Haemaphysalis leporispalustris

Packard, 1869

rabbit tick, grouse tick

Haemaphysalis leporispalustris, commonly known as the rabbit , is a hard tick ( ) with one of the widest distributions of any New World tick , ranging from Alaska to Argentina. It is a three- tick specialized on lagomorph hosts (rabbits and hares), with also frequently found on ground-dwelling birds. Despite rarely feeding on humans, it serves as a for several affecting wildlife and domestic animals, including rickettsii, Coxiella burnetii, and Francisella tularensis. A newly recognized human pathogen, Rickettsia lanei, has been associated with this tick species.

Haemaphysalis leporispalustris by CBG Photography Group, Centre for Biodiversity Genomics. Used under a CC0 license.

Ixodiphagus texanus from description by Leland Ossian Howard, 1907, plate with details by Robert Evans Snodgrass (1875-1962). Used under a Public domain license.

Pronunciation

How to pronounce Haemaphysalis leporispalustris: //hɛ.mə.fɪˈseɪ.lɪs ˌlɛ.pɔr.ɪs.pəˈlʌs.trɪs//

These audio files are automatically generated. While they are not always 100% accurate, they are a good starting point.

Identification

Distinguished from other Haemaphysalis by the rectangular (not hexagonal) basis of the and that are wider than long. The unornamented separates it from ornamented . Extremely similar to other members; molecular identification may be necessary for definitive determination. Resembles Dermacentor (wood ) in general appearance but lacks the scutum patterns common in that genus.

Images

Appearance

measure approximately 1 mm in length. The body lacks . are wider than long. The is unornamented in both sexes. The basis of the is rectangular rather than hexagonal. (wrinkles) are present at the base of the body. The capitulum projects forward prominently from the body. Overall appearance resembles the "wood " (Dermacentor ).

Habitat

Occurs in diverse environments across its broad range, from northern forests to tropical regions. climb vegetation to quest for , preferring curved vegetation 12–15 cm in height with smaller diameter tips. and are found on host animals, particularly on ears, between ears, or on necks of lagomorphs. Development rates are temperature-dependent, proceeding faster at higher temperatures.

Distribution

Widely distributed in the Americas from Alaska through Canada, the United States, Mexico, and Central America to Argentina. Documented in Venezuela, Bolivia, Brazil, Colombia, Rica, Guatemala, Panama, Paraguay, and Peru. Present in Atlantic rain forest environments in Brazil (Rio de Janeiro and Minas Gerais states). One of the largest distributions for a originating in the New World.

Seasonality

peaks during summer and declines during winter. In temperate regions, the can extend to a year, especially in cold climates. Activity patterns vary by and temperature conditions.

Diet

Obligate blood-feeding . Feeds on rabbits (Sylvilagus spp.), hares (Lepus spp.), and occasionally ground-feeding birds. Rarely feeds on humans. Takes blood meals during each active (, , ).

Host Associations

Sylvilagus spp. (cottontail rabbits) - primary Common ; frequently found on ears, between ears, or on neck
Lepus spp. (hares/jackrabbits) - primary Includes snowshoe hares; common
Ground-dwelling birds - (larval stage) frequently found on ground-feeding birds; includes Arremon semitorquatus, Corythopis delalandi, Fluvicola nengeta, Troglodytes musculus, Volatinia jacarina, Turdus rufiventris in Brazil
Humans - rare incidental Rarely feeds on humans

Life Cycle

Three- with hemimetabolic development. Stages: , , , . Each active stage feeds on a host, drops to ground, molts, then seeks next host. Host switching may occur between stages, especially if host is not a lagomorph. Complete cycle may take up to one year in cold climates; faster at higher temperatures. of some documented.

Behavior

Highly -specific in host-seeking . Climbs vegetation to quest for hosts, positioning on curved vegetation 12–15 cm high—matching typical rabbit height. Uses carbon dioxide sensing and body temperature to locate hosts. Exhibits negative (upward movement on vegetation). Upon host contact, either accepts and feeds or rejects and drops to ground to repeat . Prefers dry surfaces and darker environments. Becomes still and extends when waiting for host stimuli.

Ecological Role

for multiple bacterial including rickettsii ( agent), Coxiella burnetii (Q fever), Francisella tularensis (), and Rickettsia lanei (newly described human pathogen). maintains R. rickettsii in . Serves as a maintenance for zoonotic agents in wild lagomorph populations. Heavy can cause macrocytic normochromic anemia or death in small mammals.

Human Relevance

Rarely bites humans, so direct medical importance is limited. However, recently identified as the for lanei, a newly recognized human causing spotted fever illness in California. Important veterinary concern for rabbits, hares, and small mammals—heavy cause anemia and mortality. Control in domestic rabbits uses ivermectin; pyrethrin, permethrin, and amitraz are toxic to small mammals and must be avoided.

Similar Taxa

Haemaphysalis longicornis (Asian longhorned tick)Similar ; distinguished by parthenogenetic in H. longicornis and subtle morphological differences. H. longicornis is an in the U.S. not to the Americas.
Dermacentor variabilis (American dog tick)Resembled in general "wood " appearance; distinguished by rectangular basis and lack of patterns in H. leporispalustris.
Other Haemaphysalis speciesExtremely similar ; often require molecular identification or examination of shape and palpal proportions for separation.

More Details

Thermal biology

Critical temperature varies with developmental stage and nutritional state in and . Engorged nymphs have low critical temperature (36–40°C) one day after drop-off, increasing to 46–47°C over 15 days, then decreasing post-. Unfed females maintain 42–43°C for two months, with further decrease during engorgement. rates correlate with these thermal changes.

Pathogen associations

Documented to carry rickettsii, Coxiella burnetii, Francisella tularensis, Anaplasma bovis, and Rickettsia lanei. Maintains R. rickettsii in the Americas through , serving as a despite rarely biting humans.

Taxonomic note

First described by Packard in 1869. Molecular identification via 16S rRNA and 12S rRNA sequencing may be necessary for definitive identification due to morphological similarity with .