| Ixodiphagus hookeri | |
|---|---|
 | |
| adult hatched from an nymph of Ixodes ricinus | |
Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Arthropoda |
| Class: | Insecta |
| Order: | Hymenoptera |
| Family: | Encyrtidae |
| Genus: | Ixodiphagus |
| Species: | I. hookeri |
| Binomial name | |
| Ixodiphagus hookeri (Howard, 1908) | |
| Synonyms [1] | |
| |
Ixodiphagus hookeri, the tick wasp, is an encyrtid wasp which lays its eggs into ticks. [3] It seems to use a symbiotic bacteria, Wolbachia pipientis , to weaken the tick's immune system.
Ixodiphagus hookeri is a small wasp which has the typical morphology of an encyrtid wasp and is blackish in colour, it measures 0.8-0.9mm in length and has a wing length span of 1.5mm. Its head is dorsally flattened with very large compound eyes. In females, the antennae have eleven segments and the antennae are club shaped; while in males they have ten segments and are thread-like. [4]
Ixodiphagus hookeri has a short flight period in the summer in Europe. The female normally oviposits an egg into the body of an unfed nymph of Ixodes ricinus , but has been recorded ovipositing in the adults of Rhipicephalus sanguineus . The egg remains in diapause until the nymph engorges on vertebrate blood, at which point the egg becomes active. Some eggs are not successful, as the tick's immune system can encapsulate the egg, which results in the egg becoming melanised and dying. The bacteria Wolbachia is symbiotic with the wasp, and its presence in ticks is a possible indicator of infestation by tick wasps; Wolbachia may have a role in suppressing the host's immune system response to the wasp. The wasp larvae then exist as koinobiont parasitoids in the tick for 28 to 70 days before emerging.
Ticks from the genera Ornithodoros , Amblyomma , Dermacentor , Haemaphysalis , Hyalomma , Ixodes and Rhipicephalus are recorded as having been infected by I. hookeri. In Europe, Ixodes ricinus appears to be the preferred species and the marsh tick Dermacentor reticulatus is not used as a host. Because of the potential importance of I. hookeri as a natural enemy of ticks, it has been extensively researched. [5] Different populations of I. hookeri around the world show different host preferences, complicating attempts to use this species as a biological control for ticks. [3] [6]
I. hookeri occurs worldwide, except in Antarctica.
Ticks 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 feeding on the blood of mammals, birds, and sometimes reptiles and amphibians. The timing of the origin of ticks is uncertain, though the oldest known tick fossils are from the Cretaceous period, around 100 million years old. Ticks are widely distributed around the world, especially in warm, humid climates.
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 'soft ticks' (Argasidae), lack. They are ectoparasites of a wide range of host species, and some are vectors of pathogens that can cause human disease.
Chalcid wasps are insects within the superfamily Chalcidoidea, part of the order Hymenoptera. The superfamily contains some 22,500 known species, and an estimated total diversity of more than 500,000 species, meaning the vast majority have yet to be discovered and described. The name "chalcid" is often confused with the name "chalcidid", though the latter refers strictly to one constituent family, the Chalcididae, rather than the superfamily as a whole; accordingly, most recent publications (e.g.,) use the name "chalcidoid" when referring to members of the superfamily.
Trichogramma is a genus of minute polyphagous wasps that are endoparasitoids of insect eggs. Trichogramma is one of around 80 genera from the family Trichogrammatidae, with over 200 species worldwide.
Dermacentor variabilis, also known as the American dog tick or wood tick, is a species of tick that is known to carry bacteria responsible for several diseases in humans, including Rocky Mountain spotted fever and tularemia. It is one of the best-known hard ticks. Diseases are spread when it sucks blood from the host. It may take several days for the host to experience symptoms.
Parasitoid wasps are a large group of hymenopteran superfamilies, with all but the wood wasps (Orussoidea) being in the wasp-waisted Apocrita. As parasitoids, they lay their eggs on or in the bodies of other arthropods, sooner or later causing the death of these hosts. Different species specialise in hosts from different insect orders, most often Lepidoptera, though some select beetles, flies, or bugs; the spider wasps (Pompilidae) exclusively attack spiders.
"Candidatus Midichloria" is a candidatus genus of Gram-negative, non-endospore-forming bacteria, with a bacillus shape around 0.45 µm in diameter and 1.2 µm in length. First described in 2004 with the temporary name IricES1, "Candidatus Midichloria" species are symbionts of several species of hard ticks. They live in the cells of the ovary of the females of this tick species. These bacteria have been observed in the mitochondria of the host cells, a trait that has never been described in any other symbiont of animals.
Ixodes scapularis is commonly known as the deer tick or black-legged tick, and in some parts of the US as the bear tick. It was also named Ixodes dammini until it was shown to be the same species in 1993. It is a hard-bodied tick found in the eastern and northern Midwest of the United States as well as in southeastern Canada. It is a vector for several diseases of animals, including humans and is known as the deer tick owing to its habit of parasitizing the white-tailed deer. It is also known to parasitize mice, lizards, migratory birds, etc. especially while the tick is in the larval or nymphal stage.
Ixodes ricinus, the castor bean tick, is a chiefly European species of hard-bodied tick. It may reach a length of 11 mm (0.43 in) when engorged with a blood meal, and can transmit both bacterial and viral pathogens such as the causative agents of Lyme disease and tick-borne encephalitis.
Nasonia vitripennis is one of four known species under the genus Nasonia - small parasitoid wasps that afflict the larvae of parasitic carrion flies such as blowflies and flesh flies, which themselves are parasitic toward nestling birds. It is the best known and most widely studied of the parasitoid wasps, and their study forms a vital part of the information used to describe the order Hymenoptera, along with information from bees and ants. This parasitoid behaviour makes the wasps an interest for the development of biopesticide and biological systems for controlling unwanted insects.
Rhipicephalus sanguineus, commonly called the brown dog tick, kennel tick, or pantropical dog tick, is a species of tick found worldwide, but more commonly in warmer climates. This species is unusual among ticks in that its entire lifecycle can be completed indoors. The brown dog tick is easily recognized by its reddish-brown color, elongated body shape, and hexagonal basis capituli. Adults are 2.28 to 3.18 mm in length and 1.11 to 1.68 mm in width. They do not have ornamentation on their backs.
Ixodes pacificus, the western black-legged tick, is a species of parasitic tick found on the western coast of North America. I. pacificus is a member of the family Ixodidae. It is the principal vector of Lyme disease in that region. I. pacificus typically feeds on lizards and small mammals therefore its rate of transmission of Lyme disease to humans is around 1% of adults. It is an ectoparasite that attaches itself to the outside of its host and feeds on the host's blood. It can have a heteroxenous lifestyle or monoxenous life cycle depending on how many hosts it feeds on in each cycle. I. pacificus has a four stage life cycle that takes around 3 years to complete. These stages include egg, larva, nymph, and adult. They prefer dense woodland habitats or areas of brush and tall grass.
Haller's organ is a complex sensory organ possessed by hard and soft ticks. Not found outside of Acari, it is proposed to function like the chemosensation of insect antennae, but is structurally different. Ticks, being obligate parasites, must find a host in order to survive. Bloodmeals are necessary for completion of the life cycle, including reproduction and ontogenetic development. First described in 1881, it was named for its discoverer, Haller. While Haller initially proposed it was involved in auditory sensation, this was rejected in favor of olfactory sensation by 1905. This theory was supported by Lee's behavioral studies as early as 1948.
Ticks of domestic animals directly cause poor health and loss of production to their hosts. Ticks also transmit numerous kinds of viruses, bacteria, and protozoa between domestic animals. These microbes cause diseases which can be severely debilitating or fatal to domestic animals, and may also affect humans. Ticks are especially important to domestic animals in tropical and subtropical countries, where the warm climate enables many species to flourish. Also, the large populations of wild animals in warm countries provide a reservoir of ticks and infective microbes that spread to domestic animals. Farmers of livestock animals use many methods to control ticks, and related treatments are used to reduce infestation of companion animals.
Arsenophonus nasoniae is a species of bacterium which was previously isolated from Nasonia vitripennis, a species of parasitoid wasp. These wasps are generalists which afflict the larvae of parasitic carrion flies such as blowflies, houseflies and flesh flies. A. nasoniae belongs to the phylum Pseudomonadota and family Morganellaceae. The genus Arsenophonus, has a close relationship to the Proteus (bacterium) rather than to that of Salmonella and Escherichia. The genus is composed of gammaproteobacterial, secondary-endosymbionts which are gram-negative. Cells are non-flagellated, non-motile, non-spore forming and form long to highly filamentous rods. Cellular division is exhibited through septation. The name 'Arsenophonus nasoniae gen. nov., sp. nov.' was therefore proposed for the discovered bacterium due to its characteristics and its microbial interaction with N. vitripennis. The type strain of A. nasoniae is Strain SKI4.
Paul Schulze was "the most important German tick taxonomist of the early 20th century." Between 1929 and 1937, he described 19 genera, 17 subgenera, 150 species and 150 subspecies of ixodid ticks. He was essentially an amateur taxonomist, working alone for most of his career, not consulting the major tick collections or collaborating with other tick taxonomists.
"Candidatus Cardinium" is a genus of Gram-negative parasitic bacteria that reside within cells of some arthropods and nematodes. Although they have not yet been isolated in pure culture, they are known to negatively influence reproduction in their hosts in order to further their own proliferation. This leads to their classification as a reproductive parasite. One of the only other examples of this type of parasitism is the genus Wolbachia, which also infects arthropods. These two genera can also co-infect the same animal, as in some nematodes. "Candidatus Cardinium" bacteria use many of the same methods to interfere with host reproduction as Wolbachia, including inducing cytoplasmic incompatibility and distorting the sex ratio in the host population to favor females. The mechanisms by which "Candidatus Cardinium" induces these conditions in hosts are thought to be different from the mechanisms used by Wolbachia. "Candidatus Cardinium" bacteria are maternally inherited; infections are maintained through generations through the egg cells. It is estimated that 6–10% of all arthropods are infected with "Candidatus Cardinium" bacteria.
Natalia Aleksandrovna Filippova was a world authority on the taxonomy of mites and especially ticks. Her monographs on the identification, morphology, development, distribution and behaviour of the family Argasidae and the sub-families of Ixodinae and Amblyomminae are standard works on these important vectors of disease.
Neoehrlichia mikurensis (NM), previously known as Candidatus Neoehrlichia mikurensis, is an intracellular, gram-negative bacteria belonging to the family Anaplasmataceae. Using ticks as vectors, it spreads between animals - mainly rodents, but other mammals as well as humans can get infected. After Borrelia and Rickettsia, it is believed to be the third most common tick-borne pathogen able to infect humans. Between 2009 and 2019, 45 human cases of NM-infections were found in Sweden.