Hard Ticks - Overseas

Many of the hard tick species that infect animals in the UK are also present in other parts of Europe and the rest of the world information on these can be found here. There are many tick species that are important both in the effects of their ectoparasitism but also in their ability to transmit other infectious agents.

Rhipicephalus spp.

Rhipicephalus (Boophilus) microplus

Also known as:

Tropical cattle tick Southern cattle tick

This is considered the most serious external parasites of Australian cattle, though they also affect cattle accross the southern hemisphere and the southern states of the USA. It is able to complete its life cycle in just 2 months under optimal conditions and lay 2000 - 3000 eggs during this time. It is important in its ability to act as a vector for Babesia bigemina, Borrelia theileri in South America and in Australia of Coxialla burnetti and Anaplasma marginale. These organisms can be passed down for up to 5 generations of ticks regardless of the hosts on which they feed as they can be passed transovarially between generations.

• Warmer climates
• Causes paralysis in livestock
• Vectors for diseases such as
  • Theileria parva which causes East Coast Fever
  • Babesia bigemina which affects ruminants, mainly in Africa
  • Babesia canis and Ehrlichia canis which affects dogs in warmer climates worldwide

Boophilus spp.

These species are important due to their ability to transmit Babesia spp. and Anaplasma marginale in cattle. They exist in tropical and subtropical climates and so are predominately found in Asia, Africa, central America and northern Australia. There are several important veterinary species, all of which are one host ticks and are mainly important in cattle though they can be seen in most ungulates.

Boophilus annulatus

Also known as:

Blue cattle tick Texas cattle fever tick

The entire life cycle of this tick is spent on a single host and can be completed in just 6 weeks. It is an important species as it is a vector for Babesia bigemina and Babesia bovis that are responsible for texas cattle fever. As well as its ability to transmit Anaplasma marginale like many other tropical hard ticks.

Amblyomma spp.

These ticks can be identified by;

• Large size
• Ornate scutums
• Eyes present
• Festoons
• Long palps

These ticks are distributed throughout tropical and sub-tropical areas of Africa as well as in temperate North America. The large mouth parts cause large painful bites and allow the females to ingest large volumes of blood which can lead to anaemia.

Amblyomma americanum

Also known as:

Lone star tick

This tick is found throughout North America and is primarily important as a vector but has also been shown to reduce weight gain in cattle. It is responsible for transmission of Rickettsia rickettsii, Francisella tularensis, Q fever and Berrelia burgdorferi

• Warmer climates
• Transmits Cowdria ruminatium (heartwater) in Africa

Hyalomma spp.

• Warmer climates
• Old World
• Parasites a wide range of both domestic and wild animals
• Involved in the spread of Theileria and Babesia spp.
  • E.g. H. aegyptium is a parasite of tortoises in North Africa which has been spread around the world by the pet trade

References

• http://www.cfsph.iastate.edu/Factsheets/pdfs/boophilus_microplus.pdf