''Ixodes angustus'' is a species of

parasitic Parasitism is a close relationship between species, where one organism, the parasite, lives on or inside another organism, the host, causing it some harm, and is adapted structurally to this way of life. The entomologist E. O. Wilson ha ...

tick Ticks (order Ixodida) are parasitic arachnids that are part of the mite superorder Parasitiformes. Adult ticks are approximately 3 to 5 mm in length depending on age, sex, species, and "fullness". Ticks are external parasites, living by ...

, whose range encompasses the majority of

Canada Canada is a country in North America. Its ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, covering over , making it the world's second-largest country by tota ...

Lindquist, Evert E., King Wan Wu, and B. Flahey. A handbook to the ticks of Canada (Ixodida: Ixodidae, Argasidae). Ottawa: Biological Survey of Canada, 2016. and the

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 U.S. state, states, a Washington, D.C., federal district, five ma ...

,Doss, Mildred A. Ticks and Tickborne Diseases: Geographical distribution of ticks. No. 3. US Government Printing Office, 1974.Keirans, James E., and Taina R. Litwak. "Pictorial key to the adults of hard ticks, family Ixodidae (Ixodida: Ixodoidea), east of the Mississippi River." Journal of Medical Entomology 26.5 (1989): 435-448. along with parts of northern

Mexico Mexico ( Spanish: México), officially the United Mexican States, is a country in the southern portion of North America. It is bordered to the north by the United States; to the south and west by the Pacific Ocean; to the southeast by Guate ...

.Guzmán-Cornejo, Carmen, and Richard G. Robbins. The genus Ixodes (Acari: Ixodidae) in Mexico: adult identification keys, diagnoses, hosts, and distribution. ARMED FORCES PEST MANAGEMENT BOARD WASHINGTON DC, 2010. ''I. angustus'' is a member of the

Ixodidae The Ixodidae are the family of hard ticks or scale ticks, one of the three families of ticks, consisting of over 700 species. They are known as 'hard ticks' because they have a scutum or hard shield, which the other major family of ticks, the 'so ...

(hard-bodied) family of ticks. It is most abundant in cool, moist biomes such as

riparian A riparian zone or riparian area is the interface between land and a river or stream. Riparian is also the proper nomenclature for one of the terrestrial biomes of the Earth. Plant habitats and communities along the river margins and banks a ...

boreal Boreal may refer to: Climatology and geography *Boreal (age), the first climatic phase of the Blytt-Sernander sequence of northern Europe, during the Holocene epoch *Boreal climate, a climate characterized by long winters and short, cool to mild ...

montane Montane ecosystems are found on the slopes of mountains. The alpine climate in these regions strongly affects the ecosystem because temperatures fall as elevation increases, causing the ecosystem to stratify. This stratification is a crucial ...

zones. ''I. angustus'' is a host generalist and has been discovered feeding on more than 90 different host species, including humans and domestic dogs.Stephenson, Nicole, Johnny Wong, and Janet Foley. "Host, habitat and climate preferences of Ixodes angustus (Acari: Ixodidae) and infection with Borrelia burgdorferi and Anaplasma phagocytophilum in California, USA." Experimental and Applied Acarology 70.2 (2016): 239-252. ''I. angustus'' has been identified as a potential vector for

Lyme disease Lyme disease, also known as Lyme borreliosis, is a vector-borne disease caused by the '' Borrelia'' bacterium, which is spread by ticks in the genus '' Ixodes''. The most common sign of infection is an expanding red rash, known as erythema ...

Peavey, C. A., R. S. Lane, and T. Damrow. "Vector competence of Ixodes angustus (Acari: Ixodidae) for Borrelia burgdorferi sensu stricto." Experimental & applied acarology 24.1 (2000): 77-84. but is not considered a principle vector due to the relative rarity with which it feeds on humans.

Description

Adult females are approximately 2 mm unfed and can grow up to 7 mm when engorged with a blood meal. They possess a diamond shaped non-ornate dorsal plate (otherwise known as a shield) with rounded edges.

Palps Pedipalps (commonly shortened to palps or palpi) are the second pair of appendages of chelicerates The subphylum Chelicerata (from New Latin, , ) constitutes one of the major subdivisions of the phylum Arthropoda. It contains the sea spiders, ...

are long, with a half-diamond shape (straight outer edge and a rounded inner edge). Adult males grow to around 2 mm, and cannot become engorged with blood as their inflexible back plate extends to cover the entire dorsal side of the tick.

are much smaller, thicker, and more ovular than females.

Life-cycle

''Ixodes angustus'' has a multi-stage life-cycle consisting of egg, larva, nymph and adult stage. They can complete this life-cycle in 7 months under mild temperatures, a shorter period than most other

Ixodes ''Ixodes'' is a genus of hard-bodied ticks (family Ixodidae). It includes important disease vectors of animals and humans ( tick-borne disease), and some species (notably '' Ixodes holocyclus'') inject toxins that can cause paralysis. So ...

.Hadwen, Seymour. "The life history of Ixodes angustus (Banks)." Journal of the Entomological Society of British Columbia 1 (1911): 37-38. ''Ixodes angustus'' larvae hatch after approximately 73 days and acquire blood meals from a vertebrate, most often a small mammal like a squirrel or

mouse A mouse ( : mice) is a small rodent. Characteristically, mice are known to have a pointed snout, small rounded ears, a body-length scaly tail, and a high breeding rate. The best known mouse species is the common house mouse (''Mus musculus' ...

. These meals take place over an ~3 day feeding period, the protein from which enables the larvae to moult into a nymph after an average of 60 days. Nymphs again feed for approximately 3 days on vertebrates before becoming adults after an average of 30 days. Adult females will feed for ~7 days on a vertebrate host before laying egg clusters over a 16-day period. Adult males are only rarely found on hosts and are thus assumed to wait for potential mates in or around the nest of their prior host.

Distribution

''Ixodes angustus'' has a wide distribution in North America and has been recorded in all Canadian provinces except

Saskatchewan Saskatchewan ( ; ) is a province in western Canada, bordered on the west by Alberta, on the north by the Northwest Territories, on the east by Manitoba, to the northeast by Nunavut, and on the south by the U.S. states of Montana and North ...

(although it is suspected to occur there), the majority of continental US states, and the Mexican state of

Coahuila Coahuila (), formally Coahuila de Zaragoza (), officially the Free and Sovereign State of Coahuila de Zaragoza ( es, Estado Libre y Soberano de Coahuila de Zaragoza), is one of the 32 states of Mexico. Coahuila borders the Mexican states of N ...

. There have been several erroneous records of I. angustus in

South South is one of the cardinal directions or compass points. The direction is the opposite of north and is perpendicular to both east and west. Etymology The word ''south'' comes from Old English ''sūþ'', from earlier Proto-Germanic ''*sunþa ...

and

Central America Central America ( es, América Central or ) is a subregion of the Americas. Its boundaries are defined as bordering the United States to the north, Colombia to the south, the Caribbean Sea to the east, and the Pacific Ocean to the west. ...

, but thus far there are no ''Bona fide''

neotropical The Neotropical realm is one of the eight biogeographic realms constituting Earth's land surface. Physically, it includes the tropical terrestrial ecoregions of the Americas and the entire South American temperate zone. Definition In bi ...

records of ''I.angustus''.Guglielmone, Alberto A., et al. "The hard ticks of the world." New York: Springuer (2014). Within this extensive range, ''I. angustus'' is most prevalent in cool, damp habitats such as boreal, montane and riparian zones.

Potential as a disease vector

Despite a wide range and demonstrated potential to carry ''

Borrelia burgdorferi ''Borrelia burgdorferi'' is a bacterial species of the spirochete class in the genus '' Borrelia'', and is one of the causative agents of Lyme disease in humans. Along with a few similar genospecies, some of which also cause Lyme disease, it ...

'', the causative agent of Lyme disease, ''I. angustus'' is considered a bridge vector of lesser importance due to its nidicolous behaviour. Important ''Ixodes'' bridge vectors such as '' I. scapularis'' and '' I. pacificus'' exhibit a questing behaviour where they actively hunt for new hosts, enabling them to frequently acquire human or domestic animal hosts. In contrast, ''I. angustus'' rarely leaves the nest of its host, thus almost exclusively feeding on small or medium-sized nesting mammals like mice and squirrels. This behaviour also limits the accessibility of ''I. angustus'' to scientific study, as it is often missed by sampling techniques which rely upon ticks actively seeking a host such as

tick dragging Tick dragging is a method for collecting ticks used by parasitologists and other researchers studying tick populations in the wild. Method To conduct a tick drag, a researcher uses a strip of white cloth, usually corduroy, mounted on a pole th ...

or trapping.

References

{{Taxonbar, from=Q10538562 angustus Animals described in 1899 Arachnids of North America