Ticks (Acari)

Abstract

The ticks are obligate, blood-feeding ectoparasites of vertebrates, particularly mammals and birds. Ticks are arachnids, in the sub-class Acari, closely related to the mites. They are usually relatively large and long-lived compared to mites, surviving for up to several years. During this time they feed periodically taking large blood meals, often with long intervals between each meal. Tick bites may be directly debilitating to domestic animals, causing mechanical damage, irritation, inflammation and hypersensitivity and, when present in large numbers, feeding may cause anaemia and reduced productivity (see section 3.4). The salivary secretions of some tick species may ]cause toxicosis and paralysis. However, ticks may also transmit a range of pathogenic viral, rickettsial and bacterial diseases to livestock. Hence, although the ticks are a relatively small order of only about 800 species, they are one of the most important groups of arthropod pests of veterinary interest.