Leather ticks
| Leather ticks | ||||||||||||
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Starved female argas reflexus (5 mm) |
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| Systematics | ||||||||||||
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| Scientific name | ||||||||||||
| Argasidae | ||||||||||||
| CL Koch , 1844 |
The leather ticks (Argasidae, from ancient Greek argas , poisonous animal), also seam ticks , are a family of ticks (Ixodida) within the mites (Acari). Around 190 species are known around the world, most of which are found in the tropics and subtropics .
features
The types of leather ticks reach body sizes of three to fourteen millimeters. In contrast to the shield ticks (Ixodidae), the leather ticks do not have a back shield . The head ( Gnathosoma ) is drawn in under the body and cannot be seen from above, the cuticle is leathery.
distribution
Leather ticks are ectoparasites and suck blood from vertebrates , especially birds and bats , but also many others, including snakes and lizards . When they are not sitting by their hosts , they are mainly found in crevices and the nesting material of their hosts that attack them at night. Most species live in the nests or burrows of their hosts (nidicol), species that do not live in nests are rarely infested. The exception is e.g. B. Argas transversus , which uses the Galápagos giant tortoises as host and completes their entire life cycle there without ever leaving the host. Leather ticks can wait for their hosts to return in the nests of migratory birds and can therefore get along without food for a long time. Ornithodoros papillipes holds the record with eleven years of survival without eating.
In their blood meals, the leather ticks use different individuals, which often belong to the same species. But there are also host-changing species, especially when several potential host species share a nest.
Life cycle
A larva (with three pairs of legs) hatches from the egg of the leather ticks, followed by several nymph stages (with four pairs of legs), the last of which sheds its skin to become an adult. All stages suckle blood, mostly on the same host species. As a rare exception, some stages of some species do not eat, for example the larvae of some Ornithodoros species or the adults of the genus Otobius . The immature stages usually only take food once before each moult, rarely twice, and then leave the host and crawl into a hiding place. Males and females ingest several blood meals during their life, after which the female can lay down a clutch of eggs (up to seven times). In contrast to the ticks, the blood meals last less long (30 minutes to a few hours; exception: genus Argas ).
The number of nymph stages is variable between the species, but sometimes also within the same species. Most species have three or four nymph stages, but there are from two to eight. Often the males need one molt less than the females to reach sexual maturity.
In the case of leather ticks, fertilization of the female takes place away from the host in the environment (usually in the host's burrow or nest). The animals find each other through signal substances ( pheromones ). These often have an effect on older nymphs. A substance that acts as a pheromone is the guanine contained in the feces .
Leather ticks as a disease carrier
As bloodsuckers, leather ticks can also transmit various diseases. The most important bird parasites include the Persian leather tick ( Argas persicus ), which transmits bird spirochetosis, and other species of the genus Argas , such as the pigeon tick . They can transmit ASF among pigs .
Ornithodorus moubata , which occurs in some areas of Africa and transmits tick relapse fever there, plays a particularly important role for humans . It lives in the network of grass huts and can multiply there en masse. In some areas, residents have made the habit of burning their homes at regular intervals to reduce tick infestation. Tick relapse fever is mostly transmitted in the Mediterranean region by Ornithodorus erraticus and in America by Ornithodorus turicata . Other species that appear significant as parasites of humans or livestock are Otobius megnini and Ornithodoros lahorensis .
Systematics
The number and delimitation of the genera within the leather ticks is very controversial between different scientists. " The tick taxonomy of the Argasidae is in turmoil, it resulted in competing genus classifications that differ enormously from one another ". The genus name is controversial for no fewer than 133 of the 193 recognized valid species. A generally recognized list of the genres is therefore impossible. The current reference list includes the following categories:
- Antricola : bat parasite
- Argas : especially bird and bat parasites, including the pigeon tick ( Argas reflexus ), 61 species
- Ornithodoros (sometimes written differently as Ornithodorus ): 112 species
- Nothoaspis : monotypical, the only species of Nothoaspis reddelli is a bat parasite
- Otobius : 2 species
The status and possibly the delimitation of the genus Carios is particularly controversial .
Fossil record
The oldest fossil evidence of a leather tick is a larva found in Cretaceous amber from New Jersey . The species is extremely similar to recent species.
literature
- Family Argasidae . In: HE Gruner, M. Moritz, W. Dunger (Hrsg.): Textbook of special zoology. Invertebrates , 4th part Arthropoda (without Insecta) . 4th edition, G. Fischer Verlag 1993, p. 361.
Individual evidence
- ↑ a b Alberto A. Guglielmone, Richard G. Robbins, Dmitry A. Apanaskevich, Trevor N. Petney, Agustin Estrada-Pena, Ivan G. Horak, Renfu Shao, Stephen C. Barker (2010): The Argasidae, Ixodidae and Nuttalliellidae (Acari: Ixodida) of the world: a list of valid species names. PDF
- ↑ a b James H. Oliver, Jr. (1989): Biology and Systematics of Ticks (Acari: Ixodida). Annual Review of Ecology and Systematics Vol. 20: 397-430.
- ↑ YS Balashov (1984): Interaction between blood-sucking arthropods and Their hosts, and its influence on vector potential. Annual Revue of Entomology 29: 137-156.
- ↑ James E. Keirans & Carleton M. Clifford (1975): Nothoaspis reddelli, New Genus and New Species (Ixodoidea: Argasidae), from a Bat Cave in Mexico. Annals of the Entomological Society of America, Volume 68, Number 1: 81-85.
- ↑ Hans Klompen & David Grimaldi (2001): First Mesozoic Record of a Parasitiform Mite: a Larval Argasid Tick in Cretaceous Amber (Acari: Ixodida: Argasidae). Annals of the Entomological Society of America Volume 94, Number 1: 10-15.
