Argas persicus infests chickens mostly in the eastern U. This one host tick is found throughout North America. It is widely distributed throughout California, but populations are concentrated around the central coastal and sierra foothill areas.
It primarily feeds on horses and deer from fall through early spring. Heavy infestations of horses may cause emaciation and anemia 1. After hatching from the egg, larvae attach to a host, feed and detach, remaining on the animal. Subsequently, they molt to the nymphal stage, resume feeding and detach again. After they develop into adults and feed once again, they drop to the ground and lay their eggs, where the cycle begins once again.
The Pacific Coast Tick is a three host tick which commonly feeds on rodents, especially squirrels, as subadults, and on cattle, horses, deer, and humans as adults. This is one of the most widely distributed ticks in California. It is found throughout the state except for the very dry regions of the central valley and the southeastern desert region.
The only other areas it has been collected in are Oregon and Baja, Mexico 1. This tick is well known as a vector of the Rocky Mountain spotted fever rickettsia in the northwestern U. It is also commonly responsible for tick paralysis in humans, livestock, and wild mammals 1. However, in California, this tick poses little threat to human and animal health because of its scanty distribution in less populated areas of the state.
It has been collected primarily in the upper eastern part of the state, from Modoc county down to the eastern range of the northern Sierras. Dermacentor variabilis. It is the most important vector of the Rocky Mountain spotted fever rickettsia in the eastern U.
It has also been found responsible for tick paralysis in some states. This tick is widespread throughout the U. In California, it is most frequently found along the coastal ranges down the length of the state, but has also been collected in the central valley and along the eastern Sierra range 1.
Ixodes pacificus. The Western black-legged tick is a three host tick that primarily feeds on lizards and small rodents during its subadult life stages, and large mammals, commonly deer, canids, horses, and humans, as adults.
It is the putative vector of the Lyme disease spirochete and the equine granulocytic ehrlichiosis rickettsia in California. This tick is found in the western U. Discourage ticks around your home by keeping lawns mowed, cutting back dense vegetation, and removing debris piles.
If you are experiencing an issue with ticks on your property, call Advanced IPM at Quality, environmentally conscious service at a reasonable cost. Are you looking for a quote or to schedule an appointment? Commercial Residential. Company Name. California Nevada. The number of confirmed cases reported to state health authorities ranged from 57 to 97 per year between and Typical of all disease surveillance systems, the number of Lyme disease cases may be under-reported or misclassified i.
Assuming these conditions apply across the United States, it is clear that the incidence of Lyme disease in California is much less than it is in highly endemic areas of the northeastern and upper midwestern United States. Overall, the incidence of Lyme disease in California is usually only 0. Nonetheless, certain California counties pose a much higher risk of contracting Lyme disease than others. For example, the highest average incidence from to occurred in the northwestern counties of Trinity 4.
These county estimates vary slightly due to year-to-year variation in reporting, but the patterns of risk remain similar. There are two major families of ticks: the slow-feeding hard ticks Ixodidae and the rapid-feeding soft ticks Argasidae. These have significantly different life histories. Globally, four species of hard ticks in the genus Ixodes serve as primary vectors of Borrelia burgdorferi or closely related spirochetes to people.
All hard ticks have four life stages: the egg, and three parasitic stages that suck the blood of vertebrates, including two immature stages larva and nymph and the adult stage. After an immature or adult female feeds, protein digested from the blood meal is used by larvae or nymphs to complete metamorphosis to the next stage larva to nymph, nymph to adult or by female ticks to produce hundreds or thousands of eggs.
Ixodes pacificus , like all hard ticks, possesses plate-like body armor. Larvae and nymphs feed on birds, small mammals, and especially lizards, for up to several days, whereas the adult females feed on medium- or large-sized mammals for about a week. Female ticks develop and eventually deposit —1, eggs in soil or litter areas.
The life cycle takes three years to complete, from the egg stage to egg-laying females, in the Hopland area of northwestern California, but it may take less or more time than that throughout the broad geographical distribution of this tick in far-western North America. It has eight legs, a dark brownish-black plate on its back, and a light-colored, translucent abdomen.
Attached nymphs are especially prone to be overlooked because of their small size and somewhat reduced feeding time compared with adult female ticks. While feeding, adult females increase their initial body weights fold or more. Males attach to people infrequently compared to adult females, imbibe small quantities of blood, and therefore hardly increase in size.
Adult ticks also have eight legs, whereas the pinhead-sized larvae have only six legs and do not commonly attach to people. The western blacklegged tick is the most widely distributed and abundant of the 48 tick species in California. Five additional species of Ixodes ticks have been found infected naturally with Lyme disease-group spirochetes in the state, but all of them infrequently or never attach to people.
Nymphs of the western blacklegged tick may be encountered in a variety of habitats, but they are most accessible and plentiful in certain types of dense woodlands or forests such as those harboring oak, Pacific madrone, or Douglas fir trees.
The nymphs abound in hardwood forests or woodlands carpeted with leaf litter or fir needles, but they are much less abundant and accessible in more open habitats such as grassland. Unlike adult ticks, the nymphs usually do not ascend grasses or shrubs while host-seeking. Instead, they seek their hosts within or atop litter on the forest floor, or on branches, logs, and the basal portions of tree trunks up to a height of 3 to 4 feet. Any activity that places people in direct contact with shed leaves, fir needles, or wood e.
Nymphs have a decided host preference for lizards. In the laboratory, when nymphs were offered a choice of different hosts, they preferred western fence lizards versus a bird or two species of rodents.
After feeding fully, nymphs drop off the host and molt to the adult stage weeks to months later. Adult female and male ticks climb low-lying vegetation in grassland, woodland-grass, or brush, where they lie in wait for hours or days for potential hosts, including medium- to large-sized mammals, such as black bears, coyotes, deer, foxes or jack rabbits, to brush against them.
Once adult ticks contact a suitable host, female ticks begin to search for a suitable attachment site. In contrast, male western blacklegged ticks mainly seek vertebrate hosts to locate receptive females for mating purposes. Ixodes pacificus adults are commonly encountered by humans in open grassland or chaparral brushlands , along the margins of trails especially the uphill vegetative borders of hillside hiking trails in parklands and wildlands, in semirural communities, and in some suburban areas that support populations of deer and other wildlife, particularly in coastal counties and the foothills of the Sierra Nevada Mountain range.
They also are common in areas where two habitat or vegetational types merge e. The California Department of Public Health maintains an interactive Web site displaying locations where some public health agencies have collected adult or nymphal western blacklegged ticks and tested them for the agent that causes Lyme disease.
In northwestern California, Ixodes pacificus nymphs can be found from January through October in different localities, though they are most active from March to July and usually reach peak abundance in mid- to late spring. However, people are most likely to be bitten in spring and early summer when the nymphs are abundant in forests carpeted with leaf or fir-needle litter. In central and southern California, nymphs are difficult to collect in woodlands during the daytime, so their seasonal activity period has not been well-defined except for a few sites in Los Angeles and Santa Barbara counties.
Host-seeking activity by nymphs there was truncated and spanned February to early May or early June. Adult ticks generally seek their hosts from late fall through spring but are most active during winter in the north coast Mendocino County and Sierra Nevada foothills Yuba County. In central and southern California, adult ticks quest from late November until late April or early May.
On clear, warm days, people are more apt to be exposed to adult ticks in early morning or late afternoon because adult tick activity is highest when relative humidity is high and temperatures are cool. Lyme disease cases in California residents having no travel history and exhibiting the expanding rash associated with early-stage Borrelia burgdorferi infection called erythema migrans peak from May to July following the maximum abundance of Ixodes pacificus nymphs April to June.
Even in heavily populated metropolitan areas, such as Alameda County in the San Francisco Bay region where the Lyme disease incidence is quite low, isolated woodland pockets exist where the hazard of confronting spirochete-infected nymphs is elevated. This rash, which may not be apparent on dark-skinned people, usually begins at the location where the tick attached and expands slowly to several inches in diameter before disappearing within 3 to 4 weeks.
Antibiotic treatment reduces the duration of the rash to about a week. Many patients experience fatigue, headache, fever, chills, and other flulike symptoms during the initial stage of illness. Without treatment, other signs or symptoms may occur days to months later. These can involve the skin multiple secondary rashes , musculoskeletal system migratory pain in joints, tendons, muscles, or bones , neurologic system severe headache, facial palsy, memory loss , and enlarged lymph nodes.
More rarely, inflammation of the heart or eyes, or liver damage, may ensue, too. People with untreated late-stage Lyme disease may begin to experience signs or symptoms months or years after infection, which may result in arthritic, neurologic, or further skin manifestations.
Deaths attributable to Lyme disease are rare events: sudden cardiac deaths linked to Lyme carditis inflammation of the heart were reported during a 9-month period in for three young adults who resided in the northeastern United States. Dogs are susceptible to Lyme disease and may develop arthritis or lameness, lethargy, loss of appetite, enlarged lymph nodes, or other clinical conditions. Consult a veterinarian if you suspect your dog has Lyme disease.
Cats, horses, and livestock also may become infected but rarely develop clinical signs. Preventing exposure to ticks is the best way to reduce the risk of getting Lyme disease. Know how to recognize the western blacklegged tick and the areas and times of year where and when this tick occurs.
Always inspect clothing, exposed skin, and pets for ticks when outdoors in tick habitats, and oneself for several days afterward to ensure that one or more nymphs may not have been overlooked.
If you spend time outdoors in tick-infested areas, you can significantly reduce the risk of exposure to Ixodes pacificus and other human-biting ticks by taking a few simple precautions.
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