales, las referencias para los estados posembrionarios, y los estadios aún sin escribir. También discute las enfermedades de los hombres y los animales derivadas de la infestación por garrapatas

Ticks from a Morelet's crocodile in Belize.

Parasitism of crocodilians by ticks has rarely been reported, and to our knowledge only seven published accounts exist. On 3 July 1999, we collected four ticks from a subadult Morelet's crocodile (Crocodylus moreletii) captured in northern Belize. These were identified as Amblyomma dissimile (one female), and Amblyomma sp. (two nymphs, one larva). The crocodile was captured on land approximately 100 m from water, and all four ticks were attached to loose skin on the lateral surface of the tail. Crocodilians are most susceptible to terrestrial ectoparasites, including ticks, during overland movements. However, most such movements occur in response to drought, when tick questing activity is suppressed, which likely accounts for the small numbers of tick specimens recorded from crocodilians and the absence of any noticeable impact of parasitism on host fitness.

A world checklist of genera, subgenera, and species of ticks (Acari: Ixodida) published from 1973-1997.

Researchers on ticks and tickborne diseases have been extremely fortunate in having at their fingertips the tick bibliographies produced by Harry Hoogstraal and his coworkers at the U.S. Naval facility at Cairo, Egypt, and by Mildred Doss and her colleagues at the U.S. Department of Agriculture laboratory at Beltsville, Maryland, USA. The Doss checklist of tick families, genera, species, and subspecies is now 25 years out of date, and the following checklist of one new genus, nine new subgenera, and 110 new species of Ixodida brings together the nomenclature on ticks produced during the last quarter century.

First records of Hyalomma aegyptium (Acari: Ixodida: Ixodidae) from the Russian spur-thighed tortoise, Testudo graeca nikolskii, with an analysis of tick population dynamics.

During the fall of 1995 and the spring of 1996, 77 statistically comparable tick collections, comprising 792 specimens, were made from adults of the Russian spur-thighed tortoise, Testudo graeca nikolskii, at 4 sites along Russia's Black Sea coast. These are the first tick collections reported from T. g. nikolskii since its recognition as a taxonomic entity. All ticks were determined to be Hyalomma (Hyalomma) aegyptium, a common tortoise parasite in southern Russia that in 1930 was erroneously designated the type of subgenus Hyalommasta. Male ticks were recovered from more tortoises (67) than were females (57) or immatures (14), and nymphs were seen only in the fall. Significantly more ticks parasitized male tortoises than females, perhaps because males of T. g. nikolskii have larger home ranges. However, no functional relationship was found between tortoise ventral surface area and degree of tick infestation. Like other tortoise ticks, H. aegyptium is expected to decline in concert with its increasingly threatened hosts.

Deer ticks (Ixodes scapularis) and the agents of Lyme disease and human granulocytic ehrlichiosis in a New York City park.

Rodent trapping and drag sampling in Van Cortlandt Park, New York City, yielded all stages of Ixodes scapularis, the deer tick vector of Lyme disease and human granulocytic ehrlichiosis (HGE). Polymerase chain reaction analyses of the ticks showed Borrelia burgdorferi and the Ehrlichia sp. that causes HGE.

Does Aponomma varanensis (Acari: Ixodida: Ixodidae) occur on the Taiwanese mainland?

On 15 July 1976, teams from the U.S. Naval Medical Research Unit No. 2, Taipei, Taiwan, made 3 collections of ticks from beneath the dorsal scales of the Taiwan stink snake, Elaphe carinata, at Makung in the Penghu Islands, which lie astride the Tropic of Cancer in the Taiwan Strait between southern mainland China and Taiwan proper. These ticks were later determined to be Aponomma varanensis (Supino, 1897), but this discovery was never published, and no member of the genus Aponomma has heretofore been reported from Taiwan or any of its outlying islets. Because suitable hosts, including E. carinata, are abundant on Taiwan and because A. varanensis is widely distributed in tropical Asia, it is argued that this or a related species of Aponomma will one day be found on the Taiwanese mainland.

Fellow eyes in aphakic and pseudophakic bullous keratopathy.

We studied the contralateral eye of ten consecutive patients in whom corneal decompensation had occurred following cataract extraction to detect the beginnings of any corneal disease in that eye. Patients with a previous history of surgery, trauma, or ocular disease were excluded. In the study group, the mean endothelial cell count was 1,852 cells/mm2 and the central corneal thickness was 0.572 mm. A comparable group of control eyes with cataracts demonstrated a mean endothelial cell count of 2,446 cells/mm2 and central pachymetry of 0.514 mm. Patients with corneal edema following cataract extraction should be carefully evaluated for the presence of endothelial dysfunction in the opposite eye.

Ornithodoros (Alectorobius) puertoricensis (Acari: Argasidae): redescription by scanning electron microscopy.

The female, male, nymphal instars, and larva of Ornithodoros puertoricensis Fox are redescribed from specimens collected in Haiti. Data on host species and geographic distribution are also presented.

True prophylactic gentamicin application in experimental Pseudomonas keratitis.

In an experimental model of Pseudomonas keratitis, 50 rabbit eyes were treated with gentamicin sulfate (3 mg/mL) prophylactically on four different treatment regimens. One group (13 eyes) received one drop of gentamicin sulfate every hour to a total of four drops, the last drop 25 minutes before inoculation. A second group (13 eyes) was given one drop of gentamicin sulfate one hour before inoculation. A third group (12 eyes) received one drop of gentamicin sulfate per minute to a total of 4 drops, the last drop 25 minutes prior to inoculation. A fourth group (12 eyes) received one drop of antibiotic 25 minutes before inoculation. Twelve control eyes received saline solution. Subsequently, a superficial corneal scratch was inflicted and each eye received one drop (0.05 mL) of a solution containing Pseudomonas aeruginosa. The infection rate in all four experimental groups was low, whereas all control eyes became infected. These results demonstrate the effectiveness of prophylactic antibiotic application in the prevention of Pseudomonas keratitis prior to superficial ocular trauma.

Intraocular pressure by noncontact tonometry with and without soft contact lenses.

We compared the intraocular pressure of 43 eyes (23 patients) with and without soft contact lenses. Two measurements were taken on each eye while the patients were wearing their soft contact lenses, and then immediately after the lenses were removed. Intraocular pressure measurements were taken by noncontact tonometry. The results showed that the power of the contact lens was a significant predictor of the change in intraocular pressure. In addition, when the 43 eyes were broken down into two groups, those with hyperopic lenses and those with myopic lenses, the difference in intraocular pressure was significantly larger for the group with hyperopic lenses than for the group with myopic lenses.